HHS Public Access Author manuscript Author Manuscript
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01. Published in final edited form as: Psychol Addict Behav. 2016 November ; 30(7): 755–763. doi:10.1037/adb0000193.
Posttraumatic Stress Disorder Symptoms, Anxiety Sensitivity, and Alcohol Use Motives in College Students with a History of Interpersonal Trauma Erin C. Berenz, Ph.D.a,b, Salpi Kevorkian, B.A.a, Nadia Chowdhury, B.S.b, Danielle M. Dick, Ph.D.c,d, Kenneth S. Kendler, M.D.b, and Ananda B. Amstadter, Ph.D.b,c
Author Manuscript
aDepartment
of Pediatrics, University of Virginia, Charlottesville, VA, USA
bDepartment
of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA
cDepartment
of Psychology, Virginia Commonwealth University, Richmond, VA, USA
dDepartment
of African American Studies, Virginia Commonwealth University, Richmond, VA,
USA
Abstract
Author Manuscript Author Manuscript
Posttraumatic stress disorder (PTSD) symptoms are associated with coping motivated alcohol use in trauma-exposed samples. However, it is unclear which individuals experiencing PTSD symptoms are at greatest risk for alcohol use problems following trauma exposure. Individuals endorsing high in anxiety sensitivity, the fear of anxiety and related sensations, may be particularly motivated to use alcohol to cope with PTSD symptoms. The current study examined the moderating role of anxiety sensitivity in the association between PTSD symptoms and coping motives in a sample of 295 young adults with a history of interpersonal trauma and current alcohol use. Participants completed measures of past 30-day alcohol consumption, trauma history, current PTSD symptoms, anxiety sensitivity, and alcohol use motives. Results of hierarchical multiple regression analyses indicated that greater anxiety sensitivity was significantly associated with greater coping (β=.219) and conformity (β=.156) alcohol use motives, and greater PTSD symptoms were associated with greater coping motives (β=.247), above and beyond the covariates of sex, alcohol consumption, trauma load, and non-criterion alcohol use motives. The interaction of anxiety sensitivity and PTSD symptoms accounted for additional variance in coping motives above and beyond the main effects (β=.117), with greater PTSD symptoms being associated with greater coping motives among those high but not low in anxiety sensitivity. Assessment and treatment of PTSD symptoms and anxiety sensitivity in young adults with interpersonal trauma may be warranted as a means of decreasing alcohol-related risk in trauma-exposed young adults.
Keywords posttraumatic stress disorder; anxiety sensitivity; alcohol; coping; motives
Corresponding author: Erin C. Berenz, Ph.D.; Department of Pediatrics; University of Virginia; Stacey Hall; 1105 West Main St. – Box 800828; Charlottesville, VA 22908; Phone: (434)982-4321; Fax: (434)924-2780; [email protected].
Berenz et al.
Page 2
Author Manuscript
Introduction
Author Manuscript
Posttraumatic stress disorder (PTSD) and alcohol use disorders (AUDs) frequently co-occur (Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995), with approximately 50% of individuals seeking treatment for AUDs meeting current criteria for PTSD (Brown, Stout, & Mueller, 1999). Individuals exposed to interpersonal trauma (e.g., physical/sexual assault) compared to accidental trauma (e.g., natural disasters, motor vehicle accidents) appear to be at greatest risk for PTSD and comorbid psychopathology (Kessler et al., 1995). Exposure to interpersonal trauma is associated with greater likelihood of alcohol use problems, and vice versa. For example, women exposed to violence who develop alcohol abuse are more vulnerable to revictimization compared to those not abusing alcohol (Messman-Moore & Long, 2003). Individuals with PTSD compared to individuals without PTSD also have poorer AUD treatment prognosis. For example, PTSD is associated with faster relapse following treatment (Brown et al., 1999), potentially due in part to their experience of cravings being more intense than those of patients without PTSD (Coffey et al., 2002; Drapkin et al., 2011).
Author Manuscript Author Manuscript
Shared familial liability (i.e., shared environment and genetic factors) accounts for a portion of PTSD-AUD comorbidity (Stein et al., 2002; True et al., 1993; Xian et al., 2000); however, the self-medication model of comorbidity is the predominant explanatory model in the PTSD-AUD literature. This model posits that individuals with PTSD are at heightened risk for AUDs due to a tendency to use alcohol as a means of coping with unwanted negative affect (Khantzian, 1999). A significant body of literature supports this model. Individuals with, compared to without, PTSD are more likely to use alcohol as a coping strategy (Waldrop, Back, Verduin, & Brady, 2007), and coping-oriented alcohol use partially mediates an association between PTSD symptoms and problem drinking (O’Hare & Sherrer, 2011). Individuals with co-occurring PTSD and alcohol dependence also demonstrate increased subjective and physiological craving in response to personalized trauma cues, even outside of the context of an alcohol cue (Coffey et al., 2002; Coffey et al., 2010), which may indicate a learned association between trauma memories and alcohol use. Coping motives for alcohol use also influence the association between PTSD symptoms and drinking outcomes. For example, coping motives for alcohol use, but no other motives, have been shown to mediate an association between childhood trauma exposure and alcohol problems (Grayson, & Nolen-Hoeksema, 2005), as well as an association between PTSD symptoms and alcohol consumption among individuals with a history of interpersonal trauma (Kaysen et al., 2007). Results of a daily monitoring study also have supported prospective associations between increased PTSD symptom severity and same- and next-day increases in alcohol use, particularly among those endorsing high levels of coping motives and low levels of enhancement motives (Simpson, Stappenbeck, Luterek, Lehavot, & Kaysen, 2014). In spite of evidence linking PTSD symptoms with coping-oriented alcohol use, potential mechanisms accounting for this association are not clear. Anxiety sensitivity, the fear of anxiety and related sensations (McNally, 1996), may help explain associations between PTSD and alcohol phenotypes. Anxiety sensitivity has demonstrated relevance to PTSD etiology and maintenance more broadly, such that high anxiety sensitivity is associated with increases in PTSD symptoms over time, and PTSD symptom severity predicts increases in
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 3
Author Manuscript
anxiety sensitivity (Marshall, Miles, & Stewart, 2010). Individuals high in anxiety sensitivity also exhibit poorer PTSD treatment response (Zandberg et al., 2016). Given that the selfmedication hypothesis presumes that alcohol is being used as a means to dampen unwanted physiological and emotional arousal, it would follow that individuals who are more reactive to symptoms of anxious arousal (i.e., those high in anxiety sensitivity) would be particularly likely to seek out negative reinforcement strategies (e.g., alcohol use) in the face of such arousal. Specifically, high anxiety sensitivity individuals who are experiencing greater levels of PTSD symptoms may be at especially high risk for engaging in coping-oriented alcohol use. Anxiety sensitivity has demonstrated significant associations with constructs related to avoidance of negative affect, including coping motives for alcohol (Chandley, Luebbe, Messman-Moore, & Ward, 2014) and other substance use (e.g., Johnson, Mullin, Marshall, Bonn-Miller, & Zvolensky, 2010), as well as experiential avoidance more generally (Kashdan, Barrios, Forsyth, & Steger, 2006). Further, theoretical models based on review of the available research suggest that coping motives for alcohol use likely mediate an association between anxiety sensitivity and drinking behavior (DeMartini & Carey, 2011). Anxiety sensitivity also has evidenced associations with conformity motives for alcohol use (i.e., drinking to “fit in” with peers) in a general undergraduate sample endorsing alcohol use (Stewart, Zvolensky, & Eifert, 2002). However, no studies to our knowledge have examined the role of anxiety sensitivity in the association between PTSD symptoms and motives for alcohol use. One past study of individuals with comorbid PTSD-AUD has found support for a stronger association between PTSD symptoms and alcohol consumption among those low compared to high in anxiety sensitivity (Gillihan, Farris, & Foa, 2011); however, other work has indicated stronger associations between anxiety sensitivity and drinking behavior among those with higher psychiatric symptoms (DeMartini & Carey, 2011).
Author Manuscript Author Manuscript
The primary aim of the current study was to examine associations among PTSD symptoms, anxiety sensitivity, and motives for alcohol use in a sample of college students endorsing lifetime interpersonal trauma exposure and current alcohol use. Consistent with past findings in trauma-exposed young adults (Vujanovic, Marshall-Berenz, & Zvolensky, 2011), it was hypothesized that greater levels of PTSD symptoms would be associated with greater coping motives for alcohol use, but no other alcohol use motives, above and beyond the covariates of sex, trauma load, alcohol consumption, and non-coping alcohol use motives. It also was hypothesized that higher anxiety sensitivity would be associated with greater coping and conformity alcohol use motives, as has been found in past research in non-trauma exposed individuals (e.g., Stewart, Zvolensky, & Eifert, 2002). Finally, it was hypothesized that anxiety sensitivity would moderate an association between PTSD symptoms and coping motives for alcohol use, but no other drinking motives, such that greater PTSD symptoms would be associated with greater coping motives among those high, but not low, in anxiety sensitivity.
Author Manuscript
Method Participants Participants were 295 undergraduate students (74.0% women) participating in “Spit for Science,” a genetically informed university-wide study (hereafter referred to as the “parent
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 4
Author Manuscript
study”) investigating the progression and correlates of substance use and emotional health in college students at Virginia Commonwealth University (Dick et al., 2014). Individuals from the first three cohorts of the parent study were invited to determine eligibility for the current study if they endorsed possible interpersonal trauma history (via brief screener) and current alcohol use at any timepoint in the parent study. A comprehensive assessment of potentially traumatic event (PTE) exposure was conducted in the current study (described below). Participants from the parent study had completed 1–3 waves of assessment at the time of study recruitment, depending on their cohort and their ongoing participation in the follow-up sessions. Interested individuals completed an online screening item to determine whether they had used alcohol in the past 30 days. Individuals were excluded if they did not endorse past-30 day alcohol use. Measures
Author Manuscript Author Manuscript
The Traumatic Life Events Questionnaire (TLEQ; Kubany, 2000) is a 23-item self-report measure assessing whether and when participants experienced a range of PTEs (e.g., natural disaster, assault, accidents, illness/injury) and how many times each PTE occurred. For each event endorsed, participants are asked the number of times the event occurred. Participants are also asked to identify their most distressing event, when it first and last occurred, and rate the amount of distress the event causes on a scale ranging from “no distress” to “extreme distress.” The TLEQ has evidenced good test-retest reliability and good convergent validity with interview assessments of PTE (Kubany, 2000). The TLEQ was used in the current study to confirm the presence of a history of interpersonal PTE, defined as lifetime history of directly experiencing or witnessing physical assault, sexual assault, or unwanted sexual experiences (see Table 1 for a list of interpersonal PTEs included in the current study). The TLEQ also was used as a measure of trauma load, defined as the total number of PTE categories that an individual endorsed. The PTSD Checklist for DSM-5 (PCL-5; Weathers et al., 2013) is a 20-item self-report measure used to assess PTSD symptoms for individuals’ “most traumatic” PTE. Each item corresponds to the symptom criteria for PTSD in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association, 2013). Participants indicated the degree to which they have been bothered by a specific problem (e.g., “repeated, disturbing dreams of a stressful experience from the past”) in the past 30 days on a scale ranging from 0 (“not at all”) to 4 (“extremely”). The PCL-5 evidences good reliability and validity in young adult college samples (Blevins et al., 2015). The current study utilized the PCL-5 total score as a measure of PTSD symptoms (alpha=.94), and used a cut-off score of 38 to indicate a positive PTSD screen (Weathers et al., 2013).
Author Manuscript
The Anxiety Sensitivity Index-3 (ASI-3; Taylor et al. 2007) is an 18-item self-report measure that assesses the degree to which individuals fear anxiety and related sensations. It consists of three highly related subscales corresponding to the three sub-factors of anxiety sensitivity: physical concerns (e.g., “It scares me when my heart beats rapidly”), cognitive concerns (e.g., “It scares me when I’m unable to keep my mind on task”), and social concerns (e.g., “I worry that other people will notice my anxiety”). Respondents indicate the degree to which they believe each statement applies to them on a Likert scale from 0 (“very
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 5
Author Manuscript
little”) to 4 (“very much”). The current study utilized the ASI-3 total score as a measure of global anxiety sensitivity (alpha=.92). Current alcohol consumption was assessed via items querying past 30-day alcohol use quantity (i.e., “On the days that you drank during the past 30 days, how many drinks did you usually have each day?”) and frequency (i.e., “During the past 30 days, how many days did you drink one or more drinks of an alcoholic beverage?”). The measure was adapted from the Timeline Follow-back (TLFB; Sobell & Sobell, 1992). Past 30-day alcohol use quantity and frequency were included as covariates in the current study.
Author Manuscript
The Alcohol Use Disorders Identification Test (AUDIT; Babor, de la Fuente, Sauders, & Grant, 1992) is a 10-item self-report screening measure developed by the World Health Organization to identify individuals with alcohol problems. There is a large body of literature attesting to the psychometric properties of the AUDIT (e.g., Saunders, Aasland, Babor, de la Fuente, &Grant, 1993). The current study utilized the AUDIT as a descriptive measure of alcohol-related problems (alpha=.80). Individuals scoring an 8 or higher on the AUDIT likely meet criteria for at least “moderate” alcohol problems (Babor et al., 1992).
Author Manuscript
The Drinking Motives Questionnaire (DMQ), with inclusion of the DMQ-Revised Conformity items (Cooper, 1994) was administered to assess drinking motives. The DMQ indexes the frequency of drinking (i.e., almost never/never, sometimes, often, almost always) for four distinct motives: DMQ-Coping (e.g., “to forget your worries”), DMQ-Enhancement (e.g., “because you like the feeling”), DMQ-Conformity (e.g., “because your friends pressure you to drink”), and DMQ-Social (e.g., to be sociable”). The DMQ-R demonstrates good structural and criterion validity, as well as high internal consistency (Cooper, 1994; MacLean & Lecci, 2000). Due to significant kurtosis, the DMQ-Conformity subscale underwent a log transformation to improve normality (pre-transformation: skewness = 2.49, kurtosis = 7.35; post-transformation: skewness = 1.60, kurtosis = 2.19). No other subscales required transformation. Alphas in the current study ranged from .81-.85. Procedures
Author Manuscript
Overview of parent study—During students’ first week of freshman year, they received an email inviting them to participate in the “Spit for Science” study, which contained a link to an online survey with questions about personality and behavior, family, friends, and experiences growing up. Participants who initiated the survey consented online and completed a battery of assessments. After completion of the online survey, participants provided a salivary DNA sample and received compensation from a member of the research team. Participants were followed with annual surveys each spring throughout the duration of their college years. Full details on the study methods can be found in the “Spit for Science” study publication (Dick et al., 2014). Study data for the parent study and current study were collected and managed using REDCap (Research Electronic Data Capture), hosted at Virginia Commonwealth University (Harris et al., 2009). REDCap is a secure, web-based application for collecting and storing data.
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 6
Author Manuscript
Recruitment from the parent study—PTEs were assessed in the parent study via an abbreviated version of the Life Events Checklist (Gray, Litz, Hsu, & Lombardo, 2004), which assessed five different stressful life event categories: natural disasters, physical assaults, sexual assaults, other unwanted or uncomfortable sexual experiences, and transportation accidents. Past 30-day alcohol use frequency was assessed in the parent study on a 5-point scale ranging from 1 (“Never”) to 5 (“Four or more times a week”). Participants endorsing any PTE (with the exception of natural disaster, which was over-endorsed in the parent study) at any assessment point, as well as current alcohol use at any assessment point, were recruited for the current study. The current study recruited participants from the first three cohorts of the parent study (N=7,603; 61.1% women; 50.2% Caucasian, 19.5% Black, 16.3% Asian, 14% other), who enrolled between 2011–2013.
Author Manuscript Author Manuscript
Current Study Procedure—Potentially eligible participants received an email via REDCap from the parent study registry staff, introducing the current study (e.g., providing a brief study description and a link to a study website) and requesting permission to be contacted by the research team. Of the 3,570 initially contacted, 21.1% (n=755) made contact with the research team by completing a form indicating their interest in learning more about the study. Interested participants were sent a link to the online consent form, brief screening item (i.e., “Have you had one or more alcoholic drinks (e.g., beer, wine, liquor) in the past 30 days?”), and survey enrollment link. Seventy four percent of interested individuals (n=557) endorsed current alcohol use and consented to participate. After completing online informed consent procedures, they completed a battery of self-report and behavioral measures online via REDCap. Of the individuals who consented, 86.8% (n=501) of the sample completed all measures. Based on responses to the TLEQ, 295 participants (8.3% of those initially contacted) endorsed one or more instances of interpersonal PTE and were included in the current study analyses. Participants were paid $20 in cash for completing the study. The Institutional Review Board at Virginia Commonwealth University approved all study procedures for both the parent study and the current study. Data Analytic Plan
Author Manuscript
Analyses were conducted in SPSS Statistics 22. Zero-order correlations were examined among demographic and primary study variables. To address the primary study hypotheses, four hierarchical linear regressions were conducted. Prior to conducting the regression analyses, all continuous variables were converted to standard z-scores. The covariates of sex (1=male, 2=female), past 30-day alcohol use frequency and quantity, trauma load (i.e., number of trauma categories endorsed), and non-criterion DMQ subscales were entered at level 1 of the models. The main effects of PCL-5 total score and ASI-3 total score were entered at level 2. The interaction term (PCL-5*ASI-3) was entered at level 3. Criterion variables were: DMQ-coping, DMQ-social, DMQ-enhancement, and DMQ-conformity. The forms of any significant interactions were subsequently examined both graphically, as per recommendations from Cohen and Cohen (1983), and statistically (Holmbeck, 2002). First, on the basis of recommendations of Cohen and Cohen (pp. 323, 419), we examined the form of these interactions by inserting specific values for each predictor variable (1/2 SD above and below the mean) into the regression equation associated with the described analysis. Then, on the basis of recommendations of Holmbeck (2002), we conducted post hoc probing
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 7
Author Manuscript
analyses to examine the significance of the simple slopes at each level of the moderator. Bonferroni correction was applied for the regression models to correct for multiple testing, with an adjusted p-value of .013 indicating statistical significance.
Results Descriptive Statistics and Zero-Order Correlations
Author Manuscript
See Table 1 for descriptive statistics. The sample was racially diverse (more than a third identifying as non-white) and predominately female. A range of PTEs was endorsed, with the most frequent interpersonal PTEs being threatened death or serious injury, witnessing family violence, and sexual abuse prior to age 13. High rates of accidental trauma also were endorsed, and participants endorsed a mean of 5 types of PTEs across all categories. The mean PCL-5 score for the overall sample was in the subclinical range for PTSD symptoms, with approximately one-fifth of the sample screening positive for PTSD. Approximately half of the sample scored an 8 or higher on the AUDIT, consistent with at least moderate alcohol problems. Table 2 presents correlations among the primary study variables. Female sex was associated with greater number of lifetime PTE types and greater PTSD symptoms, and male sex was associated with greater alcohol use quantity and frequency, as well as greater motivation to use alcohol for social, enhancement, and conformity reasons. Number of lifetime PTE types was positively associated with PTSD symptoms (PCL-5), anxiety sensitivity (ASI-3), and coping motives for alcohol use (DMQ-Coping), but no other drinking motives. PTSD symptoms (PCL-5) and anxiety sensitivity (ASI-3) were positively correlated with all drinking motives, and all drinking motives were positively correlated with one another.
Author Manuscript
PTSD symptoms, Anxiety Sensitivity, and Alcohol Use Motives
Author Manuscript
See Table 3 for regression output. The model accounted for 51.3% of variance in coping motives (DMQ-Coping; F(10, 293)=31.90, p
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01. Published in final edited form as: Psychol Addict Behav. 2016 November ; 30(7): 755–763. doi:10.1037/adb0000193.
Posttraumatic Stress Disorder Symptoms, Anxiety Sensitivity, and Alcohol Use Motives in College Students with a History of Interpersonal Trauma Erin C. Berenz, Ph.D.a,b, Salpi Kevorkian, B.A.a, Nadia Chowdhury, B.S.b, Danielle M. Dick, Ph.D.c,d, Kenneth S. Kendler, M.D.b, and Ananda B. Amstadter, Ph.D.b,c
Author Manuscript
aDepartment
of Pediatrics, University of Virginia, Charlottesville, VA, USA
bDepartment
of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA
cDepartment
of Psychology, Virginia Commonwealth University, Richmond, VA, USA
dDepartment
of African American Studies, Virginia Commonwealth University, Richmond, VA,
USA
Abstract
Author Manuscript Author Manuscript
Posttraumatic stress disorder (PTSD) symptoms are associated with coping motivated alcohol use in trauma-exposed samples. However, it is unclear which individuals experiencing PTSD symptoms are at greatest risk for alcohol use problems following trauma exposure. Individuals endorsing high in anxiety sensitivity, the fear of anxiety and related sensations, may be particularly motivated to use alcohol to cope with PTSD symptoms. The current study examined the moderating role of anxiety sensitivity in the association between PTSD symptoms and coping motives in a sample of 295 young adults with a history of interpersonal trauma and current alcohol use. Participants completed measures of past 30-day alcohol consumption, trauma history, current PTSD symptoms, anxiety sensitivity, and alcohol use motives. Results of hierarchical multiple regression analyses indicated that greater anxiety sensitivity was significantly associated with greater coping (β=.219) and conformity (β=.156) alcohol use motives, and greater PTSD symptoms were associated with greater coping motives (β=.247), above and beyond the covariates of sex, alcohol consumption, trauma load, and non-criterion alcohol use motives. The interaction of anxiety sensitivity and PTSD symptoms accounted for additional variance in coping motives above and beyond the main effects (β=.117), with greater PTSD symptoms being associated with greater coping motives among those high but not low in anxiety sensitivity. Assessment and treatment of PTSD symptoms and anxiety sensitivity in young adults with interpersonal trauma may be warranted as a means of decreasing alcohol-related risk in trauma-exposed young adults.
Keywords posttraumatic stress disorder; anxiety sensitivity; alcohol; coping; motives
Corresponding author: Erin C. Berenz, Ph.D.; Department of Pediatrics; University of Virginia; Stacey Hall; 1105 West Main St. – Box 800828; Charlottesville, VA 22908; Phone: (434)982-4321; Fax: (434)924-2780; [email protected].
Berenz et al.
Page 2
Author Manuscript
Introduction
Author Manuscript
Posttraumatic stress disorder (PTSD) and alcohol use disorders (AUDs) frequently co-occur (Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995), with approximately 50% of individuals seeking treatment for AUDs meeting current criteria for PTSD (Brown, Stout, & Mueller, 1999). Individuals exposed to interpersonal trauma (e.g., physical/sexual assault) compared to accidental trauma (e.g., natural disasters, motor vehicle accidents) appear to be at greatest risk for PTSD and comorbid psychopathology (Kessler et al., 1995). Exposure to interpersonal trauma is associated with greater likelihood of alcohol use problems, and vice versa. For example, women exposed to violence who develop alcohol abuse are more vulnerable to revictimization compared to those not abusing alcohol (Messman-Moore & Long, 2003). Individuals with PTSD compared to individuals without PTSD also have poorer AUD treatment prognosis. For example, PTSD is associated with faster relapse following treatment (Brown et al., 1999), potentially due in part to their experience of cravings being more intense than those of patients without PTSD (Coffey et al., 2002; Drapkin et al., 2011).
Author Manuscript Author Manuscript
Shared familial liability (i.e., shared environment and genetic factors) accounts for a portion of PTSD-AUD comorbidity (Stein et al., 2002; True et al., 1993; Xian et al., 2000); however, the self-medication model of comorbidity is the predominant explanatory model in the PTSD-AUD literature. This model posits that individuals with PTSD are at heightened risk for AUDs due to a tendency to use alcohol as a means of coping with unwanted negative affect (Khantzian, 1999). A significant body of literature supports this model. Individuals with, compared to without, PTSD are more likely to use alcohol as a coping strategy (Waldrop, Back, Verduin, & Brady, 2007), and coping-oriented alcohol use partially mediates an association between PTSD symptoms and problem drinking (O’Hare & Sherrer, 2011). Individuals with co-occurring PTSD and alcohol dependence also demonstrate increased subjective and physiological craving in response to personalized trauma cues, even outside of the context of an alcohol cue (Coffey et al., 2002; Coffey et al., 2010), which may indicate a learned association between trauma memories and alcohol use. Coping motives for alcohol use also influence the association between PTSD symptoms and drinking outcomes. For example, coping motives for alcohol use, but no other motives, have been shown to mediate an association between childhood trauma exposure and alcohol problems (Grayson, & Nolen-Hoeksema, 2005), as well as an association between PTSD symptoms and alcohol consumption among individuals with a history of interpersonal trauma (Kaysen et al., 2007). Results of a daily monitoring study also have supported prospective associations between increased PTSD symptom severity and same- and next-day increases in alcohol use, particularly among those endorsing high levels of coping motives and low levels of enhancement motives (Simpson, Stappenbeck, Luterek, Lehavot, & Kaysen, 2014). In spite of evidence linking PTSD symptoms with coping-oriented alcohol use, potential mechanisms accounting for this association are not clear. Anxiety sensitivity, the fear of anxiety and related sensations (McNally, 1996), may help explain associations between PTSD and alcohol phenotypes. Anxiety sensitivity has demonstrated relevance to PTSD etiology and maintenance more broadly, such that high anxiety sensitivity is associated with increases in PTSD symptoms over time, and PTSD symptom severity predicts increases in
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 3
Author Manuscript
anxiety sensitivity (Marshall, Miles, & Stewart, 2010). Individuals high in anxiety sensitivity also exhibit poorer PTSD treatment response (Zandberg et al., 2016). Given that the selfmedication hypothesis presumes that alcohol is being used as a means to dampen unwanted physiological and emotional arousal, it would follow that individuals who are more reactive to symptoms of anxious arousal (i.e., those high in anxiety sensitivity) would be particularly likely to seek out negative reinforcement strategies (e.g., alcohol use) in the face of such arousal. Specifically, high anxiety sensitivity individuals who are experiencing greater levels of PTSD symptoms may be at especially high risk for engaging in coping-oriented alcohol use. Anxiety sensitivity has demonstrated significant associations with constructs related to avoidance of negative affect, including coping motives for alcohol (Chandley, Luebbe, Messman-Moore, & Ward, 2014) and other substance use (e.g., Johnson, Mullin, Marshall, Bonn-Miller, & Zvolensky, 2010), as well as experiential avoidance more generally (Kashdan, Barrios, Forsyth, & Steger, 2006). Further, theoretical models based on review of the available research suggest that coping motives for alcohol use likely mediate an association between anxiety sensitivity and drinking behavior (DeMartini & Carey, 2011). Anxiety sensitivity also has evidenced associations with conformity motives for alcohol use (i.e., drinking to “fit in” with peers) in a general undergraduate sample endorsing alcohol use (Stewart, Zvolensky, & Eifert, 2002). However, no studies to our knowledge have examined the role of anxiety sensitivity in the association between PTSD symptoms and motives for alcohol use. One past study of individuals with comorbid PTSD-AUD has found support for a stronger association between PTSD symptoms and alcohol consumption among those low compared to high in anxiety sensitivity (Gillihan, Farris, & Foa, 2011); however, other work has indicated stronger associations between anxiety sensitivity and drinking behavior among those with higher psychiatric symptoms (DeMartini & Carey, 2011).
Author Manuscript Author Manuscript
The primary aim of the current study was to examine associations among PTSD symptoms, anxiety sensitivity, and motives for alcohol use in a sample of college students endorsing lifetime interpersonal trauma exposure and current alcohol use. Consistent with past findings in trauma-exposed young adults (Vujanovic, Marshall-Berenz, & Zvolensky, 2011), it was hypothesized that greater levels of PTSD symptoms would be associated with greater coping motives for alcohol use, but no other alcohol use motives, above and beyond the covariates of sex, trauma load, alcohol consumption, and non-coping alcohol use motives. It also was hypothesized that higher anxiety sensitivity would be associated with greater coping and conformity alcohol use motives, as has been found in past research in non-trauma exposed individuals (e.g., Stewart, Zvolensky, & Eifert, 2002). Finally, it was hypothesized that anxiety sensitivity would moderate an association between PTSD symptoms and coping motives for alcohol use, but no other drinking motives, such that greater PTSD symptoms would be associated with greater coping motives among those high, but not low, in anxiety sensitivity.
Author Manuscript
Method Participants Participants were 295 undergraduate students (74.0% women) participating in “Spit for Science,” a genetically informed university-wide study (hereafter referred to as the “parent
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 4
Author Manuscript
study”) investigating the progression and correlates of substance use and emotional health in college students at Virginia Commonwealth University (Dick et al., 2014). Individuals from the first three cohorts of the parent study were invited to determine eligibility for the current study if they endorsed possible interpersonal trauma history (via brief screener) and current alcohol use at any timepoint in the parent study. A comprehensive assessment of potentially traumatic event (PTE) exposure was conducted in the current study (described below). Participants from the parent study had completed 1–3 waves of assessment at the time of study recruitment, depending on their cohort and their ongoing participation in the follow-up sessions. Interested individuals completed an online screening item to determine whether they had used alcohol in the past 30 days. Individuals were excluded if they did not endorse past-30 day alcohol use. Measures
Author Manuscript Author Manuscript
The Traumatic Life Events Questionnaire (TLEQ; Kubany, 2000) is a 23-item self-report measure assessing whether and when participants experienced a range of PTEs (e.g., natural disaster, assault, accidents, illness/injury) and how many times each PTE occurred. For each event endorsed, participants are asked the number of times the event occurred. Participants are also asked to identify their most distressing event, when it first and last occurred, and rate the amount of distress the event causes on a scale ranging from “no distress” to “extreme distress.” The TLEQ has evidenced good test-retest reliability and good convergent validity with interview assessments of PTE (Kubany, 2000). The TLEQ was used in the current study to confirm the presence of a history of interpersonal PTE, defined as lifetime history of directly experiencing or witnessing physical assault, sexual assault, or unwanted sexual experiences (see Table 1 for a list of interpersonal PTEs included in the current study). The TLEQ also was used as a measure of trauma load, defined as the total number of PTE categories that an individual endorsed. The PTSD Checklist for DSM-5 (PCL-5; Weathers et al., 2013) is a 20-item self-report measure used to assess PTSD symptoms for individuals’ “most traumatic” PTE. Each item corresponds to the symptom criteria for PTSD in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association, 2013). Participants indicated the degree to which they have been bothered by a specific problem (e.g., “repeated, disturbing dreams of a stressful experience from the past”) in the past 30 days on a scale ranging from 0 (“not at all”) to 4 (“extremely”). The PCL-5 evidences good reliability and validity in young adult college samples (Blevins et al., 2015). The current study utilized the PCL-5 total score as a measure of PTSD symptoms (alpha=.94), and used a cut-off score of 38 to indicate a positive PTSD screen (Weathers et al., 2013).
Author Manuscript
The Anxiety Sensitivity Index-3 (ASI-3; Taylor et al. 2007) is an 18-item self-report measure that assesses the degree to which individuals fear anxiety and related sensations. It consists of three highly related subscales corresponding to the three sub-factors of anxiety sensitivity: physical concerns (e.g., “It scares me when my heart beats rapidly”), cognitive concerns (e.g., “It scares me when I’m unable to keep my mind on task”), and social concerns (e.g., “I worry that other people will notice my anxiety”). Respondents indicate the degree to which they believe each statement applies to them on a Likert scale from 0 (“very
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 5
Author Manuscript
little”) to 4 (“very much”). The current study utilized the ASI-3 total score as a measure of global anxiety sensitivity (alpha=.92). Current alcohol consumption was assessed via items querying past 30-day alcohol use quantity (i.e., “On the days that you drank during the past 30 days, how many drinks did you usually have each day?”) and frequency (i.e., “During the past 30 days, how many days did you drink one or more drinks of an alcoholic beverage?”). The measure was adapted from the Timeline Follow-back (TLFB; Sobell & Sobell, 1992). Past 30-day alcohol use quantity and frequency were included as covariates in the current study.
Author Manuscript
The Alcohol Use Disorders Identification Test (AUDIT; Babor, de la Fuente, Sauders, & Grant, 1992) is a 10-item self-report screening measure developed by the World Health Organization to identify individuals with alcohol problems. There is a large body of literature attesting to the psychometric properties of the AUDIT (e.g., Saunders, Aasland, Babor, de la Fuente, &Grant, 1993). The current study utilized the AUDIT as a descriptive measure of alcohol-related problems (alpha=.80). Individuals scoring an 8 or higher on the AUDIT likely meet criteria for at least “moderate” alcohol problems (Babor et al., 1992).
Author Manuscript
The Drinking Motives Questionnaire (DMQ), with inclusion of the DMQ-Revised Conformity items (Cooper, 1994) was administered to assess drinking motives. The DMQ indexes the frequency of drinking (i.e., almost never/never, sometimes, often, almost always) for four distinct motives: DMQ-Coping (e.g., “to forget your worries”), DMQ-Enhancement (e.g., “because you like the feeling”), DMQ-Conformity (e.g., “because your friends pressure you to drink”), and DMQ-Social (e.g., to be sociable”). The DMQ-R demonstrates good structural and criterion validity, as well as high internal consistency (Cooper, 1994; MacLean & Lecci, 2000). Due to significant kurtosis, the DMQ-Conformity subscale underwent a log transformation to improve normality (pre-transformation: skewness = 2.49, kurtosis = 7.35; post-transformation: skewness = 1.60, kurtosis = 2.19). No other subscales required transformation. Alphas in the current study ranged from .81-.85. Procedures
Author Manuscript
Overview of parent study—During students’ first week of freshman year, they received an email inviting them to participate in the “Spit for Science” study, which contained a link to an online survey with questions about personality and behavior, family, friends, and experiences growing up. Participants who initiated the survey consented online and completed a battery of assessments. After completion of the online survey, participants provided a salivary DNA sample and received compensation from a member of the research team. Participants were followed with annual surveys each spring throughout the duration of their college years. Full details on the study methods can be found in the “Spit for Science” study publication (Dick et al., 2014). Study data for the parent study and current study were collected and managed using REDCap (Research Electronic Data Capture), hosted at Virginia Commonwealth University (Harris et al., 2009). REDCap is a secure, web-based application for collecting and storing data.
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 6
Author Manuscript
Recruitment from the parent study—PTEs were assessed in the parent study via an abbreviated version of the Life Events Checklist (Gray, Litz, Hsu, & Lombardo, 2004), which assessed five different stressful life event categories: natural disasters, physical assaults, sexual assaults, other unwanted or uncomfortable sexual experiences, and transportation accidents. Past 30-day alcohol use frequency was assessed in the parent study on a 5-point scale ranging from 1 (“Never”) to 5 (“Four or more times a week”). Participants endorsing any PTE (with the exception of natural disaster, which was over-endorsed in the parent study) at any assessment point, as well as current alcohol use at any assessment point, were recruited for the current study. The current study recruited participants from the first three cohorts of the parent study (N=7,603; 61.1% women; 50.2% Caucasian, 19.5% Black, 16.3% Asian, 14% other), who enrolled between 2011–2013.
Author Manuscript Author Manuscript
Current Study Procedure—Potentially eligible participants received an email via REDCap from the parent study registry staff, introducing the current study (e.g., providing a brief study description and a link to a study website) and requesting permission to be contacted by the research team. Of the 3,570 initially contacted, 21.1% (n=755) made contact with the research team by completing a form indicating their interest in learning more about the study. Interested participants were sent a link to the online consent form, brief screening item (i.e., “Have you had one or more alcoholic drinks (e.g., beer, wine, liquor) in the past 30 days?”), and survey enrollment link. Seventy four percent of interested individuals (n=557) endorsed current alcohol use and consented to participate. After completing online informed consent procedures, they completed a battery of self-report and behavioral measures online via REDCap. Of the individuals who consented, 86.8% (n=501) of the sample completed all measures. Based on responses to the TLEQ, 295 participants (8.3% of those initially contacted) endorsed one or more instances of interpersonal PTE and were included in the current study analyses. Participants were paid $20 in cash for completing the study. The Institutional Review Board at Virginia Commonwealth University approved all study procedures for both the parent study and the current study. Data Analytic Plan
Author Manuscript
Analyses were conducted in SPSS Statistics 22. Zero-order correlations were examined among demographic and primary study variables. To address the primary study hypotheses, four hierarchical linear regressions were conducted. Prior to conducting the regression analyses, all continuous variables were converted to standard z-scores. The covariates of sex (1=male, 2=female), past 30-day alcohol use frequency and quantity, trauma load (i.e., number of trauma categories endorsed), and non-criterion DMQ subscales were entered at level 1 of the models. The main effects of PCL-5 total score and ASI-3 total score were entered at level 2. The interaction term (PCL-5*ASI-3) was entered at level 3. Criterion variables were: DMQ-coping, DMQ-social, DMQ-enhancement, and DMQ-conformity. The forms of any significant interactions were subsequently examined both graphically, as per recommendations from Cohen and Cohen (1983), and statistically (Holmbeck, 2002). First, on the basis of recommendations of Cohen and Cohen (pp. 323, 419), we examined the form of these interactions by inserting specific values for each predictor variable (1/2 SD above and below the mean) into the regression equation associated with the described analysis. Then, on the basis of recommendations of Holmbeck (2002), we conducted post hoc probing
Psychol Addict Behav. Author manuscript; available in PMC 2017 November 01.
Berenz et al.
Page 7
Author Manuscript
analyses to examine the significance of the simple slopes at each level of the moderator. Bonferroni correction was applied for the regression models to correct for multiple testing, with an adjusted p-value of .013 indicating statistical significance.
Results Descriptive Statistics and Zero-Order Correlations
Author Manuscript
See Table 1 for descriptive statistics. The sample was racially diverse (more than a third identifying as non-white) and predominately female. A range of PTEs was endorsed, with the most frequent interpersonal PTEs being threatened death or serious injury, witnessing family violence, and sexual abuse prior to age 13. High rates of accidental trauma also were endorsed, and participants endorsed a mean of 5 types of PTEs across all categories. The mean PCL-5 score for the overall sample was in the subclinical range for PTSD symptoms, with approximately one-fifth of the sample screening positive for PTSD. Approximately half of the sample scored an 8 or higher on the AUDIT, consistent with at least moderate alcohol problems. Table 2 presents correlations among the primary study variables. Female sex was associated with greater number of lifetime PTE types and greater PTSD symptoms, and male sex was associated with greater alcohol use quantity and frequency, as well as greater motivation to use alcohol for social, enhancement, and conformity reasons. Number of lifetime PTE types was positively associated with PTSD symptoms (PCL-5), anxiety sensitivity (ASI-3), and coping motives for alcohol use (DMQ-Coping), but no other drinking motives. PTSD symptoms (PCL-5) and anxiety sensitivity (ASI-3) were positively correlated with all drinking motives, and all drinking motives were positively correlated with one another.
Author Manuscript
PTSD symptoms, Anxiety Sensitivity, and Alcohol Use Motives
Author Manuscript
See Table 3 for regression output. The model accounted for 51.3% of variance in coping motives (DMQ-Coping; F(10, 293)=31.90, p
