An Initial Investigation of the Relationship Between Insomnia and Hoarding Amanda M. Raines, Amberly K. Portero, Amanda S. Unruh, Nicole A. Short, and Norman B. Schmidt Florida State University
Objective: Insomnia has been shown to have profound negative consequences on multiple aspects of daily functioning. Despite increased interest in the association between insomnia and psychopathology, no research has examined the relationships between insomnia and hoarding. The aim of the current investigation was to examine the associations between insomnia and hoarding severity. Methods: Participants consisted of patients with hoarding disorder (n = 24). Results: Results revealed that insomnia was a significant predictor of increased hoarding severity. In addition, when examining the relationships among insomnia and specific hoarding symptoms, sleep difficulties were associated with increased acquiring and difficulty discarding behaviors. Conclusions: These findings add to a growing body of literature on insomnia and various forms of psychopathology, as well as research on symptoms related to hoarding. Reducing insomnia symptoms among hoarders may help C 2015 Wiley Periodicals, Inc. to reduce hoarding-related behaviors and increase treatment efficacy. J. Clin. Psychol. 71:707–714, 2015. Keywords: hoarding; insomnia; sleep difficulties; acquiring; discarding
Sleep difficulties are a common source of distress among the general population. Research indicates that sleep difficulties are more prevalent than heart disease, cancer, diabetes, and AIDS (Lichstein, Durrence, Riedel, Taylor, & Bush, 2004), with about a third of the population experiencing sleep issues such as trouble falling asleep or waking too early (Breslau, Roth, Rosenthal, & Andreski, 1996), and 9% to 12% of the population reporting a clinically significant insomnia condition (Ford & Kamerow, 1989; Gallup Organization, 1991). Insomnia-related problems (both direct and indirect) cost an estimated $107 billion dollars annually, with the majority of cost attributed to insomnia-related absence from work, reduced productivity at work, and motor vehicle accidents (Rosekind & Gregory, 2010). In addition, insomnia is highly comorbid with several common and costly medical conditions including heart disease, high blood pressure, and diabetes, leading to increased healthcare service utilization (Rosekind & Gregory, 2010; Taylor et al., 2007). The negative effects of insomnia are further evidenced by the associations between sleep difficulties and various psychiatric conditions. Specifically, rates of comorbidity between insomnia and psychiatric disorders often range from 40% to 50% among both community and clinical samples (Harvey, 2001; Ohayon & Roth, 2003), with elevated insomnia symptoms frequently associated with increased alcohol abuse, drug abuse, and depression and mood disorders (Ohayon & Roth, 2003). Additionally, studies indicate that self-reported sleep problems may be a prodromal symptom of a first depressive episode (Perlis, Giles, Buysse, Tu, & Kupfer, 1997) and that nondepressed individuals with insomnia are twice as likely to develop depression as compared to individuals with no sleep problems (Baglioni et al., 2011). Insomnia has also been linked to numerous anxiety-related conditions. For example, research suggests that of all the anxiety disorders, generalized anxiety disorder (GAD) has the greatest comorbidity rate with insomnia (Monti & Monti, 2000), with the majority of individuals with GAD reporting that disturbances in sleep interfere with their overall functioning and daily
Please address correspondence to: Norman B. Schmidt, Department of Psychology, Florida State University, 1107 W. Call St., Tallahassee, FL 32306-4301. E-mail: [email protected] JOURNAL OF CLINICAL PSYCHOLOGY, Vol. 71(7), 707–714 (2015) Published online in Wiley Online Library (wileyonlinelibrary.com/journal/jclp).
C 2015 Wiley Periodicals, Inc. DOI: 10.1002/jclp.22161
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activities (B´elanger, Morin, Langlois, & Ladouceur, 2004). Sleep disturbances are also prevalent among individuals with obsessive-compulsive disorder (OCD). Paterson, Reynolds, Ferguson, and Dawson (2013) conducted a systematic literature review on insomnia in OCD and found that individuals with OCD often exhibited delayed onset of sleep, with more severe OCD associated with increased sleep disturbances. In addition to GAD and OCD, insomnia-related problems are also prevalent among individuals with specific phobia, panic disorder, and posttraumatic stress disorder (PTSD; Lamarche & De Koninck, 2007; Ohayon, 1997). Although a positive association between insomnia and numerous anxiety-related conditions has been firmly established, the relationship between insomnia and hoarding has yet to be examined. Hoarding disorder is a complex clinical phenomenon characterized by an accumulation of and failure to discard a large number of possessions resulting in debilitating clutter (Frost & Hartl, 1996). Once thought to be a rather rare condition, hoarding is now estimated to affect between 2% and 6% of the population (American Psychiatric Association [APA], 2013). In its most severe states, hoarding can cause significant health problems due to unsanitary conditions, social withdrawal, work disability, and even death (Frost, Steketee, & Williams, 2000; Kim, Steketee, & Frost, 2001). Hoarding has been observed in a number of psychiatric conditions including social phobia, depression, and personality disorders (Frost, Steketee, & Tolin, 2011; Frost, Steketee, Williams, & Warren, 2000) but was initially thought to be a variant of OCD. Whereas there is little doubt that hoarding can occur in the context of obsessive- and compulsive-related symptoms (Pertusa et al., 2008), there is an increasing body of data indicating distinct developmental trajectories (Samuels et al., 2002), diagnostic features (Pertusa et al., 2010), and patterns of comorbidity (Pertusa et al., 2008). In light of this accumulating evidence, hoarding disorder has been included as a discrete diagnostic entity within the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5; APA, 2013). Despite the lack of information regarding sleep difficulties among hoarding populations, it is reasonable to assume that hoarders may be at increased risk for insomnia. One aspect of hoarding in particular that may be contributing to sleep difficulties is clutter. Over the last decade, clutter has been identified as a cardinal feature of hoarding disorder and a core source of functional impairment. For instance, in their initial definition of hoarding, Frost and Hartl (1996) posit that clinically significant hoarding cannot occur in the absence of clutter. Further, they state that the majority of impairment associated with hoarding is a direct result of the influence that clutter has on an individual’s life. This impairment includes but is not limited to an inability to perform activities of daily living such as preparing food, maintaining hygiene, and sleeping (Frost & Hartl, 1996). For example, among a statewide survey of various health departments, Frost, Steketee, and Williams (2000) found that in approximately 90% of cases, clutter prevented individuals from accessing basic furniture. Given that clutter often precludes one from using their living spaces for their intended purpose, hoarders are often forced to complete activities of daily living (eating, sleeping, etc.) in one small space. Considering that all these activities are taking place in the same area in which they are likely sleeping, hoarders could be at risk for poor sleep hygiene, which would contribute to symptoms of insomnia (Bootzin & Epstein, 2011). This conceptualization is consistent with the stimulus dyscontrol model of insomnia in which cues not associated with sleep (e.g., items associated with daytime activities such as television, food, work) in the sleeping area may interfere with sleep promoting processes (Bootzin, 1973). When coupled with the high prevalence rates of insomnia symptoms among other anxiety-related conditions (Monti & Monti, 2000; Ohayon, 1997; Paterson et al., 2013), this points to a potential relationship between hoarding and symptoms of insomnia. To our knowledge, no research to date has explored the associations between insomnia and hoarding severity. The current study sought to examine the associations between insomnia and hoarding in a sample of individuals with hoarding disorder. Based on the extant literature establishing an association between insomnia and various forms of psychopathology, we hypothesized that symptoms of insomnia would be associated with increased hoarding severity, even after controlling for mood and PTSD diagnoses, which have both been found to be highly comorbid with hoarding and insomnia (Frost et al., 2011; Harvey, Jones, & Schmidt, 2003). In
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addition, we examined the associations among insomnia and specific hoarding symptoms (i.e., acquiring, difficulty discarding, and clutter). Given the considerable impairment associated with clutter and the likelihood of poor sleep hygiene among this population, it was hypothesized that symptoms of insomnia would be most associated with the clutter component of hoarding.
Methods Participants A total of 24 individuals with hoarding disorder participated in the current study. To be eligible for inclusion, participants had to be 18 years of age or older, be English speakers, and have a diagnosis of hoarding as determined by the Structured Interview for Hoarding Disorder (SIHD; Pertusa & Mataix-Cols, 2011). In addition to a diagnosis of hoarding, 54.2% of the sample met for a current anxiety diagnosis, 50% met for a current mood diagnosis, 25% met for current PTSD, 4.2% met for current OCD, 4.2% met for a current substance use disorder, and 4.2% met for an eating disorder. The sample was primarily female (87.5%), ranging from 18 to 63 years of age (mean [M] = 41.67, standard deviation [SD] = 15.18). Participant’s race was distributed as such: 62.5% Caucasian and 37.5% African American. Approximately 58% of the sample was single, 8.3% married, 20.8% divorced or separated, 8.3% cohabitating, and 4.2% widowed.
Procedure Participants in the current study were recruited from the community and an outpatient anxiety disorders clinic to participate in a research study examining environmental influences on hoarding behaviors. Upon arrival to the laboratory, informed consent was obtained. Next participants completed the Mini International Neuropsychiatric Interview (MINI; Sheehan et al., 1998), a battery of self-report questionnaires, and several study-specific tasks. After completing all tasks, participants were debriefed, thanked for their time, and compensated $20 cash for their participation. All procedures were approved by the university’s institutional review board.
Measures–Clinician Administered PTSD and Major Depressive Disorder (MDD). Diagnoses of PTSD and mood disorders were assessed using the MINI (Sheehan et al., 1998). The MINI is a brief structured clinical interview for DSM-IV and International Classification of Diseases Tenth Revision (ICD-10) psychiatric disorders. A highly trained, doctoral-level clinical psychology graduate student, who was advised by a licensed clinical psychologist to ensure accurate diagnosis, administered the MINI. The MINI is compatible with international diagnostic criteria, including the DSM-IV (Sheehan et al., 1998). Hoarding. Hoarding was assessed using the SIHD (Pertusa & Mataix-Cols, 2011). The SIHD is a structured interview that was developed based on the provisional criteria for hoarding disorder diagnosis before completion of the DSM-5. The interview contains detailed questions regarding each of the six criteria for hoarding disorder. Measures–Self-Report Hoarding. Hoarding behaviors were assessed using the Saving Inventory-Revised (SIR; Frost, Steketee, & Grisham, 2004). The SIR is a 23-item self-report questionnaire that assesses hoarding behaviors, including acquiring, clutter, and difficulty discarding (Frost et al., 2004). Participants rate each item using a 5-point Likert scale ranging from 0 to 4, with higher scores indicating increased frequency and severity of hoarding behaviors. The SIR has demonstrated strong internal consistency as well as good test-retest reliability (Coles, Frost, Heimberg, & Steketee, 2003; Frost et al., 2004). The SIR demonstrated good internal consistency in the
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Table 1 Zero-Order Correlations, Means, and Standard Deviations
1. ISI 2. SIR 3. SIR-C 4. SIR-A 5. SIR-D
1
2
– .46* .24 .48* .36
– .74*** .91*** .76***
3
– .50* .27
4
– .64**
5
Mean
SD
–
14.88 58.42 23.26 15.78 19.39
5.09 12.12 5.05 6.09 4.13
Note. SD = standard deviation; ISI = Insomnia Severity Index–Total Score; SIR = Saving Inventory Revised –Total Score; SIR-C = Saving Inventory Revised-Clutter Subscale; SIR-A = Saving Inventory Revised–Acquiring Subscale; SIR-D = Saving Inventory Revised–Discarding Subscale. ***p < .001. **p < .01. *p < .05.
present investigation (α = .90). Additionally, the discarding, clutter, and acquisitioning subscales demonstrated adequate internal consistency (alphas ranged from .80 to 86).
Insomnia. Symptoms of insomnia were assessed using the Insomnia Severity Index (ISI; Bastien, Valli`eres, & Morin, 2001). The ISI is a brief seven-item self-report questionnaire assessing sleep difficulties (e.g., falling asleep, staying asleep, waking too early), satisfaction/dissatisfaction with sleep patterns, and/or interference with daily functioning. Respondents were asked to rate each item using a 5-point Likert scale ranging from 0 to 4, with higher scores reflecting more severe sleep problems. The ISI has shown evidence of high internal consistency (Bastien et al., 2001). The ISI demonstrated adequate internal consistency in the present investigation (α = .74). Results Preliminary Analyses The means, standard deviations, and zero-order correlations for all self-report measures used in the current analyses can be found in Table 1. The mean SIR score was comparable to that found in other reports using hoarding disorder populations (Timpano & Schmidt, 2012). Additionally, the mean ISI score was slightly higher than that reported in other clinical populations, suggesting that our sample was elevated on insomnia symptoms (Raffray, Bond, & Pelissolo, 2011). In line with initial predictions, symptoms of insomnia were significantly correlated with hoarding severity (r = .46). Inconsistent with prediction, however, insomnia severity was not correlated with the clutter domain of hoarding (r = .24), but rather it was associated only with the acquiring subfactor (r = .48). Regarding insomnia severity, 12.5% of the sample scored in the nonclinical range, 37.5% scored in the subthreshold range, and 50% scored in the clinically significant range.
Primary Analyses A hierarchical regression equation was computed to examine the association between sleep disturbances (using the ISI) and hoarding severity (using the SIR). Preliminary analyses indicated that there were no threats or violations of normality, multicollinearity, or homoscedasticity. In the first step of the model, the presence of a mood diagnosis (as measured by the MINI), as well as the presence of PTSD (as measured by the MINI), was entered accounting for 14.4% of the variance in hoarding severity, F(2, 21) = 1.77, p = .20. In the second step of the model, ISI total scores were added accounting for an additional 27% of the variance (F-change = 9.21, p = .007) in hoarding severity. Results revealed that insomnia severity was significantly associated with
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hoarding severity (β = .53, t = 3.04, p = .007, sr2 = .27) above and beyond mood and PTSD diagnoses.1 Next a series of hierarchical regression analyses were performed to examine the relationships among sleep disturbances and specific hoarding symptoms (i.e., acquiring, difficulty discarding, and clutter) after controlling for the presence of a mood diagnosis and PTSD. Once again, preliminary analyses indicated no threats or violations of normality, multicollinearity, or homoscedasticity. For each regression equation, the presence of a mood or PTSD diagnosis was entered into the first step of the model. In the second step, ISI total scores were added. Results revealed that the acquiring (β = .54, t = 3.06, p = .007, sr2 = .28) and difficulty discarding (β = .46, t = 2.69, p = .014, sr2 = .20) subscales of the SIR were significantly associated with increased insomnia symptoms, whereas the clutter subscale was not (β = .28, t = 1.23, p = .23, sr2 = .07).
Discussion Results indicated that insomnia was associated with increased hoarding severity even after controlling for relevant covariates. These results are consistent with initial prediction and support previous research demonstrating associations between symptoms of insomnia and psychopathology (B´elanger et al., 2004; Craske & Rowe, 1997; Stein, Kroft, & Walker, 1993). When examining the associations between specific hoarding facets (i.e., acquiring, difficulty discarding, and clutter) and sleep disturbances, results revealed that symptoms of insomnia were associated with the excessive acquiring and difficulty discarding domains of hoarding. While unanticipated, these findings are consistent with research demonstrating that sleep disturbances are associated with increased reward motivated behaviors and blunted activity in decisionmaking regions of the brain. For example, research has demonstrated that sleep deprivation can enhance activity within the striatum and amygdala, two reward sensitive regions of the brain (Benedict et al., 2012). This overactivity appears to trigger a state in which rewards are overvalued and losses are undervalued (Goldstein & Walker, 2014). It has been suggested that acquiring behaviors, much like impulse control disorders, are driven by positive emotional states and reward motivated behaviors (Steketee & Frost, 2003). Moreover, when making decisions regarding whether to keep or discard a possession, hoarders have been found to display excessive hemodynamic activity in the orbital frontal cortex, a region of the brain that is associated with processing relative reward value (Tolin, Kiehl, Worhunsky, Book, & Maltby, 2009). Given that sleep difficulties affect one’s decision-making abilities, it is reasonable to assume that symptoms of insomnia may be one factor contributing to the excessive acquiring and difficulty discarding symptoms of hoarding. Inconsistent with initial predictions, we did not find a significant association between symptoms of insomnia and the clutter domain of hoarding. Although unanticipated, it is possible that clutter is more associated with other aspects of sleep apart from insomnia. Indeed, insomnia, which involves a difficulty initiating sleep, maintaining sleep, or waking up too early (Edinger et al., 2004), is just one type of sleep problem. Previous research has indicated that other aspects of sleep difficulties including sleep quality, sleep duration, circadian rhythm disturbances, nightmares, or daytime dysfunction may also be associated with mental health problems (Asarnow, Soehner, & Harvey, 2013; Germain, 2013). Thus, it is possible that clutter is associated with impaired sleep quality or shorter sleep duration constructs, which are not assessed in our measure of insomnia (i.e., ISI). Future research should continue to investigate the relations between insomnia, sleep quality, and other types of sleep disturbances among hoarding populations. Taken together, these findings have important implications for the larger framework of Frost and Hartl’s (1996) cognitive behavioral model of hoarding. According to this model, hoarding 1 To ensure that the relationship between insomnia and hoarding was not due to co-occuring anxiety disorder
diagnoses, separate regression equations were computed controlling for mood, PTSD, and anxiety disorder diagnoses. Results remained significant.
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is a multifaceted problem stemming from various information processing deficits in the areas of attention, decision making, and memory. For example, hoarders frequently shift their attention from one object to another, causing an inability to make decisions or follow through with decisions during tasks such as discarding (Frost & Gross, 1993). Additionally, hoarders doubt their ability to remember information. Saving items is a way of retaining this information without having to actually remember it (Frost & Steketee, 1998). Given that individuals with insomnia often complain of attention, concentration, and memory impairment (for review, see Bootzin and Epstein, 2011), sleep-related problems may be one factor contributing to the information processing deficits seen among hoarders; that is, sleep-related problems may create a vicious cycle in which the cognitive deficits observed among hoarders are continuously perpetuated by a lack of sleep. Results of the present study suggest insomnia may be an important but often overlooked factor that affects the symptoms of hoarding disorder. In terms of clinical implications, clinicians should inquire about symptoms of insomnia among hoarding disorder patients and the degree to which these symptoms affect specific hoarding behaviors to determine if interventions are needed. Indeed, treating insomnia through interventions such as cognitive behavioral therapy for insomnia (CBT-I) has been shown to improve co-occurring symptoms of anxiety disorders in a number of studies (Belleville, Cousineau, Levrier, & St-Pierre-Delorme, 2011). Additionally, treatment of insomnia leads to enhanced treatment outcomes for mood disorders such as depression (Manber et al., 2008). Considering this previous research as well as the current findings, it raises the question of whether targeting insomnia among individuals with hoarding disorder could lead to overall symptom improvement and enhanced treatment outcomes.
Limitations The current study should be considered in the context of its limitations. First, due to the cross-sectional design of the study, causal inferences cannot be made. Although it is likely that impairments in emotion regulation and cognitive functioning due to sleep loss affect the symptoms of hoarding disorder, particularly acquiring and difficulty discarding, it is also possible that symptoms of hoarding (i.e., clutter obstructing one’s sleeping area) may increase symptoms of insomnia, or that a bidirectional relationship exists between the two (Harvey, 2011). Future research should employ experimental and prospective designs to determine the causal nature of this association. In addition, although we used a well-validated measure of insomnia (Bastien et al., 2001) that has demonstrated associations with objective measures of sleep (i.e., polysomnographic evaluation), we did rely on self-reported symptoms of insomnia. Future studies could index insomnia through objective methods such as actigraphy and polysomnography to strengthen these findings. Finally, our sample size was relatively small, and future research should attempt to replicate these findings in larger samples of individuals with hoarding disorder.
Conclusion Despite these limitations, the current investigation provides important information regarding the relationship between insomnia and hoarding. To our knowledge, this investigation is the first to examine the relationship between these two constructs. It appears that insomnia is a robust, significant predictor of increased hoarding severity, specifically acquiring and difficulty discarding. This association was particularly strong, with symptoms of insomnia uniquely accounting for 28% of the total variance in hoarding severity. Considering the lack of information on risk factors for hoarding, these findings add considerably to the growing body literature on hoarding disorder and insomnia within various anxiety-related conditions.
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Harvey, A. G., Jones, C., & Schmidt, D. A. (2003). Sleep and posttraumatic stress disorder: A review. Clinical Psychology Review, 23(3), 377–407. Kim, H., Steketee, G., & Frost, R. (2001). Hoarding by elderly people. Health and Social Work, 26(3), 176–184. Lamarche, L. J., & De Koninck, J. (2007). Sleep disturbance in adults with posttraumatic stress disorder: A review. Journal of Clinical Psychiatry. Lichstein, K. L., Durrence, H. H., Riedel, B. W., Taylor, D. J., & Bush, A. J. (2004). Epidemiology of sleep: Age, gender, and ethnicity: Psychology Press. 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(4), 489. Monti, J. M., & Monti, D. (2000). Sleep disturbance in generalized anxiety disorder and its treatment. Sleep Medicine Reviews, 4(3), 263–276. Ohayon, M. M. (1997). Prevalence of DSM-IV diagnostic criteria of insomnia: distinguishing insomnia related to mental disorders from sleep disorders. Journal of Psychiatric Research, 31(3), 333–346. Ohayon, M. M., & Roth, T. (2003). Place of chronic insomnia in the course of depressive and anxiety disorders. Journal of Psychiatric Research, 37(1), 9–15. Paterson, J. L., Reynolds, A. C., Ferguson, S. A., & Dawson, D. (2013). Sleep and obsessive-compulsive disorder (OCD). Sleep Medicine Reviews, 17(6), 465–474. Perlis, M. L., Giles, D. E., Buysse, D. J., Tu, X., & Kupfer, D. J. (1997). Self-reported sleep disturbance as a prodromal symptom in recurrent depression. Journal of Affective Disorders, 42(2), 209–212. Pertusa, A., Frost, R., Fullana, M., Samuels, J., Steketee, G., Tolin, D. F., . . . Mataix-Cols, D. (2010). Refining the diagnostic boundaries of compulsive hoarding: a critical review. Clinical Psychology Review, 30(4), 371–386. Pertusa, A., Fullana, M.A., Singh, S., Alonso, P., Menchon, J. M., & Mataix-Cols, D. (2008). Compulsive Hoarding: OCD Symptom, Distinct Clinical Syndrome, or Both? American Journal of Psychiatry, 165(10), 1289–1298. Pertusa, A., & Mataix-Cols, D. (2011). Structured Interview for Hoarding Disorder (SIHD). Unpublished manuscript. Raffray, T., Bond, T. L. Y., & Pelissolo, A. (2011). Correlates of insomnia in patients with social phobia: Role of depression and anxiety. Psychiatry Research, 189(2), 315–317. Rosekind, M. R., & Gregory, K. B. (2010). Insomnia risks and costs: Health, safety, and quality of life. American Journal of Managed Care, 16(8), 617–626. Samuels, J., Bienvenu, O., Riddle, M., Cullen, B., Grados, M., Liang, K., . . . Nestadt, G. (2002). Hoarding in obsessive compulsive disorder: results from a case-control study. Behaviour Research and Therapy, 40(5), 517–528. Sheehan, D., Lecrubier, Y., Sheehan, K., Amorim, P., Janavs, J., Weiller, E., . . . Dunbar, G. (1998). The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry, 59(Suppl 20), 22–33; quiz 34–57. Stein, M. B., Kroft, C. D., & Walker, J.R. (1993). Sleep impairment in patients with social phobia. Psychiatry Research, 49(3), 251–256. Steketee, G., & Frost, R. (2003). Compulsive hoarding: current status of the research. Clinical Psychology Review, 23(7), 905–927. Taylor, D. J., Mallory, L. J., Lichstein, K. L., Durrence, H., Riedel, B. W., & Bush, A. J. (2007). Comorbidity of chronic insomnia with medical problems. Sleep, 30(2), 213. Timpano, K. R., & Schmidt, N. B. (2012). The relationship between self-control deficits and hoarding: A multimethod investigation across three samples. Journal of Abnormal Psychology, 122(1), 13–25. Tolin, D. F., Kiehl, K., Worhunsky, P., Book, G., & Maltby, N. (2009). An exploratory study of the neural mechanisms of decision making in compulsive hoarding. Psychological Medicine, 39(2), 325–336.
Objective: Insomnia has been shown to have profound negative consequences on multiple aspects of daily functioning. Despite increased interest in the association between insomnia and psychopathology, no research has examined the relationships between insomnia and hoarding. The aim of the current investigation was to examine the associations between insomnia and hoarding severity. Methods: Participants consisted of patients with hoarding disorder (n = 24). Results: Results revealed that insomnia was a significant predictor of increased hoarding severity. In addition, when examining the relationships among insomnia and specific hoarding symptoms, sleep difficulties were associated with increased acquiring and difficulty discarding behaviors. Conclusions: These findings add to a growing body of literature on insomnia and various forms of psychopathology, as well as research on symptoms related to hoarding. Reducing insomnia symptoms among hoarders may help C 2015 Wiley Periodicals, Inc. to reduce hoarding-related behaviors and increase treatment efficacy. J. Clin. Psychol. 71:707–714, 2015. Keywords: hoarding; insomnia; sleep difficulties; acquiring; discarding
Sleep difficulties are a common source of distress among the general population. Research indicates that sleep difficulties are more prevalent than heart disease, cancer, diabetes, and AIDS (Lichstein, Durrence, Riedel, Taylor, & Bush, 2004), with about a third of the population experiencing sleep issues such as trouble falling asleep or waking too early (Breslau, Roth, Rosenthal, & Andreski, 1996), and 9% to 12% of the population reporting a clinically significant insomnia condition (Ford & Kamerow, 1989; Gallup Organization, 1991). Insomnia-related problems (both direct and indirect) cost an estimated $107 billion dollars annually, with the majority of cost attributed to insomnia-related absence from work, reduced productivity at work, and motor vehicle accidents (Rosekind & Gregory, 2010). In addition, insomnia is highly comorbid with several common and costly medical conditions including heart disease, high blood pressure, and diabetes, leading to increased healthcare service utilization (Rosekind & Gregory, 2010; Taylor et al., 2007). The negative effects of insomnia are further evidenced by the associations between sleep difficulties and various psychiatric conditions. Specifically, rates of comorbidity between insomnia and psychiatric disorders often range from 40% to 50% among both community and clinical samples (Harvey, 2001; Ohayon & Roth, 2003), with elevated insomnia symptoms frequently associated with increased alcohol abuse, drug abuse, and depression and mood disorders (Ohayon & Roth, 2003). Additionally, studies indicate that self-reported sleep problems may be a prodromal symptom of a first depressive episode (Perlis, Giles, Buysse, Tu, & Kupfer, 1997) and that nondepressed individuals with insomnia are twice as likely to develop depression as compared to individuals with no sleep problems (Baglioni et al., 2011). Insomnia has also been linked to numerous anxiety-related conditions. For example, research suggests that of all the anxiety disorders, generalized anxiety disorder (GAD) has the greatest comorbidity rate with insomnia (Monti & Monti, 2000), with the majority of individuals with GAD reporting that disturbances in sleep interfere with their overall functioning and daily
Please address correspondence to: Norman B. Schmidt, Department of Psychology, Florida State University, 1107 W. Call St., Tallahassee, FL 32306-4301. E-mail: [email protected] JOURNAL OF CLINICAL PSYCHOLOGY, Vol. 71(7), 707–714 (2015) Published online in Wiley Online Library (wileyonlinelibrary.com/journal/jclp).
C 2015 Wiley Periodicals, Inc. DOI: 10.1002/jclp.22161
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activities (B´elanger, Morin, Langlois, & Ladouceur, 2004). Sleep disturbances are also prevalent among individuals with obsessive-compulsive disorder (OCD). Paterson, Reynolds, Ferguson, and Dawson (2013) conducted a systematic literature review on insomnia in OCD and found that individuals with OCD often exhibited delayed onset of sleep, with more severe OCD associated with increased sleep disturbances. In addition to GAD and OCD, insomnia-related problems are also prevalent among individuals with specific phobia, panic disorder, and posttraumatic stress disorder (PTSD; Lamarche & De Koninck, 2007; Ohayon, 1997). Although a positive association between insomnia and numerous anxiety-related conditions has been firmly established, the relationship between insomnia and hoarding has yet to be examined. Hoarding disorder is a complex clinical phenomenon characterized by an accumulation of and failure to discard a large number of possessions resulting in debilitating clutter (Frost & Hartl, 1996). Once thought to be a rather rare condition, hoarding is now estimated to affect between 2% and 6% of the population (American Psychiatric Association [APA], 2013). In its most severe states, hoarding can cause significant health problems due to unsanitary conditions, social withdrawal, work disability, and even death (Frost, Steketee, & Williams, 2000; Kim, Steketee, & Frost, 2001). Hoarding has been observed in a number of psychiatric conditions including social phobia, depression, and personality disorders (Frost, Steketee, & Tolin, 2011; Frost, Steketee, Williams, & Warren, 2000) but was initially thought to be a variant of OCD. Whereas there is little doubt that hoarding can occur in the context of obsessive- and compulsive-related symptoms (Pertusa et al., 2008), there is an increasing body of data indicating distinct developmental trajectories (Samuels et al., 2002), diagnostic features (Pertusa et al., 2010), and patterns of comorbidity (Pertusa et al., 2008). In light of this accumulating evidence, hoarding disorder has been included as a discrete diagnostic entity within the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5; APA, 2013). Despite the lack of information regarding sleep difficulties among hoarding populations, it is reasonable to assume that hoarders may be at increased risk for insomnia. One aspect of hoarding in particular that may be contributing to sleep difficulties is clutter. Over the last decade, clutter has been identified as a cardinal feature of hoarding disorder and a core source of functional impairment. For instance, in their initial definition of hoarding, Frost and Hartl (1996) posit that clinically significant hoarding cannot occur in the absence of clutter. Further, they state that the majority of impairment associated with hoarding is a direct result of the influence that clutter has on an individual’s life. This impairment includes but is not limited to an inability to perform activities of daily living such as preparing food, maintaining hygiene, and sleeping (Frost & Hartl, 1996). For example, among a statewide survey of various health departments, Frost, Steketee, and Williams (2000) found that in approximately 90% of cases, clutter prevented individuals from accessing basic furniture. Given that clutter often precludes one from using their living spaces for their intended purpose, hoarders are often forced to complete activities of daily living (eating, sleeping, etc.) in one small space. Considering that all these activities are taking place in the same area in which they are likely sleeping, hoarders could be at risk for poor sleep hygiene, which would contribute to symptoms of insomnia (Bootzin & Epstein, 2011). This conceptualization is consistent with the stimulus dyscontrol model of insomnia in which cues not associated with sleep (e.g., items associated with daytime activities such as television, food, work) in the sleeping area may interfere with sleep promoting processes (Bootzin, 1973). When coupled with the high prevalence rates of insomnia symptoms among other anxiety-related conditions (Monti & Monti, 2000; Ohayon, 1997; Paterson et al., 2013), this points to a potential relationship between hoarding and symptoms of insomnia. To our knowledge, no research to date has explored the associations between insomnia and hoarding severity. The current study sought to examine the associations between insomnia and hoarding in a sample of individuals with hoarding disorder. Based on the extant literature establishing an association between insomnia and various forms of psychopathology, we hypothesized that symptoms of insomnia would be associated with increased hoarding severity, even after controlling for mood and PTSD diagnoses, which have both been found to be highly comorbid with hoarding and insomnia (Frost et al., 2011; Harvey, Jones, & Schmidt, 2003). In
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addition, we examined the associations among insomnia and specific hoarding symptoms (i.e., acquiring, difficulty discarding, and clutter). Given the considerable impairment associated with clutter and the likelihood of poor sleep hygiene among this population, it was hypothesized that symptoms of insomnia would be most associated with the clutter component of hoarding.
Methods Participants A total of 24 individuals with hoarding disorder participated in the current study. To be eligible for inclusion, participants had to be 18 years of age or older, be English speakers, and have a diagnosis of hoarding as determined by the Structured Interview for Hoarding Disorder (SIHD; Pertusa & Mataix-Cols, 2011). In addition to a diagnosis of hoarding, 54.2% of the sample met for a current anxiety diagnosis, 50% met for a current mood diagnosis, 25% met for current PTSD, 4.2% met for current OCD, 4.2% met for a current substance use disorder, and 4.2% met for an eating disorder. The sample was primarily female (87.5%), ranging from 18 to 63 years of age (mean [M] = 41.67, standard deviation [SD] = 15.18). Participant’s race was distributed as such: 62.5% Caucasian and 37.5% African American. Approximately 58% of the sample was single, 8.3% married, 20.8% divorced or separated, 8.3% cohabitating, and 4.2% widowed.
Procedure Participants in the current study were recruited from the community and an outpatient anxiety disorders clinic to participate in a research study examining environmental influences on hoarding behaviors. Upon arrival to the laboratory, informed consent was obtained. Next participants completed the Mini International Neuropsychiatric Interview (MINI; Sheehan et al., 1998), a battery of self-report questionnaires, and several study-specific tasks. After completing all tasks, participants were debriefed, thanked for their time, and compensated $20 cash for their participation. All procedures were approved by the university’s institutional review board.
Measures–Clinician Administered PTSD and Major Depressive Disorder (MDD). Diagnoses of PTSD and mood disorders were assessed using the MINI (Sheehan et al., 1998). The MINI is a brief structured clinical interview for DSM-IV and International Classification of Diseases Tenth Revision (ICD-10) psychiatric disorders. A highly trained, doctoral-level clinical psychology graduate student, who was advised by a licensed clinical psychologist to ensure accurate diagnosis, administered the MINI. The MINI is compatible with international diagnostic criteria, including the DSM-IV (Sheehan et al., 1998). Hoarding. Hoarding was assessed using the SIHD (Pertusa & Mataix-Cols, 2011). The SIHD is a structured interview that was developed based on the provisional criteria for hoarding disorder diagnosis before completion of the DSM-5. The interview contains detailed questions regarding each of the six criteria for hoarding disorder. Measures–Self-Report Hoarding. Hoarding behaviors were assessed using the Saving Inventory-Revised (SIR; Frost, Steketee, & Grisham, 2004). The SIR is a 23-item self-report questionnaire that assesses hoarding behaviors, including acquiring, clutter, and difficulty discarding (Frost et al., 2004). Participants rate each item using a 5-point Likert scale ranging from 0 to 4, with higher scores indicating increased frequency and severity of hoarding behaviors. The SIR has demonstrated strong internal consistency as well as good test-retest reliability (Coles, Frost, Heimberg, & Steketee, 2003; Frost et al., 2004). The SIR demonstrated good internal consistency in the
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Table 1 Zero-Order Correlations, Means, and Standard Deviations
1. ISI 2. SIR 3. SIR-C 4. SIR-A 5. SIR-D
1
2
– .46* .24 .48* .36
– .74*** .91*** .76***
3
– .50* .27
4
– .64**
5
Mean
SD
–
14.88 58.42 23.26 15.78 19.39
5.09 12.12 5.05 6.09 4.13
Note. SD = standard deviation; ISI = Insomnia Severity Index–Total Score; SIR = Saving Inventory Revised –Total Score; SIR-C = Saving Inventory Revised-Clutter Subscale; SIR-A = Saving Inventory Revised–Acquiring Subscale; SIR-D = Saving Inventory Revised–Discarding Subscale. ***p < .001. **p < .01. *p < .05.
present investigation (α = .90). Additionally, the discarding, clutter, and acquisitioning subscales demonstrated adequate internal consistency (alphas ranged from .80 to 86).
Insomnia. Symptoms of insomnia were assessed using the Insomnia Severity Index (ISI; Bastien, Valli`eres, & Morin, 2001). The ISI is a brief seven-item self-report questionnaire assessing sleep difficulties (e.g., falling asleep, staying asleep, waking too early), satisfaction/dissatisfaction with sleep patterns, and/or interference with daily functioning. Respondents were asked to rate each item using a 5-point Likert scale ranging from 0 to 4, with higher scores reflecting more severe sleep problems. The ISI has shown evidence of high internal consistency (Bastien et al., 2001). The ISI demonstrated adequate internal consistency in the present investigation (α = .74). Results Preliminary Analyses The means, standard deviations, and zero-order correlations for all self-report measures used in the current analyses can be found in Table 1. The mean SIR score was comparable to that found in other reports using hoarding disorder populations (Timpano & Schmidt, 2012). Additionally, the mean ISI score was slightly higher than that reported in other clinical populations, suggesting that our sample was elevated on insomnia symptoms (Raffray, Bond, & Pelissolo, 2011). In line with initial predictions, symptoms of insomnia were significantly correlated with hoarding severity (r = .46). Inconsistent with prediction, however, insomnia severity was not correlated with the clutter domain of hoarding (r = .24), but rather it was associated only with the acquiring subfactor (r = .48). Regarding insomnia severity, 12.5% of the sample scored in the nonclinical range, 37.5% scored in the subthreshold range, and 50% scored in the clinically significant range.
Primary Analyses A hierarchical regression equation was computed to examine the association between sleep disturbances (using the ISI) and hoarding severity (using the SIR). Preliminary analyses indicated that there were no threats or violations of normality, multicollinearity, or homoscedasticity. In the first step of the model, the presence of a mood diagnosis (as measured by the MINI), as well as the presence of PTSD (as measured by the MINI), was entered accounting for 14.4% of the variance in hoarding severity, F(2, 21) = 1.77, p = .20. In the second step of the model, ISI total scores were added accounting for an additional 27% of the variance (F-change = 9.21, p = .007) in hoarding severity. Results revealed that insomnia severity was significantly associated with
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hoarding severity (β = .53, t = 3.04, p = .007, sr2 = .27) above and beyond mood and PTSD diagnoses.1 Next a series of hierarchical regression analyses were performed to examine the relationships among sleep disturbances and specific hoarding symptoms (i.e., acquiring, difficulty discarding, and clutter) after controlling for the presence of a mood diagnosis and PTSD. Once again, preliminary analyses indicated no threats or violations of normality, multicollinearity, or homoscedasticity. For each regression equation, the presence of a mood or PTSD diagnosis was entered into the first step of the model. In the second step, ISI total scores were added. Results revealed that the acquiring (β = .54, t = 3.06, p = .007, sr2 = .28) and difficulty discarding (β = .46, t = 2.69, p = .014, sr2 = .20) subscales of the SIR were significantly associated with increased insomnia symptoms, whereas the clutter subscale was not (β = .28, t = 1.23, p = .23, sr2 = .07).
Discussion Results indicated that insomnia was associated with increased hoarding severity even after controlling for relevant covariates. These results are consistent with initial prediction and support previous research demonstrating associations between symptoms of insomnia and psychopathology (B´elanger et al., 2004; Craske & Rowe, 1997; Stein, Kroft, & Walker, 1993). When examining the associations between specific hoarding facets (i.e., acquiring, difficulty discarding, and clutter) and sleep disturbances, results revealed that symptoms of insomnia were associated with the excessive acquiring and difficulty discarding domains of hoarding. While unanticipated, these findings are consistent with research demonstrating that sleep disturbances are associated with increased reward motivated behaviors and blunted activity in decisionmaking regions of the brain. For example, research has demonstrated that sleep deprivation can enhance activity within the striatum and amygdala, two reward sensitive regions of the brain (Benedict et al., 2012). This overactivity appears to trigger a state in which rewards are overvalued and losses are undervalued (Goldstein & Walker, 2014). It has been suggested that acquiring behaviors, much like impulse control disorders, are driven by positive emotional states and reward motivated behaviors (Steketee & Frost, 2003). Moreover, when making decisions regarding whether to keep or discard a possession, hoarders have been found to display excessive hemodynamic activity in the orbital frontal cortex, a region of the brain that is associated with processing relative reward value (Tolin, Kiehl, Worhunsky, Book, & Maltby, 2009). Given that sleep difficulties affect one’s decision-making abilities, it is reasonable to assume that symptoms of insomnia may be one factor contributing to the excessive acquiring and difficulty discarding symptoms of hoarding. Inconsistent with initial predictions, we did not find a significant association between symptoms of insomnia and the clutter domain of hoarding. Although unanticipated, it is possible that clutter is more associated with other aspects of sleep apart from insomnia. Indeed, insomnia, which involves a difficulty initiating sleep, maintaining sleep, or waking up too early (Edinger et al., 2004), is just one type of sleep problem. Previous research has indicated that other aspects of sleep difficulties including sleep quality, sleep duration, circadian rhythm disturbances, nightmares, or daytime dysfunction may also be associated with mental health problems (Asarnow, Soehner, & Harvey, 2013; Germain, 2013). Thus, it is possible that clutter is associated with impaired sleep quality or shorter sleep duration constructs, which are not assessed in our measure of insomnia (i.e., ISI). Future research should continue to investigate the relations between insomnia, sleep quality, and other types of sleep disturbances among hoarding populations. Taken together, these findings have important implications for the larger framework of Frost and Hartl’s (1996) cognitive behavioral model of hoarding. According to this model, hoarding 1 To ensure that the relationship between insomnia and hoarding was not due to co-occuring anxiety disorder
diagnoses, separate regression equations were computed controlling for mood, PTSD, and anxiety disorder diagnoses. Results remained significant.
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is a multifaceted problem stemming from various information processing deficits in the areas of attention, decision making, and memory. For example, hoarders frequently shift their attention from one object to another, causing an inability to make decisions or follow through with decisions during tasks such as discarding (Frost & Gross, 1993). Additionally, hoarders doubt their ability to remember information. Saving items is a way of retaining this information without having to actually remember it (Frost & Steketee, 1998). Given that individuals with insomnia often complain of attention, concentration, and memory impairment (for review, see Bootzin and Epstein, 2011), sleep-related problems may be one factor contributing to the information processing deficits seen among hoarders; that is, sleep-related problems may create a vicious cycle in which the cognitive deficits observed among hoarders are continuously perpetuated by a lack of sleep. Results of the present study suggest insomnia may be an important but often overlooked factor that affects the symptoms of hoarding disorder. In terms of clinical implications, clinicians should inquire about symptoms of insomnia among hoarding disorder patients and the degree to which these symptoms affect specific hoarding behaviors to determine if interventions are needed. Indeed, treating insomnia through interventions such as cognitive behavioral therapy for insomnia (CBT-I) has been shown to improve co-occurring symptoms of anxiety disorders in a number of studies (Belleville, Cousineau, Levrier, & St-Pierre-Delorme, 2011). Additionally, treatment of insomnia leads to enhanced treatment outcomes for mood disorders such as depression (Manber et al., 2008). Considering this previous research as well as the current findings, it raises the question of whether targeting insomnia among individuals with hoarding disorder could lead to overall symptom improvement and enhanced treatment outcomes.
Limitations The current study should be considered in the context of its limitations. First, due to the cross-sectional design of the study, causal inferences cannot be made. Although it is likely that impairments in emotion regulation and cognitive functioning due to sleep loss affect the symptoms of hoarding disorder, particularly acquiring and difficulty discarding, it is also possible that symptoms of hoarding (i.e., clutter obstructing one’s sleeping area) may increase symptoms of insomnia, or that a bidirectional relationship exists between the two (Harvey, 2011). Future research should employ experimental and prospective designs to determine the causal nature of this association. In addition, although we used a well-validated measure of insomnia (Bastien et al., 2001) that has demonstrated associations with objective measures of sleep (i.e., polysomnographic evaluation), we did rely on self-reported symptoms of insomnia. Future studies could index insomnia through objective methods such as actigraphy and polysomnography to strengthen these findings. Finally, our sample size was relatively small, and future research should attempt to replicate these findings in larger samples of individuals with hoarding disorder.
Conclusion Despite these limitations, the current investigation provides important information regarding the relationship between insomnia and hoarding. To our knowledge, this investigation is the first to examine the relationship between these two constructs. It appears that insomnia is a robust, significant predictor of increased hoarding severity, specifically acquiring and difficulty discarding. This association was particularly strong, with symptoms of insomnia uniquely accounting for 28% of the total variance in hoarding severity. Considering the lack of information on risk factors for hoarding, these findings add considerably to the growing body literature on hoarding disorder and insomnia within various anxiety-related conditions.
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