Sleep Disturbance, Disability, and Posttraumatic Stress Disorder in Utility Workers Cezar Giosan,1,5 Loretta S. Malta,2 Katarzyna Wyka,3 Nimali Jayasinghe,3 Susan Evans,3 JoAnn Difede,3 and Eugen Avram4 1
Berkeley College Stratton VAMCV 3 Weill Medical College of Cornell University 4 University of Bucharest 5 Babes-Bolyai University 2
Objective:
The objective of the present study was to examine the associations between sleep disturbance, posttraumatic stress disorder (PTSD), and functional disability in a population exposed to a singular traumatic event. Method: The participants were a population of 2,453 predominantly male utility workers who were deployed to the World Trade Center site in the aftermath of the 9/11 attack. They underwent psychiatric screenings comprising measures of sleep disturbance, PTSD, and functional disability. Results: Analyses indicated that (a) rates of sleep disturbances were significantly higher among participants diagnosed with PTSD than those without, (b) PTSD severity was significantly associated with sleep disturbance, and (c) sleep disturbance moderated the relationship between PTSD and disability. Conclusion: Sleep disturbance is associated with occupational, social functioning, and PTSD severity, suggesting that ameliorating sleep may lead to increased occupational and social C 2014 Wiley Periodicals, Inc. J. Clin. functioning, as well as better treatment responses in PTSD. Psychol. 71:72–84, 2015. Keywords: sleep disturbance; PTSD; disability
Sleep impairment has been characterized as a core symptom of posttraumatic stress disorder (PTSD; Germain, Buysse, & Nofzinger, 2011; Mellman, 2008; Spoormaker & Montgomery, 2008). Sleep disturbances have been reported by survivors who were assessed after exposure to a variety of potentially traumatizing events, including combat (Inman, Silver, & Doghramji, 1990; MacLay, Klam, & Volkert, 2010; Neylan et al., 1998), natural disasters (Kato, Asukai, Miyake, Minakawa, & Nishiyama, 1996), vehicle accidents (Stein, 2002), and terrorist attacks (Difede, Roberts, Jayasinghe, & Leck, 2006). Difficulty initiating and/or maintaining sleep and sleep disruptions due to frequent nightmares are prevalent problems in trauma survivors with PTSD (Kilpatrick et al., 1998; MacLay et al., 2010; Pillar, Malhotra, & Lavie, 2000). Trauma survivors with PTSD frequently experience a range of comorbid sleep disorders, particularly insomnia (Lamarche & De Koninck, 2007; Maher, Rego, & Asnis, 2006). In one study, 80% of patients meeting criteria for lifetime PTSD reported insomnia (Leskin, Woodward, Young, & Sheikh, 2002). Commonly reported parasomnias in traumatized populations include nightmares (Goldstein, van Kammen, Shelly, Miller, & van Kammen, 1987; Krakow et al., 2000; Krakow, Melendrez, et al., 2001; Kuch & Cox, 1992; Neylan et al., 1998; North et al., 1999; Ohayon & Shapiro, 2000; Ross, Ball, Sullivan, & Caroff, 1989), excessive body movements (Beck, Steer, & Brown, 1996;
Resources for the completion of the final draft of this manuscript were partially covered by a grant of the Romanian Authority for Scientific Research, CNCS-UEFISCDI, Project number PN-II-ID-PCE-2011-30230. Please address correspondence to: Cezar Giosan, 12 East 41st Street, 16th Floor, New York, NY 10017. E-mail: [email protected] JOURNAL OF CLINICAL PSYCHOLOGY, Vol. 71(1), 72–84 (2015) Published online in Wiley Online Library (wileyonlinelibrary.com/journal/jclp).
C 2014 Wiley Periodicals, Inc. DOI: 10.1002/jclp.22116
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Inman et al., 1990; Lavie & Hertz, 1979; Mellman, David, Kulick-Bell, Hebding, & Nolan, 1995; Ross et al., 1989), and sleep disordered breathing (Krakow, Melendrez, et al., 2001; Krakow et al., 2002). During the past decade there has been increased interest in sleep disturbances in survivors with PTSD because greater sleep impairment has been associated with more severe PTSD, depression, suicidality, and health-related complaints (Goldstein et al., 1987; Kuch & Cox, 1992). Moreover, treatment outcomes for people with PTSD may be complicated by sleep disturbances. PTSD sufferers who seek treatment for sleep disturbances report more severe disturbances than other sleep-disordered and psychiatric samples (Koren, Arnon, Lavie, & Klein, 2002); and sleep disturbances in trauma survivors with PTSD may persist even after completion of PTSD treatments with demonstrated efficacy (Galovski, Monson, Bruce, & Resick, 2009; Zayfert & Deviva, 2004). A spate of studies during the past few years suggests that sleep impairment can improve if PTSD treatment is augmented with interventions that target specific types of sleep disturbances (DeViva, Zayfert, Pigeon, & Mellman, 2005; Gellis & Gerhman, 2011; Germain, Shear, Hall, & Buysse, 2007; Margolies, Rybarczyk, Vrana, Leszczyszyn, & Lynch, 2013; Perlman, Arnedt, Earnheart, Gorman, & Shirley, 2008; Ulmer, Edinger, & Calhoun, 2011). Similar findings have been reported for treatment-resistant insomnia associated with depression (Manber et al., 2008). There is growing evidence of a possible bidirectional relationship between sleep disturbances and PTSD. Early studies found that treatment of sleep disturbances also effectively reduced symptoms of PTSD (Krakow, Hollifield, et al., 2001; Neylan et al., 1998). During the past decade, longitudinal studies of trauma survivors have found that greater sleep impairment in the early months after trauma exposure predicts more severe PTSD symptoms at follow-up (Koren et al., 2002; Picchioni et al., 2010; Wright et al., 2011). Two recent studies that assessed military service personnel before and after they completed combat deployments found that self-reported predeployment sleep impairment significantly predicted the development of PTSD symptoms after combat deployments (Gehrman et al., 2013; Van Liempt, van Zuiden, Westenberg, Super, & Vermetten, 2013). These findings and an increased understanding of the role of sleep in the learning and consolidation of emotional memories (Pace-Schott et al., 2009; van der Helm & Walker, 2011) have lead some researchers to propose that sleep dysfunction may be a cause of PTSD, rather than merely a symptom of the disorder (Gehrman et al., 2013; Neylan, 2013; Picchioni et al., 2010; Van Liempt et al., 2013; Wright et al., 2011). However, a greater number of prospective studies that include objective measurement of sleep impairment are needed before strong conclusions about causality can be drawn (Babson & Feldner, 2010). The collected research findings do clearly suggest that it is important for mental health evaluations of trauma survivors to include careful assessment of sleep disturbances. This may have particular relevance for agencies tasked with the design and implementation of mental health programs for populations at risk of trauma exposure, such as military and law enforcement personnel and disaster responders. Assessment of sleep disturbances could improve the identification of those who will be more likely to require mental health treatment and could help to inform estimates of the amount, duration, and nature of posttrauma mental health resources that will be required. The present study investigated the relationship of sleep disturbances, PTSD, and functional impairment in utility workers. Utility workers are at increased risk of trauma exposure because they are required to restore power to regions struck by natural disasters and other types of mass traumas. Yet there is surprisingly little information about their mental health outcomes after exposure to the aftermath of events that may devastate entire communities. However, in the aftermath of the terrorist attack on September 11, 2001, an annual mandatory medical screening program was established for the approximately 3,500 utility workers who were deployed to the area surrounding the World Trade Center (WTC) to secure and restore power supplies to the downtown area of New York City. In addition to promoting the identification of workers in need of mental health services, the program provided an opportunity to study the development of PTSD and other mental health concerns in a novel trauma population. Research with this population found that 8% of utility
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workers developed symptoms that met diagnostic criteria for full PTSD and an additional 9% presented with enough clinically significant symptoms and impairment to be characterized as having subthreshold PTSD (Cukor et al., 2011; Difede et al., 2006). The present study augments research in this understudied trauma population with an investigation of the relationship between sleep disturbances, PTSD, and functional disability. The study hypotheses were as follows: (a) utility workers with PTSD will show more severe sleep disturbance than those without PTSD, (b) PTSD severity predicts sleep disturbance severity, and (c) PTSD status moderates the relationship between sleep disturbance severity and disability.
Method Participants Participants in this study were 2,453 utility workers who were deployed to the WTC site in the aftermath of the attack.
Procedure The evaluations were conducted as part of a larger study examining the psychological sequelae of the WTC attacks (Cukor et al., 2011; Difede et al., 2006). They comprised a comprehensive screening program, including a medical and a psychological evaluation, conducted under the auspices of the company’s Occupational Health department. The psychological evaluations, which were performed by doctoral-level clinical psychologists, were piggybacked onto annual fitness-for-duty evaluations for all utility workers who were deployed to work at the WTC in the aftermath of 9/11. They comprised self-report measures and structured clinical interviews. The clinical interviews took approximately 1 hour to complete. Workers completed psychiatric screenings approximately 29 months postdisaster (mean [M] = 29.4, standard deviation [SD] = 3.65). The psychiatric component of the evaluation was strictly voluntary and completely confidential. The sample in our study did not differ from the population from which it was drawn (Difede et al., 2006) on any demographic characteristics. The Institutional Review Board of Weill Medical College of Cornell University approved the review of medical records from the psychiatric screenings for research purposes.
Measures Administered Clinician-Administered PTSD Scale (CAPS). The CAPS is a structured interview for PTSD that yields both a dichotomous (present/absent) diagnosis of PTSD and a continuous measure of PTSD severity (Blake et al., 1995). The CAPS is a widely accepted criterion measure of PTSD with good psychometric properties (Weathers, Ruscio, & Keane, 1999). A number of different scoring rules for the CAPS have been developed and evaluated (Weathers, Keane, & Davidson, 2001; Weathers et al., 1999). For this study we focused on the original scoring rule (F1/12 rule), whereby an item with a frequency score of 1 or higher and an intensity score of 2 or higher is counted as a symptom toward a PTSD diagnosis. This rule, which involves the full Diagnostic and Statistical ManualIV (DSM-IV) criteria, requires that a participant meet all three cluster criteria (B, C, and D) for a diagnosis of PTSD. That is, participants were diagnosed with PTSD if they had at least one reexperiencing symptom (Criterion B), three avoidance and numbing symptoms (Criterion C), and two hyperarousal symptoms (Criterion D). In this study the CAPS was keyed to the WTC attack, not to general trauma, and therefore it assessed current PTSD in relation with this particular traumatic event. Trauma History Questionnaire. The Trauma History Questionnaire is a 13-item measure developed to document lifetime trauma history (Green, 1993). It inquires if the participant has ever witnessed or experienced any of the following 13 traumatic events: (a) natural disasters; (b) a serious accident/injury; (c) a sudden, life-threatening illness; (d) military combat or service in
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a war zone; (e) the death of a friend/family member in an accident or by murder; (f) the sudden, unexpected death of close family member; (g) assault with a weapon; (h) assault without a weapon; (i) childhood physical abuse; (j) childhood sexual abuse; (k) unwanted sexual contact coerced by verbal threat; (l) unwanted sexual contact coerced by physical force or threat of force; or (m) any other traumatic event. For the purposes of the present study, a dichotomous variable (history of trauma yes/no) was used in the statistical analyses. This measure has been shown to have acceptable reliability and validity in clinical and nonclinical samples (Stockton, Krupnick, & Green, 2011).
The Structured Clinical Interview for the DSM-IV (SCID). The SCID is a semistructured clinical interview designed to determine DSM-IV diagnoses (First, Spitzer, Williams, & Gibbon, 1997). Its psychometric properties have been well-established, with joint interview interrater reliability kappas between .70–.94 (Skre, Onstad, Torgersen, & Kringlen, 1991). The SCID and selected modules for the DSM-IV, which included major depression, panic disorder, and generalized anxiety disorder, were administered. The WTC Exposure Questionnaire. The WTC Exposure Questionnaire was developed by a panel of trauma experts to assess occupational exposure through performance of disaster work as well as personal exposure to the WTC attacks (e.g., loss of loved ones). The development of the exposure index in this study began with variables that were shown in the disaster literature to predict PTSD and revised with questions that emerged as unique to working at the WTC site (e.g., working on the “bucket brigade”). The aspects of occupational exposure are as follows: duration of work on the site; nature of work at the site; perception of danger while working at the site; witnessing bodies, body parts, body bags, or people jumping; and feeling disturbed by the smell at the site. The aspects of personal exposure are as follows: location during the attacks; presence of a loved one in the WTC or vicinity; injury or death to a family member, friend, or colleague; attendance at funerals/memorials; and displacement from home. The Sleep Index. The Sleep Index is a modified version of the Pittsburg Sleep Quality Index (PSQI; Buysse, Reynolds, Monk, Berman, & Kupfer, 1989) and was used to assess sleep disturbances and their frequency. The PSQI has been widely used to measure sleep difficulty in different populations (Chesson et al., 2000) and has good reliability and validity (Buysse et al., 1989; Doi et al., 2000). The modified version used in this study included the following items: 1. Cannot get to sleep within 30 minutes; 2. Wake up in the middle of the night or early morning with difficulty returning to sleep; 3. Snore loudly; 4. Awake after a reasonable amount of time in bed feeling unrefreshed; 5. Had bad or disturbing dreams; 6. Had an episode of sleepwalking; 7. Had a restless, creepy-crawling sensation in legs that interfered with falling or staying asleep; 8. Doze or nap during the course of the day; 9. Taken medication prescribed or over the counter; 10. Had trouble staying awake working, driving, eating meals, or engaging in social activity. The items were coded on a 4-point Likert scale ranging from 1 (not during the past month) to 4 (three or more times a week), reflecting severity of sleep disturbance. The Cronbach alpha for these 10 items was acceptable (Cronbach alpha = .78). The items were summed to yield a total sleep disturbance score and intrinsically different sleep disturbances were also coded (insomnia, items 1, 2; sleep-disordered breathing, item 3; parasomnias with nightmares, items 5, 6, 7). Sheehan Disability Scale (SDS). The SDS is a 10-point visual analogue scale that assesses disability across three domains: work, social life, and family life (Sheehan, 1983). The three items may be summed into a single dimensional measure of global functional impairment that ranges from 0 (unimpaired) to 30 (highly impaired). This scale has been widely used and has strong internal consistency (Cronbach’s alpha = 0.89 for the three-item scale). Analytical Strategy First, the prevalence of sleep disturbances was presented for the entire sample and by PTSD status. To compare severity of sleep disturbance in participants with and without PTSD,
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Table 1 Sociodemographic Characteristics Characteristics of sample (N = 2,453) Age, M (SD) Gender
45.84 (9.5) Male Female
97.1% 2.9%
Caucasian African American Hispanic Asian Other
65.7% 18.2% 12.9% 1.1% 2.2%
Some or no high school High school graduate Some college or training College graduate More than college
2.4% 47.7% 35.6% 11.3% 3.0%
Cohabitating Separated or divorced Married Widowed Single
1.3% 9.0% 71.1% .8% 17.8%
Race
Education
Marital Status
Note. M = mean; SD = standard deviation.
independent t tests were performed on an overall sleep disturbance score as well as severity ratings for individual sleep items. To evaluate whether PTSD was significantly associated with sleep disturbance, associates of sleep disturbance among available study variables were identified by performing Pearson correlations. Variables that achieved significance at the .05-level were entered in a stepwise hierarchical regression analysis with overall sleep disturbance severity as the dependent variable. A similar approach was used to examine whether predictors differed for specific categories of sleep disturbance: insomnia, sleep-disordered breathing, and parasomnias. For both sets of analysis, sleep-related items from the CAPS (distressing dreams, item 2; difficulty of falling or staying asleep, item 13) were subtracted from the total CAPS score to address the overlap between the Sleep Index and CAPS. Moderator analysis (Baron & Kenny, 1986) was performed to assess whether the relationship between disability and sleep was moderated by PTSD status. Moderator effect was assessed by the significance of the interaction between sleep disturbance severity and PTSD status. The analyses were adjusted for past and current psychopathology and trauma history. To calculate interrater reliability, a psychologist with 10 years’ experience using the CAPS made independent ratings while observing interviews. Intraclass correlations ranged from .98–.99 for the three symptom cluster severity scores and CAPS total severity.
Results The sample primarily comprised middle-aged, White, married, male high school graduates. (See Table 1 for more details.) Of the participants, 69% reported having experienced trauma unrelated to the WTC attacks. Cukor et al. (2011) showed that the exposure variables that best predicted PTSD in this population were as follows: (a) perception of life threat, (b) knowing someone at the WTC site in the moment of the attack, (c) participating in the Bucket Brigade, (d) seeing bodies, (e) knowing
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someone who was killed in the attack, and (f) seeing body parts. With respect to WTC attack and relief work, our sample reported the following: 34.4% felt that their life was in danger; 7.6% reported saw bodies; 17.6% saw body parts; 42.2% reported knowing someone whom they expected was in WTC vicinity at the time of the attack; 43.6% reported knowing someone who was killed; and 6.2% participated in the Bucket Brigade. In terms of psychiatric history and status, 10.8% were assessed with past major depression, 6.3% with past panic disorder, and 2.4% with past generalized anxiety disorder. Of the participants, 87 (3.9%) met criteria for current major depression and 34 (1.38%) met criteria for both PTSD and depression.
Sleep Disturbance and PTSD The mean Sleep Index score was 14.23(4.85). Of the total group, 125 (5.1%) met criteria for PTSD, which is higher than the estimated 3.5% for men and women, or 1.8% for men in the general population (Kessler, Chiu, Demler, Merikangas, & Walters, 2005). The prevalence of sleep disturbance in the PTSD, non-PTSD, and the entire sample is presented in Table 2. The disturbances most often reported by the PTSD sample as happening three or more times a week were as follows: insomnia (46.3%); waking up early morning or during the night (43.8%); snoring loudly (38.7%); and feeling unrefreshed after sleep (35.0%). Table 3 shows that the PTSD group had significantly more severe sleep disturbance on every dimension measure compared to the non-PTSD group, confirming Hypothesis 1.
Association of Sleep Disturbance, Prior Trauma, Psychiatric History, and Exposure Statistically significant correlations were found between severity of sleep disturbance and the following: education and race/ethnicity (inverse), prior trauma, depression (current and past), panic (current and past), generalized anxiety disorder (current and past), and CAPS total severity score (see Table 4).
Predictors of Sleep Disturbance After controlling for demographics, prior trauma, and past and current psychopathology, the CAPS total severity score (with sleep items removed) emerged as a significant predictor of sleep disturbance, confirming Hypothesis 2 (Table 5). Regression analyses also showed that CAPS total severity score (with sleep items removed) predicts insomnia (R2 = .31, F = 37.99, β = .49, t = 18.16, p = .01), sleep-disordered breathing (R2 = .08, F = 7.68, β = .25, t = 8.02, p = .01), and parasomnias (R2 = .27, F = 31.23, β = .45, t = 16.40, p = .01).
Sleep Disturbance and Disability Bivariate correlations between the Sheehan Disability Scale and the Sleep Index suggested that people with sleep disturbance reported significantly higher disability levels (r = .58, p < .01). This relation was observed in workers both diagnosed with PTSD (r = 0.49, p < .01) and those with no diagnosis of PTSD (r = 0.49, p < .01). After controlling for demographic variables, past and current psychopathology, and trauma history, moderator regression analysis showed that the relationship between sleep disturbance and disability level is positive and significantly stronger for individuals with PTSD (interaction b = .223, standard error [SE] = .104, p < .001; Table 6).
Discussion Several important findings emerged from this study examining the complex relationship between sleep, PTSD, and disability. First, the rates of PTSD in our population exposed to WTCrelated trauma are higher (5.1%) than the 12-month PTSD prevalence in the general population, estimated at 3.5% for men and women or 1.8% for men (Kessler et al., 2005).
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Table 2 Prevalence of Sleep Disturbance Rates in the PTSD Sample, Non-PTSD Sample, and the Entire Sample
Sleep disturbance Insomnia (difficulties falling asleep within 30 minutes) Waking up early morning or during the night Snoring loudly
Feeling unrefreshed after sleep
Disturbing dreams
Sleep-walking episodes
Restless sensation in legs
Dozing or napping
Taking sleeping pills
Having trouble staying awake while working, driving, eating, or engaging in social activities
Frequency
Entire sample (n = 2,453) %
Non-PTSD sample (n = 2,198) %
PTSD sample (n = 125) %
Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week
68.1 11.7 11.5 8.7 65.9 14.0 12.4 7.8 59.1 10.8 11.5 18.6 62.0 16.0 13.6 8.4 79.9 12.8 5.6 1.6 98.9 .8 .2 .0 93.4 3.8 1.9 .9 55.2 18.0 15.3 11.5 93.0 2.7 2.0 2.3 85.6 7.4 4.8 2.3
70.8 12.1 10.7 6.4 69.0 14.1 11.1 5.8 60.7 10.7 11.0 17.6 64.8 16.3 11.8 7.1 83.0 11.9 4.0 1.0 99.1 .7 .2 .0 94.5 3.2 1.7 .6 56.8 18.0 14.9 10.4 93.9 2.6 1.5 2.0 87.4 6.9 4.1 1.6
19.5 7.3 26.8 46.3 9.1 10.7 36.4 43.8 24.5 16.0 20.8 38.7 9.2 15.0 40.8 35.0 23.3 30.0 33.3 13.3 95.0 3.3 1.7 0.0 73.6 14.0 6.6 5.8 29.8 15.7 22.3 32.2 77.0 4.1 9.8 9.0 51.2 17.1 17.1 14.6
Note. PTSD = posttraumatic stress disorder.
Second, those utility workers diagnosed with WTC-related PTSD as assessed by CAPS reported higher rates of nightmares, sleep-disordered breathing, and parasomnias those without PTSD. Among those not diagnosed with PTSD, the prevalence of sleep disorders is consistent with that found in the general population. For instance, the National Institutes of Health’s 2003 National Sleep Disorders Research Plan (NSDRP, 2003) estimates that anywhere between 30% and 40% of the general population suffers from insomnia. Our non-PTSD sample had a 29.2% prevalence of insomnia. Likewise, the NSDRP puts restless legs between at between 2% and
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Table 3 Sleep Disturbance Severity (Total and Individual Sleep Items) by PTSD Group No PTSD
Sleep Index total score Cannot get to sleep in 30 minutes Wake up middle night or early morning Snores loudly Feel unrefreshed Disturbing dreams Sleepwalking Restless sensation in legs Dozes or naps Took sleeping pills past month Had trouble staying awake past month
PTSD
Mean
SD
Mean
SD
t
13.79 1.53 1.54 1.85 1.61 1.23 1.01 1.08 1.79 1.12 1.20
4.44 .92 .90 1.18 .95 .57 .14 .39 1.04 .50 .58
22.15 3.00 3.15 2.74 3.02 2.37 1.07 1.45 2.57 1.51 1.95
4.81 1.15 .95 1.21 .94 .98 .31 .86 1.22 .99 1.13
−18.78** −17.00** −19.04** −7.46** −15.78** −20.36** −3.86** −9.12** −7.95** −7.84** −13.03**
Note. PTSD = posttraumatic stress disorder; M = mean; SD = standard deviation. *p < .05. **p < .01.
Table 4 Correlation Table Between Sleep Index Total Score and Demographic and Psychiatric Variables
Sleep Index
Sleep Index
Race
Education
Marital status
Age
Gender
Trauma
Past depression
Current depression
−.04*
−.05*
−.01
.03
.01
.21**
.18**
.29**
Past panic
Current panic
Past GAD
Current GAD
CAPS–total severity score (sleep items removed)
.16**
.17**
.11**
.16**
.58**
Note. GAD = general anxiety disorder; CAPS = Clinician-Administered PTSD Scale. *p < .05. **p < .01.
Table 5 Hierarchical Regression of Sleep Disturbance on CAPS Total Severity Score
Step 1
R2
F
.004
3.07
.05
22.15
.08
21.01
Education Step 2 Trauma Step 3 Past major depression Past panic disorder Past GAD Step 4
.15
.35 CAPS–total severity score (sleep items removed)
Note. CAPS = Clinician-Administered PTSD Scale. *p < .05. **p < .01.
t
−.050
−1.96*
.20
7.75**
.11 .10 .07
4.06** 3.61** 2.53**
.22 .07 .07
8.16** 2.59** 2.69**
.52
20.97**
26.40
Current major depression Current panic disorder Current GAD Step 6
β
75.32
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Table 6
Regression Analysis of Sleep Disturbance on Disability Total Score Moderated by PTSD Status∗
Step 1
R2
F
.034
15.06
.10
22.92
Trauma Step 2
.043
Past major depression Past panic disorder Past GAD Step 3
.266
.480 Sleep Index CAPS–total severity score (sleep items removed) Sleep Index* CAPS–total severity score (sleep items removed)
t 2.044*
.073 −.041 .016
3.356** −1.884 .709
.212 .011 .083
9.306** .514 3.668**
.374 .004
15.390** .038
.232
2.186*
51.06
Current major depression Current panic disorder Current GAD Step 4
β
97.56
Note. PTSD = posttraumatic stress disorder; GAD = general anxiety disorder; CAPS = ClinicianAdministered PTSD Scale. ∗ Regression analysis adjusted for demographic variables. *p < .05. **p < .01.
15%, while our non-PTSD sample reported this symptom in 5.5% of the cases. Furthermore, sleep disturbance severity was significantly higher amongst individuals with PTSD. Third, another finding that emerged from the study is that PTSD severity was significantly associated with sleep disturbance and with intrinsically different sleep disturbances. Although our study lacked objective measures of sleep disturbance, the findings as a group are consistent with mounting evidence that fear and sleep mechanisms share and interact in important ways that may account for the comorbidity of PTSD, nightmares, and sleep disordered breathing (Woodward, 2004). Last, a positive association between sleep disturbance and self-reported functional disability was found. This association was found in both the PTSD and the non-PTSD sample, but moderator analyses revealed that this association is stronger for individuals with PTSD, compared to those without PTSD.
Limitations Limitations to the current study include the cross-sectional nature of sample. As noted, sleep disturbances that are either preexisting (Gehrman et al., 2013) or develop after trauma exposure (Koren et al., 2002; Picchioni et al., 2010; Wright et al., 2011) have been linked to the development of PTSD. The cross-sectional design of this study did not permit the authors to address the causal relationship between PTSD, sleep disturbance, and disability. Moreover, the assessment of sleep impairment did not include data on whether any of the reported sleep problems developed prior to trauma exposure. Other limitations relate to the sample demographics, because this study primarily focused on White, middle-aged utility workers, and therefore the results may not generalize to other populations. Another limitation of this study is the lack of information on premorbid sleep disturbance. The constraints of the data collection process did not allow for gathering information about premorbid sleep disturbance, which may have an effect on the relationships examined in this study. Also, another limitation is the fact that sleep disturbance was assessed through a
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self-report instrument. More objective measures of sleep disturbances may shed further light on their associations with PTSD. Finally, the risk factors for sleep apnea are being male and older than 40 years of age. The sleep apnea prevalence estimate in the general population is 4% in men (Alvi & Lee, 2006), which is lower than what we have found in our sample. Some research suggests that sleep apnea may be more prevalent in trauma victims (Krakow et al., 2002). As our predominantly male sample had a mean age of 46 years, sleep apnea, which we had no way of testing, may be an unexamined variable that accounts for some of our findings. Further research needs to be done to examine the potential contribution of sleep apnea in this population.
Conclusion Despite these limitations, however, this study shows that sleep disturbance is associated with occupational and social functioning, as well as with PTSD severity. These associations suggest that ameliorating sleep may lead to increased occupational and social functioning. Furthermore, the indications that sleep disturbances are core clinical features of PTSD raise the possibility that treatment response in PTSD may be aided by sleep-focused assessments and intervention strategies. Further research is warranted to examine treatments aimed at targeting sleep disturbance and the potential role in improving functioning in work and social areas.
References Alvi, A., & Lee, S. E. (2006). Putting sleep apnea to rest: Tailored therapy reduces fatigue-related risks. Postgraduate Medicine, 119, 46–53. American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders DSM-IVTR. (4th ed.). Washington, DC: American Psychiatric Association. Babson, K. A., & Feldner, M. T. (2010). Temporal Relations between sleep problems and both traumatic event exposure and PTSD: A critical review of the empirical literature. Journal of Anxiety Disorders, 24, 1–15. doi:10.1016/j.janxdis.2009.08.002 Baron, R. M., & Kenny, D. A. (1986). The moderator-mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51, 1173–1182. doi:10.1037/0022-3514.51.6.1173 Beck, A. T., Steer, R. A., & Brown, G. K. (1996). Manual for the Beck Depression Inventory. San Antonio, TX: The Psychological Corporation. Blake, D. D., Weathers, F. W., Nagy, L. M., Kaloupek, D. G., Gusman, F. D., Charney, D. S., et al. (1995). The development of a clinician-administered PTSD scale. Journal of Traumatic Stress, 8, 75–90. doi:10.1002/jts.2490080106 Buysse, D. J., Reynolds, C. F., Monk, T. H., Berman, S. R., & Kupfer, D. J. (1989). The Pittsburgh Sleep Quality Index: A new instrument for psychiatric practice and research. Psychiatry Research, 28, 193–213. doi:10.1016/0165-1781(89)90047-4 Chesson, A., Hartse, K., Anderson, W. M., Davila, D., Johnson, S., Littner, M., & et al. (2000). Practice parameters for the evaluation of chronic insomnia: An American Academy of Sleep Medicine Report. Standards of Practice Committee of the American Academy of Sleep Medicine. Sleep, 23, 237–241. Cukor, J., Wyka, K., Jayasinghe, N., Weathers, F., Giosan, C., Leck, P., . . . Difede, J. (2011). Prevalence and predictors of posttraumatic stress symptoms in utility workers deployed to the World Trade Center following the attacks of September 11, 2001. Depression and Anxiety, 28, 210–217. doi:10.1002/da.20776 DeViva, J. C., Zayfert, C., Pigeon, W. R., & Mellman, T. A. (2005). Treatment of residual insomnia after CBT for PTSD: Case studies. Journal of Traumatic Stress, 18, 155–159. doi:10.1002/jts.20015 Difede, J., Roberts, J., Jayasinghe, N., & Leck, P. (2006). Evaluation and treatment of firefighters and utility workers following the World Trade Center attacks. In Y. Neria, R. Marshall, & E. Susser (Eds.), Mental health in the wake of terrorist attacks. New York: Cambridge University Press. Retrieved from http://dx.doi.org/10.1017/CBO9780511544132.022 Doi, Y., Minowa, M., Uchiyama, M., Okawa, M., Kim, K., Shimui, K., & et al. (2000). Psychometric assessment of subjective sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects. Psychiatry Research, 97, 165–172.
82
Journal of Clinical Psychology, January 2015
First, M. B., Spitzer, R. L., Williams, J. B. W., & Gibbon, M. (1997). Structured clinical interview for DSM-IV SCID. Washington, DC: American Psychological Association. Galovski, T. E., Monson, C., Bruce, S. R., & Resick, P. A. (2009). Does cognitive-behavioral therapy for PTSD improve perceived health and sleep impairment? Journal of Traumatic Stress, 22, 197–204. doi:10.1002/jts.20418 Gehrman, P., Seelig, A. D., Jacobson, I. G., Boyko, E. J., Hooper, T. I., Gacksetter, G. D., . . . for the Millenium COhort Study Team. (2013). Predeployment sleep duration and insomnia symptoms as risk factors for new-onset mental health disorders following military deployment. Sleep, 36, 1009–1018. Gellis, L. A., & Gerhman, P. R. (2011). Cognitive behavioral treatment for insomnia in veterans with longstanding posttraumatic stress disorder: a pilot study. Journal of Aggression, Maltreatment & Trauma, 20, 904–916. Germain, A., Buysse, D. J., & Nofzinger, E. (2011). Sleep–specific mechanisms underlying posttraumatic stress disorder: Integrative review and neurobiological hypotheses. Sleep Medicine Reviews, 12, 185–195. doi:10.1016/j.smrv.2007.09.003 Germain, A., Shear, M. K., Hall, M., & Buysse, D. J. (2007). Effects of a brief behavioral treatment for PTSD-related sleep disturbances: A pilot study. Journal of Behavior Research and Therapy, 45, 627–632. doi:10.1016/j.brat.2006.04.009 Goldstein, G., van Kammen, W., Shelly, C., Miller, D. J., & van Kammen, D. P. (1987). Survivors of imprisonment in the Pacific Theater during World War II. American Journal of Psychiatry, 144, 1210– 1213. Green, B. L. (1993). Trauma History Questionnaire. In Instrumentation in Stress, Trauma and Adaptation (pp. 366–369). Northbrook, IL: Research and Methodology Interest Group of the ISTSS. Inman, D. J., Silver, S. M., & Doghramji, K. (1990). Sleep disturbance in post-traumatic stress disorder: A comparison with non-PTSD insomnia. Journal of Traumatic Stress, 3, 429–437. doi:10.1002/jts.2490030311 Kato, H., Asukai, N., Miyake, Y., Minakawa, K., & Nishiyama, A. (1996). Post-traumatic symptoms among younger and elderly evacuees in the early stages following the 1995 Hanshin-Awaji earthquake in Japan. Acta Psychiatrica Scandinavica, 93, 477–481. doi:10.1111/j.1600-0447.1996.tb10680.x Kessler, R. C., Chiu, W. T., Demler, O., Merikangas, K. R., & Walters, E. E. (2005). Prevalence, severity, and comorbidity of 12-month DSM-IV disorders in the National Comorbidity Survey Replication. Archives of General Psychiatry, 62, 617–627. doi:10.1001/archpsyc.62.6.617 Kilpatrick, D., Resnick, H., Freedy, J., Pelcovitz, D., Resick, P., Roth, S., & et al. (1998). Posttraumatic stress disorder field trial: Evaluation of the PTSD construct-criteria A through E. In T. A. Widiger, A. J. Frances, H. A. Pincus, R. Ross, M. B. First, W. Davis, & M. Kline (Eds.), DSM-IV Sourcebook. Washington, DC: American Psychiatric Press. Koren, D., Arnon, I., Lavie, P., & Klein, E. (2002). Sleep complaints as early predictors of posttraumatic stress disorder: A 1 year prospective study of injured survivors of motor vehicle accidents. American Journal of Psychiatry, 159, 855–857. doi:10.1176/appi.ajp.159.5.855 Krakow, B., Artar, A., Warner, T. D., Melendrez, D., Johnston, L., Hollifield, M., & et al. (2000). Sleep disorder, depression, and suicidality in female sexual assault survivors. Crisis, 21, 163–170. Krakow, B., Hollifield, M., Johnston, L., Koss, M., Shrader, R., Warner, T. D., & et al. (2001). A randomized controlled study of imagery rehearsal therapy for chronic nightmares in sexual assault survivors with posttraumatic stress disorder. JAMA, 286, 537–545. doi:10.1023/A:1007854015481 Krakow, B., Melenderez, D., Johnston, L., Warner, T., Clark, J., Pacheco, M., & et al. (2002). Sleepdisordered breathing, psychiatric distress and quality of life impairment in sexual assault survivors. Journal of Nervous Mental Health Disease, 190, 442–452. Krakow, B., Melendrez, D., Pedersen, B., Johnston, L., Hollifield, M., Germain, A., . . . Schrader, R. (2001). Complex insomnia: Insomnia and sleep-disordered breathing in a consecutive series of crime victims with nightmares and PTSD. Biological Psychiatry, 49, 948–953. doi:10.1097/00005053-200207000-00004 Kuch, K., & Cox, B. J. (1992). Symptoms of PTSD in 124 survivors of the holocaust. American Journal of Psychiatry, 149, 337–340. Lamarche, L. J., & De Koninck, J. (2007). Sleep disturbances in patients with post- traumatic stress disorder epidemiology, impact and approaches to management. Journal of Clinical Psychiatry, 68, 1257–1270. doi:http://dx.doi.org/10.4088/JCP.v68n0813 Lavie, P., & Hertz, G. (1979). Increased sleep motility and respiration rates in combat neurotic patients. Biological Psychiatry, 14, 983–987.
Sleep Disturbance, PTSD, and Disability
83
Leskin, G., Woodward, S. H., Young, H., & Sheikh, J. I. (2002). Effects of comorbid diagnoses on sleep disturbance in PTSD. Psychiatric Research, 36, 449–452. doi:10.1016/S0022-3956(02)00025-0 MacLay, R. N., Klam, W. P., & Volkert, S. L. (2010). Insomnia is the most commonly reported symptom and predicts other symptoms of post-traumatic stress disorder in U.S. service members returning from military deployments. Military Medicine, 175, 759–762. Maher, M. J., Rego, S. A., & Asnis, G. M. (2006). Sleep disturbances in patients with post- traumatic stress disorder: Epidemiology, impact and approaches to management. CNS Drugs, 20, 567–590. doi:10.2165/00023210-200620070-00003 Manber, R., Edinger, J. D., Gress, J. L., San Pedro-Salcedo, M. G., Kuo, T. F., & Kalista, T. (2008). Cognitive behavioral therapy for insomnia enhances depression outcome in patients with comorbid major depressive disorder and insomnia. Sleep, 31, 489–495. doi:10.1001/archpsyc.65.5.551 Margolies, S. O., Rybarczyk, B., Vrana, S. R., Leszczyszyn, D. J., & Lynch, J. (2013). Efficacy of a cognitivebehavioral treatment for insomnia and nightmares in Afghanistan and Iraq veterans with PTSD. Journal of Clinical Psychology, 69, 1026–1042. doi:10.1002/jclp.2197 Mellman, T. A. (2008). Sleep and post-traumatic stress disorder: A roadmap for clinicians and researchers. Sleep Medicine Reviews, 12, 165–167. Mellman, T. A., David, D., Kulick-Bell, R., Hebding, J., & Nolan, B. (1995). Sleep disturbance and its relationship to psychiatric morbidity after Hurricane Andrew. American Journal of Psychiatry, 152, 1659–1663. National Sleep Disorders Research Plan. (2003). 2003 National Sleep Disorders Research Plan. Retrieved from http://www.nhlbi.nih.gov/health/prof/sleep/res_plan/sleep-rplan.pdf Neylan, T. C. (2013). Sleep and psychological vulnerability to traumatic stress. Commentary on Gehrman et al. Predeployment sleep duration and insomnia symptoms as risk factors for new-onset mental health disorders following military deployment. Sleep, 36, 1009–1018. Neylan, T. C., Marmar, C. R., Metzler, T. J., Weiss, D. S., Zatzick, D. F., Delucchi, K. L., & et al. (1998). Sleep disturbances in the Vietnam generation: findings from a nationally representative sample of male Vietnam veterans. American Journal of Psychiatry, 155, 929–933. North, C. S., Nixon, S., Shariat, S., Mallonee, S., McMillen, J. C., Spitznagel, E. L., & et al. (1999). Psychiatric disorders among survivors of the Oklahoma City bombing. Journal of the American Medical Association, 282, 755–762. Ohayon, M. M., & Shapiro, C. M. (2000). Sleep disturbances in psychiatric disorders associated with posttraumatic stress disorder in the general population. Comprehensive Psychiatry, 41, 469–478. doi:http://dx.doi.org/10.1053/comp.2000.16568 Pace-Schott, E. F., MIlad, M. R., Orr, S. P., Rauch, S. L., Stickgold, R., & Pitman, R. K. (2009). Sleep promotes generalization of extinction of conditioned fear. Sleep, 32, 19–26. Perlman, L. M., Arnedt, J. T., Earnheart, K. L., Gorman, A. A., & Shirley, K. G. (2008). Group cognitive behavioral therapy for insomnia in a VA mental health clinic. Cognitive and Behavioral Practice, 15, 426–434. doi:10.1016/j.cbpra.2008.05.003 Picchioni, D., Cabrera, O. A., McGurk, D., Thomas, J. L., Castro, C. A., Balkin, T. J., . . . Hoge, C. W. (2010). Sleep symptoms as partial mediator between combat stressors and other mental health symptoms in Iraq War veterans. Military Psychology, 22, 340–355. Pillar, G., Malhotra, A., & Lavie, P. (2000). Post-traumatic stress disorder and sleep–What a nightmare! Sleep Medicine Reviews, 4, 183–200. doi:10.1053/smrv.1999.0095 Ross, R. J., Ball, W. A., Sullivan, K. A., & Caroff, S. N. (1989). Sleep disturbances, the hallmark of posttraumatic stress disorder. American Journal of Psychiatry, 146, 1179–1196. Sheehan, D. V. (1983). The anxiety disease. New York: Scribner’s. Skre, I., Onstad, S., Torgersen, S., & Kringlen, E. (1991). High interrater reliability for the Structured Clinical Interview for DSM-III-R Axis I (SCID-I). Acta Psychiatrica Scandinavica, 84(2), 167–173. Spoormaker, V. I., & Montgomery, P. (2008). Disturbed sleep in post-traumatic stress disorder: Secondary symptom or core feature? Sleep Medicine Reviews, 12, 169–184. doi:10.1016/j.smrv.2007.08.008 Stein, M. B. (2002). A 46-year-old man with anxiety and nightmares after a motor vehicle collision. JAMA, 288, 1513. doi:10.1001/jama.288.12.1513 Stockton, P., Krupnick, J. L., & Green, B. L. (2011). Development, use, and psychometric properties of the Trauma History Questionnaire. Journal of Loss and Trauma, 16, 258–283. Ulmer, C. S., Edinger, J. D., & Calhoun, P. S. (2011). A multi-component cognitive behavioral intervention for sleep disturbance in veterans with PTSD: A pilot study. Journal of Clinical Sleep Medicine, 7, 57–68.
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Van der Helm, E., & Walker, M. P. (2011). Sleep and emotional memory processing. Sleep Medicine Clinics, 6, 31–43. doi:10.1016/j.jsmc.2010.12.010 Van Liempt, S., van Zuiden, M., Westenberg, H., Super, A., & Vermetten, E. (2013). Impact of impaired sleep on the development of PTSD symptoms in combat veterans: A prospective longitudinal cohort study. Depression and Anxiety, 30, 469–474. doi:10.1002/da.22054 Weathers, F. W., Keane, T. M., & Davidson, J. (2001). Clinician-Administered PTSD Scale: A review of the first ten years of research. Depression and Anxiety, 13, 132–156. doi:10.1002/da.1029 Weathers, F. W., Ruscio, A. M., & Keane, T. M. (1999). Psychometric properties of nine scoring rules for the Clinician-Administered Posttraumatic Stress Disorder Scale. Psychological Assessment, 11, 124–133. doi:10.1037/1040-3590.11.2.124 Woodward, S. (2004). PTSD sleep research: An update. PTSD Research Quarterly, 15, 1–8. Wright, K. M., Britt, T. W., Bliese, P. D., Adler, A. B., Picchioni, D., & Moore, D. (2011). Insomnia as predictor versus outcome of PTSD and depression among Iraq combat veterans. Journal of Clinical Psychology, 67, 1240–1258. doi:10.1002/jclp.20845 Zayfert, C., & Deviva, J. C. (2004). Residual insomnia following cognitive behavioral therapy for PTSD. Journal of Traumatic Stress, 17, 69–73.
Berkeley College Stratton VAMCV 3 Weill Medical College of Cornell University 4 University of Bucharest 5 Babes-Bolyai University 2
Objective:
The objective of the present study was to examine the associations between sleep disturbance, posttraumatic stress disorder (PTSD), and functional disability in a population exposed to a singular traumatic event. Method: The participants were a population of 2,453 predominantly male utility workers who were deployed to the World Trade Center site in the aftermath of the 9/11 attack. They underwent psychiatric screenings comprising measures of sleep disturbance, PTSD, and functional disability. Results: Analyses indicated that (a) rates of sleep disturbances were significantly higher among participants diagnosed with PTSD than those without, (b) PTSD severity was significantly associated with sleep disturbance, and (c) sleep disturbance moderated the relationship between PTSD and disability. Conclusion: Sleep disturbance is associated with occupational, social functioning, and PTSD severity, suggesting that ameliorating sleep may lead to increased occupational and social C 2014 Wiley Periodicals, Inc. J. Clin. functioning, as well as better treatment responses in PTSD. Psychol. 71:72–84, 2015. Keywords: sleep disturbance; PTSD; disability
Sleep impairment has been characterized as a core symptom of posttraumatic stress disorder (PTSD; Germain, Buysse, & Nofzinger, 2011; Mellman, 2008; Spoormaker & Montgomery, 2008). Sleep disturbances have been reported by survivors who were assessed after exposure to a variety of potentially traumatizing events, including combat (Inman, Silver, & Doghramji, 1990; MacLay, Klam, & Volkert, 2010; Neylan et al., 1998), natural disasters (Kato, Asukai, Miyake, Minakawa, & Nishiyama, 1996), vehicle accidents (Stein, 2002), and terrorist attacks (Difede, Roberts, Jayasinghe, & Leck, 2006). Difficulty initiating and/or maintaining sleep and sleep disruptions due to frequent nightmares are prevalent problems in trauma survivors with PTSD (Kilpatrick et al., 1998; MacLay et al., 2010; Pillar, Malhotra, & Lavie, 2000). Trauma survivors with PTSD frequently experience a range of comorbid sleep disorders, particularly insomnia (Lamarche & De Koninck, 2007; Maher, Rego, & Asnis, 2006). In one study, 80% of patients meeting criteria for lifetime PTSD reported insomnia (Leskin, Woodward, Young, & Sheikh, 2002). Commonly reported parasomnias in traumatized populations include nightmares (Goldstein, van Kammen, Shelly, Miller, & van Kammen, 1987; Krakow et al., 2000; Krakow, Melendrez, et al., 2001; Kuch & Cox, 1992; Neylan et al., 1998; North et al., 1999; Ohayon & Shapiro, 2000; Ross, Ball, Sullivan, & Caroff, 1989), excessive body movements (Beck, Steer, & Brown, 1996;
Resources for the completion of the final draft of this manuscript were partially covered by a grant of the Romanian Authority for Scientific Research, CNCS-UEFISCDI, Project number PN-II-ID-PCE-2011-30230. Please address correspondence to: Cezar Giosan, 12 East 41st Street, 16th Floor, New York, NY 10017. E-mail: [email protected] JOURNAL OF CLINICAL PSYCHOLOGY, Vol. 71(1), 72–84 (2015) Published online in Wiley Online Library (wileyonlinelibrary.com/journal/jclp).
C 2014 Wiley Periodicals, Inc. DOI: 10.1002/jclp.22116
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Inman et al., 1990; Lavie & Hertz, 1979; Mellman, David, Kulick-Bell, Hebding, & Nolan, 1995; Ross et al., 1989), and sleep disordered breathing (Krakow, Melendrez, et al., 2001; Krakow et al., 2002). During the past decade there has been increased interest in sleep disturbances in survivors with PTSD because greater sleep impairment has been associated with more severe PTSD, depression, suicidality, and health-related complaints (Goldstein et al., 1987; Kuch & Cox, 1992). Moreover, treatment outcomes for people with PTSD may be complicated by sleep disturbances. PTSD sufferers who seek treatment for sleep disturbances report more severe disturbances than other sleep-disordered and psychiatric samples (Koren, Arnon, Lavie, & Klein, 2002); and sleep disturbances in trauma survivors with PTSD may persist even after completion of PTSD treatments with demonstrated efficacy (Galovski, Monson, Bruce, & Resick, 2009; Zayfert & Deviva, 2004). A spate of studies during the past few years suggests that sleep impairment can improve if PTSD treatment is augmented with interventions that target specific types of sleep disturbances (DeViva, Zayfert, Pigeon, & Mellman, 2005; Gellis & Gerhman, 2011; Germain, Shear, Hall, & Buysse, 2007; Margolies, Rybarczyk, Vrana, Leszczyszyn, & Lynch, 2013; Perlman, Arnedt, Earnheart, Gorman, & Shirley, 2008; Ulmer, Edinger, & Calhoun, 2011). Similar findings have been reported for treatment-resistant insomnia associated with depression (Manber et al., 2008). There is growing evidence of a possible bidirectional relationship between sleep disturbances and PTSD. Early studies found that treatment of sleep disturbances also effectively reduced symptoms of PTSD (Krakow, Hollifield, et al., 2001; Neylan et al., 1998). During the past decade, longitudinal studies of trauma survivors have found that greater sleep impairment in the early months after trauma exposure predicts more severe PTSD symptoms at follow-up (Koren et al., 2002; Picchioni et al., 2010; Wright et al., 2011). Two recent studies that assessed military service personnel before and after they completed combat deployments found that self-reported predeployment sleep impairment significantly predicted the development of PTSD symptoms after combat deployments (Gehrman et al., 2013; Van Liempt, van Zuiden, Westenberg, Super, & Vermetten, 2013). These findings and an increased understanding of the role of sleep in the learning and consolidation of emotional memories (Pace-Schott et al., 2009; van der Helm & Walker, 2011) have lead some researchers to propose that sleep dysfunction may be a cause of PTSD, rather than merely a symptom of the disorder (Gehrman et al., 2013; Neylan, 2013; Picchioni et al., 2010; Van Liempt et al., 2013; Wright et al., 2011). However, a greater number of prospective studies that include objective measurement of sleep impairment are needed before strong conclusions about causality can be drawn (Babson & Feldner, 2010). The collected research findings do clearly suggest that it is important for mental health evaluations of trauma survivors to include careful assessment of sleep disturbances. This may have particular relevance for agencies tasked with the design and implementation of mental health programs for populations at risk of trauma exposure, such as military and law enforcement personnel and disaster responders. Assessment of sleep disturbances could improve the identification of those who will be more likely to require mental health treatment and could help to inform estimates of the amount, duration, and nature of posttrauma mental health resources that will be required. The present study investigated the relationship of sleep disturbances, PTSD, and functional impairment in utility workers. Utility workers are at increased risk of trauma exposure because they are required to restore power to regions struck by natural disasters and other types of mass traumas. Yet there is surprisingly little information about their mental health outcomes after exposure to the aftermath of events that may devastate entire communities. However, in the aftermath of the terrorist attack on September 11, 2001, an annual mandatory medical screening program was established for the approximately 3,500 utility workers who were deployed to the area surrounding the World Trade Center (WTC) to secure and restore power supplies to the downtown area of New York City. In addition to promoting the identification of workers in need of mental health services, the program provided an opportunity to study the development of PTSD and other mental health concerns in a novel trauma population. Research with this population found that 8% of utility
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workers developed symptoms that met diagnostic criteria for full PTSD and an additional 9% presented with enough clinically significant symptoms and impairment to be characterized as having subthreshold PTSD (Cukor et al., 2011; Difede et al., 2006). The present study augments research in this understudied trauma population with an investigation of the relationship between sleep disturbances, PTSD, and functional disability. The study hypotheses were as follows: (a) utility workers with PTSD will show more severe sleep disturbance than those without PTSD, (b) PTSD severity predicts sleep disturbance severity, and (c) PTSD status moderates the relationship between sleep disturbance severity and disability.
Method Participants Participants in this study were 2,453 utility workers who were deployed to the WTC site in the aftermath of the attack.
Procedure The evaluations were conducted as part of a larger study examining the psychological sequelae of the WTC attacks (Cukor et al., 2011; Difede et al., 2006). They comprised a comprehensive screening program, including a medical and a psychological evaluation, conducted under the auspices of the company’s Occupational Health department. The psychological evaluations, which were performed by doctoral-level clinical psychologists, were piggybacked onto annual fitness-for-duty evaluations for all utility workers who were deployed to work at the WTC in the aftermath of 9/11. They comprised self-report measures and structured clinical interviews. The clinical interviews took approximately 1 hour to complete. Workers completed psychiatric screenings approximately 29 months postdisaster (mean [M] = 29.4, standard deviation [SD] = 3.65). The psychiatric component of the evaluation was strictly voluntary and completely confidential. The sample in our study did not differ from the population from which it was drawn (Difede et al., 2006) on any demographic characteristics. The Institutional Review Board of Weill Medical College of Cornell University approved the review of medical records from the psychiatric screenings for research purposes.
Measures Administered Clinician-Administered PTSD Scale (CAPS). The CAPS is a structured interview for PTSD that yields both a dichotomous (present/absent) diagnosis of PTSD and a continuous measure of PTSD severity (Blake et al., 1995). The CAPS is a widely accepted criterion measure of PTSD with good psychometric properties (Weathers, Ruscio, & Keane, 1999). A number of different scoring rules for the CAPS have been developed and evaluated (Weathers, Keane, & Davidson, 2001; Weathers et al., 1999). For this study we focused on the original scoring rule (F1/12 rule), whereby an item with a frequency score of 1 or higher and an intensity score of 2 or higher is counted as a symptom toward a PTSD diagnosis. This rule, which involves the full Diagnostic and Statistical ManualIV (DSM-IV) criteria, requires that a participant meet all three cluster criteria (B, C, and D) for a diagnosis of PTSD. That is, participants were diagnosed with PTSD if they had at least one reexperiencing symptom (Criterion B), three avoidance and numbing symptoms (Criterion C), and two hyperarousal symptoms (Criterion D). In this study the CAPS was keyed to the WTC attack, not to general trauma, and therefore it assessed current PTSD in relation with this particular traumatic event. Trauma History Questionnaire. The Trauma History Questionnaire is a 13-item measure developed to document lifetime trauma history (Green, 1993). It inquires if the participant has ever witnessed or experienced any of the following 13 traumatic events: (a) natural disasters; (b) a serious accident/injury; (c) a sudden, life-threatening illness; (d) military combat or service in
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a war zone; (e) the death of a friend/family member in an accident or by murder; (f) the sudden, unexpected death of close family member; (g) assault with a weapon; (h) assault without a weapon; (i) childhood physical abuse; (j) childhood sexual abuse; (k) unwanted sexual contact coerced by verbal threat; (l) unwanted sexual contact coerced by physical force or threat of force; or (m) any other traumatic event. For the purposes of the present study, a dichotomous variable (history of trauma yes/no) was used in the statistical analyses. This measure has been shown to have acceptable reliability and validity in clinical and nonclinical samples (Stockton, Krupnick, & Green, 2011).
The Structured Clinical Interview for the DSM-IV (SCID). The SCID is a semistructured clinical interview designed to determine DSM-IV diagnoses (First, Spitzer, Williams, & Gibbon, 1997). Its psychometric properties have been well-established, with joint interview interrater reliability kappas between .70–.94 (Skre, Onstad, Torgersen, & Kringlen, 1991). The SCID and selected modules for the DSM-IV, which included major depression, panic disorder, and generalized anxiety disorder, were administered. The WTC Exposure Questionnaire. The WTC Exposure Questionnaire was developed by a panel of trauma experts to assess occupational exposure through performance of disaster work as well as personal exposure to the WTC attacks (e.g., loss of loved ones). The development of the exposure index in this study began with variables that were shown in the disaster literature to predict PTSD and revised with questions that emerged as unique to working at the WTC site (e.g., working on the “bucket brigade”). The aspects of occupational exposure are as follows: duration of work on the site; nature of work at the site; perception of danger while working at the site; witnessing bodies, body parts, body bags, or people jumping; and feeling disturbed by the smell at the site. The aspects of personal exposure are as follows: location during the attacks; presence of a loved one in the WTC or vicinity; injury or death to a family member, friend, or colleague; attendance at funerals/memorials; and displacement from home. The Sleep Index. The Sleep Index is a modified version of the Pittsburg Sleep Quality Index (PSQI; Buysse, Reynolds, Monk, Berman, & Kupfer, 1989) and was used to assess sleep disturbances and their frequency. The PSQI has been widely used to measure sleep difficulty in different populations (Chesson et al., 2000) and has good reliability and validity (Buysse et al., 1989; Doi et al., 2000). The modified version used in this study included the following items: 1. Cannot get to sleep within 30 minutes; 2. Wake up in the middle of the night or early morning with difficulty returning to sleep; 3. Snore loudly; 4. Awake after a reasonable amount of time in bed feeling unrefreshed; 5. Had bad or disturbing dreams; 6. Had an episode of sleepwalking; 7. Had a restless, creepy-crawling sensation in legs that interfered with falling or staying asleep; 8. Doze or nap during the course of the day; 9. Taken medication prescribed or over the counter; 10. Had trouble staying awake working, driving, eating meals, or engaging in social activity. The items were coded on a 4-point Likert scale ranging from 1 (not during the past month) to 4 (three or more times a week), reflecting severity of sleep disturbance. The Cronbach alpha for these 10 items was acceptable (Cronbach alpha = .78). The items were summed to yield a total sleep disturbance score and intrinsically different sleep disturbances were also coded (insomnia, items 1, 2; sleep-disordered breathing, item 3; parasomnias with nightmares, items 5, 6, 7). Sheehan Disability Scale (SDS). The SDS is a 10-point visual analogue scale that assesses disability across three domains: work, social life, and family life (Sheehan, 1983). The three items may be summed into a single dimensional measure of global functional impairment that ranges from 0 (unimpaired) to 30 (highly impaired). This scale has been widely used and has strong internal consistency (Cronbach’s alpha = 0.89 for the three-item scale). Analytical Strategy First, the prevalence of sleep disturbances was presented for the entire sample and by PTSD status. To compare severity of sleep disturbance in participants with and without PTSD,
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Table 1 Sociodemographic Characteristics Characteristics of sample (N = 2,453) Age, M (SD) Gender
45.84 (9.5) Male Female
97.1% 2.9%
Caucasian African American Hispanic Asian Other
65.7% 18.2% 12.9% 1.1% 2.2%
Some or no high school High school graduate Some college or training College graduate More than college
2.4% 47.7% 35.6% 11.3% 3.0%
Cohabitating Separated or divorced Married Widowed Single
1.3% 9.0% 71.1% .8% 17.8%
Race
Education
Marital Status
Note. M = mean; SD = standard deviation.
independent t tests were performed on an overall sleep disturbance score as well as severity ratings for individual sleep items. To evaluate whether PTSD was significantly associated with sleep disturbance, associates of sleep disturbance among available study variables were identified by performing Pearson correlations. Variables that achieved significance at the .05-level were entered in a stepwise hierarchical regression analysis with overall sleep disturbance severity as the dependent variable. A similar approach was used to examine whether predictors differed for specific categories of sleep disturbance: insomnia, sleep-disordered breathing, and parasomnias. For both sets of analysis, sleep-related items from the CAPS (distressing dreams, item 2; difficulty of falling or staying asleep, item 13) were subtracted from the total CAPS score to address the overlap between the Sleep Index and CAPS. Moderator analysis (Baron & Kenny, 1986) was performed to assess whether the relationship between disability and sleep was moderated by PTSD status. Moderator effect was assessed by the significance of the interaction between sleep disturbance severity and PTSD status. The analyses were adjusted for past and current psychopathology and trauma history. To calculate interrater reliability, a psychologist with 10 years’ experience using the CAPS made independent ratings while observing interviews. Intraclass correlations ranged from .98–.99 for the three symptom cluster severity scores and CAPS total severity.
Results The sample primarily comprised middle-aged, White, married, male high school graduates. (See Table 1 for more details.) Of the participants, 69% reported having experienced trauma unrelated to the WTC attacks. Cukor et al. (2011) showed that the exposure variables that best predicted PTSD in this population were as follows: (a) perception of life threat, (b) knowing someone at the WTC site in the moment of the attack, (c) participating in the Bucket Brigade, (d) seeing bodies, (e) knowing
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someone who was killed in the attack, and (f) seeing body parts. With respect to WTC attack and relief work, our sample reported the following: 34.4% felt that their life was in danger; 7.6% reported saw bodies; 17.6% saw body parts; 42.2% reported knowing someone whom they expected was in WTC vicinity at the time of the attack; 43.6% reported knowing someone who was killed; and 6.2% participated in the Bucket Brigade. In terms of psychiatric history and status, 10.8% were assessed with past major depression, 6.3% with past panic disorder, and 2.4% with past generalized anxiety disorder. Of the participants, 87 (3.9%) met criteria for current major depression and 34 (1.38%) met criteria for both PTSD and depression.
Sleep Disturbance and PTSD The mean Sleep Index score was 14.23(4.85). Of the total group, 125 (5.1%) met criteria for PTSD, which is higher than the estimated 3.5% for men and women, or 1.8% for men in the general population (Kessler, Chiu, Demler, Merikangas, & Walters, 2005). The prevalence of sleep disturbance in the PTSD, non-PTSD, and the entire sample is presented in Table 2. The disturbances most often reported by the PTSD sample as happening three or more times a week were as follows: insomnia (46.3%); waking up early morning or during the night (43.8%); snoring loudly (38.7%); and feeling unrefreshed after sleep (35.0%). Table 3 shows that the PTSD group had significantly more severe sleep disturbance on every dimension measure compared to the non-PTSD group, confirming Hypothesis 1.
Association of Sleep Disturbance, Prior Trauma, Psychiatric History, and Exposure Statistically significant correlations were found between severity of sleep disturbance and the following: education and race/ethnicity (inverse), prior trauma, depression (current and past), panic (current and past), generalized anxiety disorder (current and past), and CAPS total severity score (see Table 4).
Predictors of Sleep Disturbance After controlling for demographics, prior trauma, and past and current psychopathology, the CAPS total severity score (with sleep items removed) emerged as a significant predictor of sleep disturbance, confirming Hypothesis 2 (Table 5). Regression analyses also showed that CAPS total severity score (with sleep items removed) predicts insomnia (R2 = .31, F = 37.99, β = .49, t = 18.16, p = .01), sleep-disordered breathing (R2 = .08, F = 7.68, β = .25, t = 8.02, p = .01), and parasomnias (R2 = .27, F = 31.23, β = .45, t = 16.40, p = .01).
Sleep Disturbance and Disability Bivariate correlations between the Sheehan Disability Scale and the Sleep Index suggested that people with sleep disturbance reported significantly higher disability levels (r = .58, p < .01). This relation was observed in workers both diagnosed with PTSD (r = 0.49, p < .01) and those with no diagnosis of PTSD (r = 0.49, p < .01). After controlling for demographic variables, past and current psychopathology, and trauma history, moderator regression analysis showed that the relationship between sleep disturbance and disability level is positive and significantly stronger for individuals with PTSD (interaction b = .223, standard error [SE] = .104, p < .001; Table 6).
Discussion Several important findings emerged from this study examining the complex relationship between sleep, PTSD, and disability. First, the rates of PTSD in our population exposed to WTCrelated trauma are higher (5.1%) than the 12-month PTSD prevalence in the general population, estimated at 3.5% for men and women or 1.8% for men (Kessler et al., 2005).
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Table 2 Prevalence of Sleep Disturbance Rates in the PTSD Sample, Non-PTSD Sample, and the Entire Sample
Sleep disturbance Insomnia (difficulties falling asleep within 30 minutes) Waking up early morning or during the night Snoring loudly
Feeling unrefreshed after sleep
Disturbing dreams
Sleep-walking episodes
Restless sensation in legs
Dozing or napping
Taking sleeping pills
Having trouble staying awake while working, driving, eating, or engaging in social activities
Frequency
Entire sample (n = 2,453) %
Non-PTSD sample (n = 2,198) %
PTSD sample (n = 125) %
Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week Not in the past month Less than once a week Once or twice a week Three or more times a week
68.1 11.7 11.5 8.7 65.9 14.0 12.4 7.8 59.1 10.8 11.5 18.6 62.0 16.0 13.6 8.4 79.9 12.8 5.6 1.6 98.9 .8 .2 .0 93.4 3.8 1.9 .9 55.2 18.0 15.3 11.5 93.0 2.7 2.0 2.3 85.6 7.4 4.8 2.3
70.8 12.1 10.7 6.4 69.0 14.1 11.1 5.8 60.7 10.7 11.0 17.6 64.8 16.3 11.8 7.1 83.0 11.9 4.0 1.0 99.1 .7 .2 .0 94.5 3.2 1.7 .6 56.8 18.0 14.9 10.4 93.9 2.6 1.5 2.0 87.4 6.9 4.1 1.6
19.5 7.3 26.8 46.3 9.1 10.7 36.4 43.8 24.5 16.0 20.8 38.7 9.2 15.0 40.8 35.0 23.3 30.0 33.3 13.3 95.0 3.3 1.7 0.0 73.6 14.0 6.6 5.8 29.8 15.7 22.3 32.2 77.0 4.1 9.8 9.0 51.2 17.1 17.1 14.6
Note. PTSD = posttraumatic stress disorder.
Second, those utility workers diagnosed with WTC-related PTSD as assessed by CAPS reported higher rates of nightmares, sleep-disordered breathing, and parasomnias those without PTSD. Among those not diagnosed with PTSD, the prevalence of sleep disorders is consistent with that found in the general population. For instance, the National Institutes of Health’s 2003 National Sleep Disorders Research Plan (NSDRP, 2003) estimates that anywhere between 30% and 40% of the general population suffers from insomnia. Our non-PTSD sample had a 29.2% prevalence of insomnia. Likewise, the NSDRP puts restless legs between at between 2% and
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Table 3 Sleep Disturbance Severity (Total and Individual Sleep Items) by PTSD Group No PTSD
Sleep Index total score Cannot get to sleep in 30 minutes Wake up middle night or early morning Snores loudly Feel unrefreshed Disturbing dreams Sleepwalking Restless sensation in legs Dozes or naps Took sleeping pills past month Had trouble staying awake past month
PTSD
Mean
SD
Mean
SD
t
13.79 1.53 1.54 1.85 1.61 1.23 1.01 1.08 1.79 1.12 1.20
4.44 .92 .90 1.18 .95 .57 .14 .39 1.04 .50 .58
22.15 3.00 3.15 2.74 3.02 2.37 1.07 1.45 2.57 1.51 1.95
4.81 1.15 .95 1.21 .94 .98 .31 .86 1.22 .99 1.13
−18.78** −17.00** −19.04** −7.46** −15.78** −20.36** −3.86** −9.12** −7.95** −7.84** −13.03**
Note. PTSD = posttraumatic stress disorder; M = mean; SD = standard deviation. *p < .05. **p < .01.
Table 4 Correlation Table Between Sleep Index Total Score and Demographic and Psychiatric Variables
Sleep Index
Sleep Index
Race
Education
Marital status
Age
Gender
Trauma
Past depression
Current depression
−.04*
−.05*
−.01
.03
.01
.21**
.18**
.29**
Past panic
Current panic
Past GAD
Current GAD
CAPS–total severity score (sleep items removed)
.16**
.17**
.11**
.16**
.58**
Note. GAD = general anxiety disorder; CAPS = Clinician-Administered PTSD Scale. *p < .05. **p < .01.
Table 5 Hierarchical Regression of Sleep Disturbance on CAPS Total Severity Score
Step 1
R2
F
.004
3.07
.05
22.15
.08
21.01
Education Step 2 Trauma Step 3 Past major depression Past panic disorder Past GAD Step 4
.15
.35 CAPS–total severity score (sleep items removed)
Note. CAPS = Clinician-Administered PTSD Scale. *p < .05. **p < .01.
t
−.050
−1.96*
.20
7.75**
.11 .10 .07
4.06** 3.61** 2.53**
.22 .07 .07
8.16** 2.59** 2.69**
.52
20.97**
26.40
Current major depression Current panic disorder Current GAD Step 6
β
75.32
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Table 6
Regression Analysis of Sleep Disturbance on Disability Total Score Moderated by PTSD Status∗
Step 1
R2
F
.034
15.06
.10
22.92
Trauma Step 2
.043
Past major depression Past panic disorder Past GAD Step 3
.266
.480 Sleep Index CAPS–total severity score (sleep items removed) Sleep Index* CAPS–total severity score (sleep items removed)
t 2.044*
.073 −.041 .016
3.356** −1.884 .709
.212 .011 .083
9.306** .514 3.668**
.374 .004
15.390** .038
.232
2.186*
51.06
Current major depression Current panic disorder Current GAD Step 4
β
97.56
Note. PTSD = posttraumatic stress disorder; GAD = general anxiety disorder; CAPS = ClinicianAdministered PTSD Scale. ∗ Regression analysis adjusted for demographic variables. *p < .05. **p < .01.
15%, while our non-PTSD sample reported this symptom in 5.5% of the cases. Furthermore, sleep disturbance severity was significantly higher amongst individuals with PTSD. Third, another finding that emerged from the study is that PTSD severity was significantly associated with sleep disturbance and with intrinsically different sleep disturbances. Although our study lacked objective measures of sleep disturbance, the findings as a group are consistent with mounting evidence that fear and sleep mechanisms share and interact in important ways that may account for the comorbidity of PTSD, nightmares, and sleep disordered breathing (Woodward, 2004). Last, a positive association between sleep disturbance and self-reported functional disability was found. This association was found in both the PTSD and the non-PTSD sample, but moderator analyses revealed that this association is stronger for individuals with PTSD, compared to those without PTSD.
Limitations Limitations to the current study include the cross-sectional nature of sample. As noted, sleep disturbances that are either preexisting (Gehrman et al., 2013) or develop after trauma exposure (Koren et al., 2002; Picchioni et al., 2010; Wright et al., 2011) have been linked to the development of PTSD. The cross-sectional design of this study did not permit the authors to address the causal relationship between PTSD, sleep disturbance, and disability. Moreover, the assessment of sleep impairment did not include data on whether any of the reported sleep problems developed prior to trauma exposure. Other limitations relate to the sample demographics, because this study primarily focused on White, middle-aged utility workers, and therefore the results may not generalize to other populations. Another limitation of this study is the lack of information on premorbid sleep disturbance. The constraints of the data collection process did not allow for gathering information about premorbid sleep disturbance, which may have an effect on the relationships examined in this study. Also, another limitation is the fact that sleep disturbance was assessed through a
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self-report instrument. More objective measures of sleep disturbances may shed further light on their associations with PTSD. Finally, the risk factors for sleep apnea are being male and older than 40 years of age. The sleep apnea prevalence estimate in the general population is 4% in men (Alvi & Lee, 2006), which is lower than what we have found in our sample. Some research suggests that sleep apnea may be more prevalent in trauma victims (Krakow et al., 2002). As our predominantly male sample had a mean age of 46 years, sleep apnea, which we had no way of testing, may be an unexamined variable that accounts for some of our findings. Further research needs to be done to examine the potential contribution of sleep apnea in this population.
Conclusion Despite these limitations, however, this study shows that sleep disturbance is associated with occupational and social functioning, as well as with PTSD severity. These associations suggest that ameliorating sleep may lead to increased occupational and social functioning. Furthermore, the indications that sleep disturbances are core clinical features of PTSD raise the possibility that treatment response in PTSD may be aided by sleep-focused assessments and intervention strategies. Further research is warranted to examine treatments aimed at targeting sleep disturbance and the potential role in improving functioning in work and social areas.
References Alvi, A., & Lee, S. E. (2006). Putting sleep apnea to rest: Tailored therapy reduces fatigue-related risks. Postgraduate Medicine, 119, 46–53. American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders DSM-IVTR. (4th ed.). Washington, DC: American Psychiatric Association. Babson, K. A., & Feldner, M. T. (2010). Temporal Relations between sleep problems and both traumatic event exposure and PTSD: A critical review of the empirical literature. Journal of Anxiety Disorders, 24, 1–15. doi:10.1016/j.janxdis.2009.08.002 Baron, R. M., & Kenny, D. A. (1986). The moderator-mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51, 1173–1182. doi:10.1037/0022-3514.51.6.1173 Beck, A. T., Steer, R. A., & Brown, G. K. (1996). Manual for the Beck Depression Inventory. San Antonio, TX: The Psychological Corporation. Blake, D. D., Weathers, F. W., Nagy, L. M., Kaloupek, D. G., Gusman, F. D., Charney, D. S., et al. (1995). The development of a clinician-administered PTSD scale. Journal of Traumatic Stress, 8, 75–90. doi:10.1002/jts.2490080106 Buysse, D. J., Reynolds, C. F., Monk, T. H., Berman, S. R., & Kupfer, D. J. (1989). The Pittsburgh Sleep Quality Index: A new instrument for psychiatric practice and research. Psychiatry Research, 28, 193–213. doi:10.1016/0165-1781(89)90047-4 Chesson, A., Hartse, K., Anderson, W. M., Davila, D., Johnson, S., Littner, M., & et al. (2000). Practice parameters for the evaluation of chronic insomnia: An American Academy of Sleep Medicine Report. Standards of Practice Committee of the American Academy of Sleep Medicine. Sleep, 23, 237–241. Cukor, J., Wyka, K., Jayasinghe, N., Weathers, F., Giosan, C., Leck, P., . . . Difede, J. (2011). Prevalence and predictors of posttraumatic stress symptoms in utility workers deployed to the World Trade Center following the attacks of September 11, 2001. Depression and Anxiety, 28, 210–217. doi:10.1002/da.20776 DeViva, J. C., Zayfert, C., Pigeon, W. R., & Mellman, T. A. (2005). Treatment of residual insomnia after CBT for PTSD: Case studies. Journal of Traumatic Stress, 18, 155–159. doi:10.1002/jts.20015 Difede, J., Roberts, J., Jayasinghe, N., & Leck, P. (2006). Evaluation and treatment of firefighters and utility workers following the World Trade Center attacks. In Y. Neria, R. Marshall, & E. Susser (Eds.), Mental health in the wake of terrorist attacks. New York: Cambridge University Press. Retrieved from http://dx.doi.org/10.1017/CBO9780511544132.022 Doi, Y., Minowa, M., Uchiyama, M., Okawa, M., Kim, K., Shimui, K., & et al. (2000). Psychometric assessment of subjective sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects. Psychiatry Research, 97, 165–172.
82
Journal of Clinical Psychology, January 2015
First, M. B., Spitzer, R. L., Williams, J. B. W., & Gibbon, M. (1997). Structured clinical interview for DSM-IV SCID. Washington, DC: American Psychological Association. Galovski, T. E., Monson, C., Bruce, S. R., & Resick, P. A. (2009). Does cognitive-behavioral therapy for PTSD improve perceived health and sleep impairment? Journal of Traumatic Stress, 22, 197–204. doi:10.1002/jts.20418 Gehrman, P., Seelig, A. D., Jacobson, I. G., Boyko, E. J., Hooper, T. I., Gacksetter, G. D., . . . for the Millenium COhort Study Team. (2013). Predeployment sleep duration and insomnia symptoms as risk factors for new-onset mental health disorders following military deployment. Sleep, 36, 1009–1018. Gellis, L. A., & Gerhman, P. R. (2011). Cognitive behavioral treatment for insomnia in veterans with longstanding posttraumatic stress disorder: a pilot study. Journal of Aggression, Maltreatment & Trauma, 20, 904–916. Germain, A., Buysse, D. J., & Nofzinger, E. (2011). Sleep–specific mechanisms underlying posttraumatic stress disorder: Integrative review and neurobiological hypotheses. Sleep Medicine Reviews, 12, 185–195. doi:10.1016/j.smrv.2007.09.003 Germain, A., Shear, M. K., Hall, M., & Buysse, D. J. (2007). Effects of a brief behavioral treatment for PTSD-related sleep disturbances: A pilot study. Journal of Behavior Research and Therapy, 45, 627–632. doi:10.1016/j.brat.2006.04.009 Goldstein, G., van Kammen, W., Shelly, C., Miller, D. J., & van Kammen, D. P. (1987). Survivors of imprisonment in the Pacific Theater during World War II. American Journal of Psychiatry, 144, 1210– 1213. Green, B. L. (1993). Trauma History Questionnaire. In Instrumentation in Stress, Trauma and Adaptation (pp. 366–369). Northbrook, IL: Research and Methodology Interest Group of the ISTSS. Inman, D. J., Silver, S. M., & Doghramji, K. (1990). Sleep disturbance in post-traumatic stress disorder: A comparison with non-PTSD insomnia. Journal of Traumatic Stress, 3, 429–437. doi:10.1002/jts.2490030311 Kato, H., Asukai, N., Miyake, Y., Minakawa, K., & Nishiyama, A. (1996). Post-traumatic symptoms among younger and elderly evacuees in the early stages following the 1995 Hanshin-Awaji earthquake in Japan. Acta Psychiatrica Scandinavica, 93, 477–481. doi:10.1111/j.1600-0447.1996.tb10680.x Kessler, R. C., Chiu, W. T., Demler, O., Merikangas, K. R., & Walters, E. E. (2005). Prevalence, severity, and comorbidity of 12-month DSM-IV disorders in the National Comorbidity Survey Replication. Archives of General Psychiatry, 62, 617–627. doi:10.1001/archpsyc.62.6.617 Kilpatrick, D., Resnick, H., Freedy, J., Pelcovitz, D., Resick, P., Roth, S., & et al. (1998). Posttraumatic stress disorder field trial: Evaluation of the PTSD construct-criteria A through E. In T. A. Widiger, A. J. Frances, H. A. Pincus, R. Ross, M. B. First, W. Davis, & M. Kline (Eds.), DSM-IV Sourcebook. Washington, DC: American Psychiatric Press. Koren, D., Arnon, I., Lavie, P., & Klein, E. (2002). Sleep complaints as early predictors of posttraumatic stress disorder: A 1 year prospective study of injured survivors of motor vehicle accidents. American Journal of Psychiatry, 159, 855–857. doi:10.1176/appi.ajp.159.5.855 Krakow, B., Artar, A., Warner, T. D., Melendrez, D., Johnston, L., Hollifield, M., & et al. (2000). Sleep disorder, depression, and suicidality in female sexual assault survivors. Crisis, 21, 163–170. Krakow, B., Hollifield, M., Johnston, L., Koss, M., Shrader, R., Warner, T. D., & et al. (2001). A randomized controlled study of imagery rehearsal therapy for chronic nightmares in sexual assault survivors with posttraumatic stress disorder. JAMA, 286, 537–545. doi:10.1023/A:1007854015481 Krakow, B., Melenderez, D., Johnston, L., Warner, T., Clark, J., Pacheco, M., & et al. (2002). Sleepdisordered breathing, psychiatric distress and quality of life impairment in sexual assault survivors. Journal of Nervous Mental Health Disease, 190, 442–452. Krakow, B., Melendrez, D., Pedersen, B., Johnston, L., Hollifield, M., Germain, A., . . . Schrader, R. (2001). Complex insomnia: Insomnia and sleep-disordered breathing in a consecutive series of crime victims with nightmares and PTSD. Biological Psychiatry, 49, 948–953. doi:10.1097/00005053-200207000-00004 Kuch, K., & Cox, B. J. (1992). Symptoms of PTSD in 124 survivors of the holocaust. American Journal of Psychiatry, 149, 337–340. Lamarche, L. J., & De Koninck, J. (2007). Sleep disturbances in patients with post- traumatic stress disorder epidemiology, impact and approaches to management. Journal of Clinical Psychiatry, 68, 1257–1270. doi:http://dx.doi.org/10.4088/JCP.v68n0813 Lavie, P., & Hertz, G. (1979). Increased sleep motility and respiration rates in combat neurotic patients. Biological Psychiatry, 14, 983–987.
Sleep Disturbance, PTSD, and Disability
83
Leskin, G., Woodward, S. H., Young, H., & Sheikh, J. I. (2002). Effects of comorbid diagnoses on sleep disturbance in PTSD. Psychiatric Research, 36, 449–452. doi:10.1016/S0022-3956(02)00025-0 MacLay, R. N., Klam, W. P., & Volkert, S. L. (2010). Insomnia is the most commonly reported symptom and predicts other symptoms of post-traumatic stress disorder in U.S. service members returning from military deployments. Military Medicine, 175, 759–762. Maher, M. J., Rego, S. A., & Asnis, G. M. (2006). Sleep disturbances in patients with post- traumatic stress disorder: Epidemiology, impact and approaches to management. CNS Drugs, 20, 567–590. doi:10.2165/00023210-200620070-00003 Manber, R., Edinger, J. D., Gress, J. L., San Pedro-Salcedo, M. G., Kuo, T. F., & Kalista, T. (2008). Cognitive behavioral therapy for insomnia enhances depression outcome in patients with comorbid major depressive disorder and insomnia. Sleep, 31, 489–495. doi:10.1001/archpsyc.65.5.551 Margolies, S. O., Rybarczyk, B., Vrana, S. R., Leszczyszyn, D. J., & Lynch, J. (2013). Efficacy of a cognitivebehavioral treatment for insomnia and nightmares in Afghanistan and Iraq veterans with PTSD. Journal of Clinical Psychology, 69, 1026–1042. doi:10.1002/jclp.2197 Mellman, T. A. (2008). Sleep and post-traumatic stress disorder: A roadmap for clinicians and researchers. Sleep Medicine Reviews, 12, 165–167. Mellman, T. A., David, D., Kulick-Bell, R., Hebding, J., & Nolan, B. (1995). Sleep disturbance and its relationship to psychiatric morbidity after Hurricane Andrew. American Journal of Psychiatry, 152, 1659–1663. National Sleep Disorders Research Plan. (2003). 2003 National Sleep Disorders Research Plan. Retrieved from http://www.nhlbi.nih.gov/health/prof/sleep/res_plan/sleep-rplan.pdf Neylan, T. C. (2013). Sleep and psychological vulnerability to traumatic stress. Commentary on Gehrman et al. Predeployment sleep duration and insomnia symptoms as risk factors for new-onset mental health disorders following military deployment. Sleep, 36, 1009–1018. Neylan, T. C., Marmar, C. R., Metzler, T. J., Weiss, D. S., Zatzick, D. F., Delucchi, K. L., & et al. (1998). Sleep disturbances in the Vietnam generation: findings from a nationally representative sample of male Vietnam veterans. American Journal of Psychiatry, 155, 929–933. North, C. S., Nixon, S., Shariat, S., Mallonee, S., McMillen, J. C., Spitznagel, E. L., & et al. (1999). Psychiatric disorders among survivors of the Oklahoma City bombing. Journal of the American Medical Association, 282, 755–762. Ohayon, M. M., & Shapiro, C. M. (2000). Sleep disturbances in psychiatric disorders associated with posttraumatic stress disorder in the general population. Comprehensive Psychiatry, 41, 469–478. doi:http://dx.doi.org/10.1053/comp.2000.16568 Pace-Schott, E. F., MIlad, M. R., Orr, S. P., Rauch, S. L., Stickgold, R., & Pitman, R. K. (2009). Sleep promotes generalization of extinction of conditioned fear. Sleep, 32, 19–26. Perlman, L. M., Arnedt, J. T., Earnheart, K. L., Gorman, A. A., & Shirley, K. G. (2008). Group cognitive behavioral therapy for insomnia in a VA mental health clinic. Cognitive and Behavioral Practice, 15, 426–434. doi:10.1016/j.cbpra.2008.05.003 Picchioni, D., Cabrera, O. A., McGurk, D., Thomas, J. L., Castro, C. A., Balkin, T. J., . . . Hoge, C. W. (2010). Sleep symptoms as partial mediator between combat stressors and other mental health symptoms in Iraq War veterans. Military Psychology, 22, 340–355. Pillar, G., Malhotra, A., & Lavie, P. (2000). Post-traumatic stress disorder and sleep–What a nightmare! Sleep Medicine Reviews, 4, 183–200. doi:10.1053/smrv.1999.0095 Ross, R. J., Ball, W. A., Sullivan, K. A., & Caroff, S. N. (1989). Sleep disturbances, the hallmark of posttraumatic stress disorder. American Journal of Psychiatry, 146, 1179–1196. Sheehan, D. V. (1983). The anxiety disease. New York: Scribner’s. Skre, I., Onstad, S., Torgersen, S., & Kringlen, E. (1991). High interrater reliability for the Structured Clinical Interview for DSM-III-R Axis I (SCID-I). Acta Psychiatrica Scandinavica, 84(2), 167–173. Spoormaker, V. I., & Montgomery, P. (2008). Disturbed sleep in post-traumatic stress disorder: Secondary symptom or core feature? Sleep Medicine Reviews, 12, 169–184. doi:10.1016/j.smrv.2007.08.008 Stein, M. B. (2002). A 46-year-old man with anxiety and nightmares after a motor vehicle collision. JAMA, 288, 1513. doi:10.1001/jama.288.12.1513 Stockton, P., Krupnick, J. L., & Green, B. L. (2011). Development, use, and psychometric properties of the Trauma History Questionnaire. Journal of Loss and Trauma, 16, 258–283. Ulmer, C. S., Edinger, J. D., & Calhoun, P. S. (2011). A multi-component cognitive behavioral intervention for sleep disturbance in veterans with PTSD: A pilot study. Journal of Clinical Sleep Medicine, 7, 57–68.
84
Journal of Clinical Psychology, January 2015
Van der Helm, E., & Walker, M. P. (2011). Sleep and emotional memory processing. Sleep Medicine Clinics, 6, 31–43. doi:10.1016/j.jsmc.2010.12.010 Van Liempt, S., van Zuiden, M., Westenberg, H., Super, A., & Vermetten, E. (2013). Impact of impaired sleep on the development of PTSD symptoms in combat veterans: A prospective longitudinal cohort study. Depression and Anxiety, 30, 469–474. doi:10.1002/da.22054 Weathers, F. W., Keane, T. M., & Davidson, J. (2001). Clinician-Administered PTSD Scale: A review of the first ten years of research. Depression and Anxiety, 13, 132–156. doi:10.1002/da.1029 Weathers, F. W., Ruscio, A. M., & Keane, T. M. (1999). Psychometric properties of nine scoring rules for the Clinician-Administered Posttraumatic Stress Disorder Scale. Psychological Assessment, 11, 124–133. doi:10.1037/1040-3590.11.2.124 Woodward, S. (2004). PTSD sleep research: An update. PTSD Research Quarterly, 15, 1–8. Wright, K. M., Britt, T. W., Bliese, P. D., Adler, A. B., Picchioni, D., & Moore, D. (2011). Insomnia as predictor versus outcome of PTSD and depression among Iraq combat veterans. Journal of Clinical Psychology, 67, 1240–1258. doi:10.1002/jclp.20845 Zayfert, C., & Deviva, J. C. (2004). Residual insomnia following cognitive behavioral therapy for PTSD. Journal of Traumatic Stress, 17, 69–73.
