Drinking motives and PTSD-related alcohol ...

Download PDF
1 downloads 0 Views 373KB Size Report
Comment
Aug 27, 2016 - Clinician-Administered PTSD Scale (CAPS). The CAPS (Blake et al., 1995) is a structured clinical interview that assesses symptoms of PTSD ...
Addictive Behaviors 64 (2017) 217–222

Contents lists available at ScienceDirect

Addictive Behaviors journal homepage: www.elsevier.com/locate/addictbeh

Drinking motives and PTSD-related alcohol expectancies among combat veterans☆ Meghan E. McDevitt-Murphy, Ph.D. a,b,⁎, Matthew T. Luciano, M.S. a,b, Jessica C. Tripp, M.S. a,b, Jasmine E. Eddinger, M.S. a a b

The University of Memphis, Department of Psychology, 202 Psychology Building, Memphis, TN 38152, United States Veterans Affairs Medical Center, 1030 Jefferson Avenue, Memphis, TN 38104, United States

H I G H L I G H T S • PTSD-alcohol expectancies were moderately correlated with scales measuring drinking to cope with anxiety and depression • Drinking to cope mediated the relationship between PTSD severity and AUDIT score • Positive PTSD-alcohol expectancies moderated the relationship between PTSD severity and AUDIT score.

a r t i c l e

i n f o

Article history: Received 21 October 2015 Received in revised form 12 August 2016 Accepted 23 August 2016 Available online 27 August 2016 Keywords: PTSD Veterans Alcohol expectancies Drinking motives Alcohol misuse

a b s t r a c t Introduction: Combat veterans are at increased risk for PTSD and alcohol misuse, and expectancies and motives for drinking may help explain the link between these comorbid issues. This investigation explored the relationships between PTSD symptoms, PTSD-related alcohol expectancies, motives for drinking, and alcohol consumption/misuse. Method: 67 veterans of Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/ OND) participated in this project. We examined correlations between PTSD severity, alcohol misuse, drinking motives, PTSD alcohol expectancies, and tested models of mediation and moderation. Results: Coping-anxiety drinking motives and positive PTSD-related alcohol expectancies were associated with alcohol misuse and alcohol-related consequences, but not with consumption. Each PTSD symptom cluster was associated with positive and negative PTSD alcohol expectancies, and coping-anxiety was specifically related to reexperiencing and avoidance. Drinking to cope mediated the relationship between PTSD symptoms and hazardous drinking. Moderation analyses showed that a positive relationship between PTSD severity and hazardous drinking existed among those with moderate and higher levels of positive PTSD-alcohol expectancies. Discussion: Our findings point to surprising, and in some cases complex, relationships between PTSD and alcohol use. Although related, PTSD alcohol expectancies and drinking motives seem to function differently in the relationship between PTSD and alcohol misuse. © 2016 Published by Elsevier Ltd.

1. Introduction 1.1. Comorbidity of PTSD and alcohol misuse Alcohol and other substance use disorders (AUD, SUD) are a significant public health problem among veterans. In particular, veterans

☆ This research was supported by the National Institutes of Health/National Institute on Alcohol Abuse and Alcoholism (K23AA016120) and by the Memphis VAMC Office of Research and Development. ⁎ Corresponding author at: 202 Psychology Building, Memphis, TN 38152, United States. E-mail address: [email protected] (M.E. McDevitt-Murphy).

http://dx.doi.org/10.1016/j.addbeh.2016.08.029 0306-4603/© 2016 Published by Elsevier Ltd.

returning from combat deployments in Afghanistan (Operation Enduring Freedom; OEF) and Iraq (Operation Iraqi Freedom or OIF and Operation New Dawn, or OND) are at higher risk for alcohol misuse than nondeployed veterans (Kelsall et al., 2015). In fact, recent epidemiological research suggests that as many as 36% of these returning combat veterans may engage in alcohol misuse (Burnett-Zeigler et al., 2011). Hazardous drinking among veterans has been linked to suicidal ideation (Gradus, Street, Suvak, & Resick, 2013), homelessness (Edens, Kasprow, Tsai, & Rosenheck, 2011), and disease burden (Possemato, Wade, Andersen, & Ouimette, 2010). In addition to these negative outcomes, OEF/OIF/OND veterans with alcohol misuse are often diagnosed with a comorbid mental health disorder, including PTSD (Petrakis, Rosenheck, & Desai, 2011). This

218

M.E. McDevitt-Murphy et al. / Addictive Behaviors 64 (2017) 217–222

presents a further challenge for improving veterans' health, since individuals with comorbid PTSD-SUD are likely to relapse faster, drink more, and use fewer problem-solving coping skills as compared to individuals with SUD only (Brown, Stout, & Mueller, 1996; Ouimette, Finney, & Moos, 1999). With comorbid PTSD and alcohol use disorders representing a significant issue for returning veterans, understanding the relationship between them has become increasingly important so that health care professionals may better develop interventions and prevent deleterious health complications. 1.2. Drinking motives and PTSD The self-medication model, which posits that individuals use substances to quell emotional distress (Khantzian, 1997), may partially explain the high co-occurrence of PTSD and alcohol misuse. To support this model, researchers have explored how drinking motives influence patterns of drinking in trauma-exposed populations. Drinking motives have been studied extensively outside of the realm of PTSD, and this work has identified that individuals' drinking may be motivated by a variety of reasons related to the context, and to internal states (Cooper, Frone, Russel, & Mudar, 1995; Cox & Klinger, 1988). Social and conformity motives reflect reasons for drinking that are related to one's social context while enhancement or coping motives refer to drinking that is prompted by a desire to alter one's internal state. In one study of heavy-drinking OEF/OIF veterans, those who met criteria for PTSD scored significantly higher on drinking motives scales for “coping with anxiety” and “coping with depression” compared with non-PTSD veterans. However, both groups scored similarly on scales measuring social, enhancement, and conformity motivations for drinking (McDevitt-Murphy, Fields, Monahan, & Bracken, 2015). Further, the PTSD group showed stronger associations between coping motives scales and aspects of alcohol misuse as compared to the non-PTSD group. In another study of drinking motives, Simpson, Stappenbeck, Luterek, Lehavot, and Kaysen (2014) examined the day-to-day variations of PTSD symptoms and alcohol use in a sample of adult trauma survivors. Findings from that study suggest that drinking motives may moderate this relationship, such that individuals who reported higher levels of coping motives showed larger increases in drinking in the wake of increased PTSD symptoms. In a study of individuals with severe mental illness (i.e. schizophrenia spectrum disorder or major mood disorder), coping motives mediated the relationship between three aspects of PTSD severity (total PTSD severity, hyperarousal symptoms, and avoidance symptoms) with alcohol consumption. Convivial drinking (i.e. drinking for celebration) only mediated the relationship between hyperarousal and alcohol consumption, suggesting that coping motives play an important role in the relationship between PTSD and alcohol consumption among individuals with severe mental illness (O'Hare & Sherrer, 2011). In a mixed sample of civilians and veterans, after adjusting for the effects of depression, PTSD symptoms were significantly associated with coping motives, and PTSD was also associated with enhancement motives among men. Coping motives predicted higher alcohol consumption quantity for women, while enhancement motives predicted alcohol consumption quantity for both women and men (Lehavot, Stappenbeck, Luterek, Kaysen, & Simpson, 2014). 1.3. PTSD and alcohol expectancies A construct closely related to drinking motives, alcohol expectancies, may help to further explain hazardous drinking among veterans with PTSD. Alcohol expectancies are the cognitive and behavioral effects that an individual believes will occur because of their drinking (Leigh, 1989). In laboratory studies, people who endorse positively-valenced expectancies (e.g. that alcohol will enhance social skills) have been found to drink more frequently and consume larger quantities of alcohol (Carey, 1995; Fromme, Stroot, & Kaplan, 1993; Pabst, Kraus, Piontek, Mueller, & Demmel, 2014). Although there has been little research

regarding alcohol expectancies in veterans, it may be particularly relevant to understand how PTSD-related alcohol expectancies may contribute to drinking patterns in this population. PTSD-related alcohol expectancies are the beliefs that individuals hold about how alcohol will affect their symptoms of PTSD. In the initial work to validate the PTSD Alcohol Expectancies Questionnaire (PAEQ), Norman, Inaba, Smith, and Brown (2008) examined Vietnam veterans' endorsement of positive expectancies (i.e. the perception that alcohol would ameliorate specific PTSD symptoms) and negative expectancies (i.e. the perception that alcohol would worsen specific PTSD symptoms). The results of that initial study indicated that veterans with PTSD did not endorse more positive expectancies than veterans without PTSD. This finding suggested that veterans with PTSD did not necessarily expect their symptoms to improve as a result of drinking, suggesting the relationship between PTSD and hazardous drinking may be more complex than the self-medication model implies. To date, few peer-reviewed articles have been published using the PAEQ. Vik, Islam-Zwart, and Ruge (2008) conducted a study using an earlier version of the measure that examined the influence of alcohol expectancies on PTSD symptom reduction. The results of that study indicated that PTSD-specific alcohol expectancies did not moderate the relationship between PTSD and drinking, but that expectancies about numbing symptoms were correlated with alcohol consumption and subsequent consequences. Additionally, Shaumberg et al. (2015) found that impulsivity moderated the relationship between positive PTSD-related alcohol expectancies and alcohol use in a sample of participants from a residential substance use treatment facility. Negative expectancies, however, did not relate to impulsivity or alcohol use severity. No studies have yet taken a fine-grained approach to examining relationships between PTSD-alcohol expectancies, specific PTSD symptom dimensions, and specific aspects of drinking. 1.4. Current study In this investigation, we explored two constructs that may relate to drinking in a sample of combat veterans: drinking motives and PTSD-alcohol related expectancies. The goal was to demonstrate the relations among these constructs, and to explore how both of these constructs related to PTSD symptoms and to alcohol consumption and misuse. In a prior study of veterans, those with PTSD showed higher levels of coping motives than heavy-drinking veterans without PTSD, but similar levels of other types of motives. In the present exploratory study, we sought to extend that prior work in two ways. First, the present sample is not limited to hazardous drinkers only, and second, we also investigated the role of PTSD-related alcohol expectancies. 2. Method 2.1. Participants We recruited 67 OEF/OIF/OND veterans (17.9% female) from the Memphis Veterans Affairs Medical Center (VAMC). The sample was racially diverse with 42.4% (n = 28) identifying as Caucasian and 50.7% of the sample (n = 34) identifying as African American. The mean age of participants was 36.55 years (SD = 10.70), with participants reporting ages between 21 and 60. Veterans were represented from the Army (61.4%), Air Force (15.9%), Marine Corps (9.1%), Navy (6.8%), and National Guard (6.8%). The average length of deployment was 12.10 months (SD = 8.80). More information on the sample can be found on Table 1. 2.2. Procedure Veterans were approached in waiting areas around the Memphis VAMC and invited to participate in this research study. Recruitment was limited to those veterans who served in Operations Enduring

M.E. McDevitt-Murphy et al. / Addictive Behaviors 64 (2017) 217–222 Table 1 Demographic characteristics and descriptive statistics for the sample (N = 67).

Race White Black Hispanic Asian Gender Male Female Age, in years Total CAPS score PAEQ (positive) PAEQ (negative) DMQ-R Social Coping-anxiety Coping-depression Enhancement Conformity AUDIT Average number of drinks/week Total # days binged

n or M

% or SD

28 34 3 3

41.8% 50.7% 4.5% 4.5%

55 12 36.55 52.92 32.98 29.76

82.1 17.9 10.70 32.97 14.27 12.87

2.39 1.92 1.77 1.79 1.15 4.03 4.24 1.09

1.25 1.04 1.17 0.95 0.42 5.69 8.64 3.08

Note. DMQ-R = Drinking Motives Questionnaire, Revised. CAPS = Clinician-Administered PTSD Scale; AUDIT = Alcohol Use Disorders Identification Test. PAEQ = PTSD Alcohol Expectancies Questionnaire. For the PAEQ, N = 52.

Freedom, Iraqi Freedom, or New Dawn. Recruitment efforts were mainly focused on primary care clinics that saw a high concentration of OEF/ OIF/OND veterans. After consenting to the study, participants completed a brief set of measures at that time, and then scheduled appointments to complete a longer assessment battery over the course of two sessions. Participants were compensated with $20 for each appointment. Institutional Review Boards at both the Memphis VAMC and The University of Memphis approved this study. 2.3. Measures 2.3.1. Clinician-Administered PTSD Scale (CAPS) The CAPS (Blake et al., 1995) is a structured clinical interview that assesses symptoms of PTSD using DSM-IV criteria. Responses are rated on a 5-point scale for frequency (0 = None to 4 = Most/all of the time) and intensity (0 = absent to 4 = extreme/incapacitating) of symptoms. For the purposes of this study, frequency and intensity ratings were summed, creating an overall severity score and individual symptom cluster scores. For all analyses that used the PAEQ, we included only participants who were experiencing at least a minimal level of PTSD symptoms, and we set that criteria at a CAPS total severity score of at least 15 (n = 52). This score is within the score range described as “minimal/ asymptomatic” in the CAPS manual. According to a review by Weathers et al. (2001), the CAPS has exhibited excellent reliability and validity in both veteran and civilian samples. Using the 34 frequency and intensity items, our study showed strong evidence of internal consistency with alpha of 0.962. 2.3.2. Modified Drinking Motives Questionnaire, Revised (DMQ-R) The DMQ-R, developed by Grant, Stewart, O'Connor, Blackwell, and Conrod (2007), is a 28-item list of motivations for drinking alcohol. Respondents are asked to use a scale ranging from 1 (almost never/never) to 5 (almost always/always) reflecting how often he or she may drink for each reason. Items in the questionnaire can be loaded onto five distinct subscales including social motives (e.g. “Because it is what most of my friends do when we get together”; α = 0.919), coping with anxiety motives (e.g. “To reduce my anxiety”; α = 0.841), coping with depression motives (e.g. “To stop me from being so hopeless about the future”; α = 0.965), enhancement motives (e.g. “To get a high”; α = 0.847), and conformity motives (e.g. “To fit in with a group I like”; α = 0.844).

219

2.3.3. PTSD-Alcohol Expectancies Questionnaire (PAEQ) The PAEQ, developed by Norman et al. (2008), is a 27-item questionnaire assessing self-reported beliefs about the effects of alcohol use on one's own PTSD symptoms. Individual items were based on a 5-point scale ranging from 1 (strongly disagree) to 5 (strongly agree) regarding a statement about how much alcohol affected their specific symptoms. Items represent two scales – the positive expectancies scale, which indicates the level that individuals believe alcohol to ameliorate PTSD symptoms (e.g. “My bad dreams would decrease after a few drinks”) and the negative expectancies scale, which indicates the level that individuals believe alcohol to worsen PTSD symptoms (e.g. “After a few drinks I would be more angry or on edge”). Questions were developed based on DSM-IV diagnostic criteria for PTSD. Internal consistency of the PAEQ in the current sample was excellent (positive scale α = 0.973; negative scale α = 0.971). 2.3.4. Timeline Follow Back (TLFB) Developed by Sobell and Sobell (1996), this measure is a calendarbased tool that collects information on alcohol quantity and frequency over the past month using anchor events to assist with respondents' recall. Trained interviewers gauge how many standard drinks a person consumed on a particular day and the duration of the drinking episode. Data from the TLFB were used to calculate several metrics of alcohol use, including the average number of drinks per week, and the total number of binge episodes (days on which the participant reported drinking at least 4 standard drinks for women, or 5 for men) in the previous 30 days. The TLFB has shown strong reliability in psychiatric outpatient settings (Carey, Carey, Maisto, & Henson, 2006). 2.3.5. Alcohol Use Disorders Identification Test (AUDIT) The AUDIT (Babor, Higgins-Biddle, Saunders, & Monteiro, 2001) is a 10-item screening measure of problematic alcohol use with individual items ranging from 0 to 4. Scores of 8 and higher are thought to reflect hazardous alcohol use. It has demonstrated strong psychometric characteristics in a sample of veterans (Bush, Kivlahan, McDonell, Fihn, & Bradley, 1998). For the current analyses, a total score was calculated to determine the overall degree of harmful alcohol use. Cronbach's alpha in this sample was strong (α = 0.827). 2.4. Data analysis plan Prior to conducting analyses we corrected outliers from the sample using recommendations outlined by Tabachnick and Fidell (2007). We first examined bivariate correlations among drinking motives, PTSD-alcohol expectancies, PTSD severity, alcohol consumption, and alcohol misuse. Next, based on these bivariate results, we tested a mediation model, exploring if coping motives mediated the relationship between PTSD severity (CAPS total score) and hazardous drinking (AUDIT score). Finally, we tested moderation models which specified the Positive and Negative subscales of the PAEQ as moderators of the relationship between PTSD and hazardous drinking (AUDIT). For both the moderation and mediation analyses, we controlled for alcohol consumption in our models to reduce the likelihood that consumption served as a confound, accounting for unique variance in AUDIT score. For analyses using the PAEQ, we used a subset of the population that endorsed a minimal level of PTSD symptoms (n = 52). 3. Results 3.1. Descriptive statistics Demographic characteristics and means and standard deviations for each of the measures are presented in Table 1. Thirty-two veterans (47.8% of the sample) met criteria for PTSD using the Frequency of 1/Intensity of 2 (F1/I2) scoring rule on the CAPS (Weathers, Ruscio, & Keane, 1999). This rule specifies that symptoms are considered “present” when

220

M.E. McDevitt-Murphy et al. / Addictive Behaviors 64 (2017) 217–222

the symptom frequency is rated at least 1 and intensity is rated at least 2 (both on scales ranging from 0 to 4). The diagnostic criteria for PTSD are met if there is a positive rating for symptoms consistent with the DSMIV algorithm of 1 re-experiencing symptom, 3 avoidance and numbing symptoms, and 2 hyperarousal symptoms. The PTSD group had a mean CAPS total score of 77.84 (SD = 20.71) and the non-PTSD group had a mean score of 29.09 (SD = 23.91).

2013). We controlled for quantity of alcohol consumption (average weekly drinking), and found that the overall model was significant, (r = 0.727; F = 20.96; p = 0.0067) and that drinking to cope mediated the relationship between PTSD severity (total CAPS score) and hazardous drinking, as measured by the AUDIT (β = 0.168, SE = 0.095, 95% CI = 0.036–0.42). 3.4. Moderation analyses

3.2. Correlations between variables We examined correlations among measures of PTSD severity, alcohol use, drinking motives, and PTSD-related alcohol expectancies. Total PTSD severity was significantly correlated with both of the coping motives scales and with both subscales of the PAEQ. The PAEQ-Positive scale (reflecting an expectation of symptom alleviation from alcohol) was significantly correlated with AUDIT total score. The PAEQ-Negative subscale (reflecting an expectation of symptom worsening with alcohol consumption) was not significantly correlated with any aspect of alcohol consumption or with AUDIT total score. With respect to drinking motives, we found that motives reflecting enhancement, and drinking to cope with anxiety were significantly correlated with alcohol quantity, frequency of binge drinking, and total AUDIT score. The coping-depression DMQ-R scale was correlated with frequency of binge drinking and AUDIT score. The PAEQ scales and the DMQ-R scales showed small to moderate correlations with each other. Detailed information about these analyses can be found on Table 2. Table 3 displays correlational analyses exploring relations between the PTSD symptom clusters and the PAEQ and DMQ-R subscales (see Table 3). All of the PTSD symptom clusters were positively correlated with negative PTSD alcohol expectancies. The coping-anxiety and coping-depression motives scales showed significant associations with several aspects of PTSD symptoms. Interestingly, the hyperarousal symptoms were not significantly correlated with coping-anxiety motives. The social and conformity motives were not significantly correlated with any aspect of PTSD severity.

The pattern of correlational findings raised the possibility that PTSDalcohol expectancies could be moderating the relations between PTSD symptoms and hazardous drinking, given that: a) the correlations between PTSD and hazardous drinking were not statistically significant, b) positive PTSD-alcohol expectancies showed small magnitude correlations with PTSD symptoms, and c) negative expectancies showed slightly stronger correlations. We conducted two moderation analyses, using each of the PAEQ scales (Positive and Negative) as moderators between CAPS total and AUDIT severity in those who scored at least 15 on the CAPS (n = 52). Average weekly alcohol consumption was added as covariate for both of these analyses to reduce the likelihood that alcohol consumption might be confounding the results. Both variables were automatically centered through the PROCESS macro in order to control for multicollinearity. A 95% confidence interval was used to determine significance in all analyses. The interaction between CAPS total severity and PAEQ-Positive was significant in predicting AUDIT severity (β = 0.004, SE = 0.002, 95% CI = 0.0004 to 0.008), suggesting that PAEQ-Positive functions as a moderator of the relationship between PTSD and hazardous drinking. Simple slope analyses indicated that this relationship was significant (p b 0.05) at moderate (B = 0.056), and high (B = 0.113), but not low levels of positive PTSD-alcohol expectancies. These results are depicted in Fig. 1. The interaction between CAPS total and Negative PAEQ was not significant in predicting AUDIT severity (β = 0.00, SE = 0.002, 95% CI = −0.004 to 0.82), as depicted in Fig. 2. 4. Discussion

3.3. Mediation analyses Given the positive correlations between PTSD severity scores, coping motives, and hazardous drinking, we hypothesized that coping-depression and coping-anxiety motives may function as mediators of the relation between PTSD and hazardous drinking. There was a high degree of correlation between the two DMQ-R-Coping scales (r = 0.824), so we created a composite drinking to cope score, which reflected an average of the scores on the DMQ-R scales reflecting drinking to cope with depression and drinking to cope with anxiety. We conducted a mediation analysis to test the indirect effect of CAPS on AUDIT total through DMQR-Coping in a mediation model using the PROCESS macro (Hayes,

In this study, we investigated the role of the constructs of drinking motives and PTSD-alcohol expectancies in understanding the relations among PTSD and alcohol misuse in a sample of veterans. There were several surprising findings from analyses on the associations between PTSD, alcohol misuse, motives for drinking, and PTSD-alcohol related expectancies. First, it was unexpected that there was not a significant relationship among PTSD and alcohol misuse in the sample, as has been found in prior research (e.g., McDevitt-Murphy et al., 2010; Blanco et al., 2013). It is noteworthy that the mean AUDIT score in the sample was low, and the fact that this was a low-risk sample (i.e., there were no inclusion criteria for the study related to showing symptoms or

Table 2 Correlations between drinking motives, PTSD-alcohol expectancies, and PTSD with alcohol consumption, and PTSD severity (N = 67).

Variable DMQ-R Social Coping-anxiety Coping-depression Enhancement Conformity PAEQ Positive Negative CAPS total

Average number drinks/week

Total # days binged

AUDIT score

0.25⁎ 0.34⁎⁎ 0.23 0.33⁎⁎

0.26⁎ 0.34⁎⁎ 0.26⁎ 0.35⁎⁎

0.14 0.50⁎⁎ 0.58⁎⁎ 0.41⁎⁎

−0.07

−0.07

−0.02

0.03 0.07 −0.05

0.05 0.05 −0.02

0.31⁎ 0.12 0.20

DMQ-R Social

DMQ-R Coping-anxiety

DMQ-R Coping-depression

DMQ-R Enhance.

DMQ-R Conform.

0.37⁎⁎ 0.30⁎ −0.07

0.42⁎⁎ 0.32⁎ 0.30⁎

0.37⁎⁎ 0.22 0.42⁎⁎

0.37⁎⁎ 0.25 0.21

0.27 0.13 0.03

CAPS total

0.28⁎ 0.44⁎⁎

Note. Across analyses, n ranged from 63 to 67 due to missing data. DMQ-R = Drinking Motives Questionnaire, Revised. CAPS = Clinician-Administered PTSD Scale; AUDIT = Alcohol Use Disorders Identification Test; PAEQ = PTSD Alcohol Expectancies Questionnaire. For analyses using the PTSD-Alcohol Expectancies Questionnaire, N = 51. ⁎ p ≤ 0.05. ⁎⁎ p ≤ 0.01.

M.E. McDevitt-Murphy et al. / Addictive Behaviors 64 (2017) 217–222

221

Table 3 Correlations between PTSD criterion B, C, D, avoidance symptoms, and numbing symptoms with drinking expectancies and motives (N =65).

CAPS symptom clusters B – reexperiencing C – avoidance and numbing Avoidance Numbing D – hyperarousal

PAEQ-Positive

PAEQ-Negative

DMQ-R Social

DMQ-R Coping-anxiety

DMQ-R Coping-depression

DMQ-R Enhancement

DMQ-R Conformity

0.22 0.26 0.33⁎ 0.18 0.26

0.30⁎⁎ 0.43⁎⁎ 0.37⁎⁎ 0.39⁎⁎ 0.43⁎⁎

−0.08 −0.06 0.04 −0.12 −0.12

0.30⁎ 0.30⁎ 0.34⁎⁎ 0.22 0.16

0.45⁎⁎ 0.37⁎⁎ 0.40⁎⁎ 0.30⁎ 0.29⁎

0.25⁎ 0.20 0.29⁎ 0.12 0.09

0.01 0.08 0.15 0.04 −0.03

Note. CAPS = Clinician-Administered PTSD Scale; PAEQ = PTSD Alcohol Expectancies Questionnaire, DMQ-R = Drinking Motives Questionnaire, Revised. For analyses using the PAEQ, N = 51. ⁎ p ≤ 0.05. ⁎⁎ p ≤ 0.01.

evidence of heavy drinking) may be one reason for the lack of association. It was also surprising that the positive and negative alcohol expectancies scales were not more strongly correlated with the motives scales. AUDIT score and binge drinking frequency were significantly associated with several aspects of drinking motives, including drinking to cope with anxiety and drinking to cope with depression, as well as enhancement (which was correlated with AUDIT but not binge frequency). The coping drinking motives scales were also correlated with each symptom cluster of PTSD and enhancement motives were correlated with re-experiencing and avoidance motives. These patterns suggest that a desire to improve one's internal state (reducing symptoms of PTSD, or enhancing pleasant feelings) may influence drinking. Additionally PTSD symptoms may influence those motives for drinking. Inspecting the correlational findings related to PTSD-alcohol expectancies, it is clear that neither scale showed a bivariate relationship with alcohol variables. The PAEQ showed a curious pattern of correlations with PTSD variables. The negative expectancies scale (reflecting beliefs that PTSD symptoms would worsen after consuming alcohol) was correlated with each aspect of PTSD, while the positive scale was correlated only with avoidance symptoms. Overall, the patterns of correlational findings suggested that beliefs (i.e., motives or expectancies) that ostensibly seemed likely to link PTSD symptoms and alcohol use/misuse did not do so in a straightforward way. This led us to speculate about the role of coping motives for drinking as a possible mediator between PTSD and alcohol misuse, and about PTSD-alcohol expectancies as a possible moderator. In mediation analyses, we found that motives reflecting drinking to cope with depression and anxiety mediated the relationship between

PTSD symptoms and hazardous drinking. This finding provides some additional explanation about the conditions under which individuals with PTSD may develop a hazardous pattern of drinking. In moderation analyses, we found that positive PTSD-alcohol expectancies (the PAEQPositive subscale, reflecting a belief that PTSD symptoms would be ameliorated by alcohol consumption) moderated the relationship between PTSD severity and hazardous drinking. Among individuals with a higher level of positive expectancies, there was a positive relationship between PTSD and hazardous drinking, a relationship that was absent among those with lower scores on the PAEQ-positive scale. In sum, the findings from this exploratory study suggest that more research on these important constructs is warranted. These cognitive variables appear to play a role at different points in the relationship between PTSD and hazardous drinking. The PTSD alcohol expectancies may reflect previously held beliefs that could set the stage for substance abuse in an individual following the onset of PTSD. It is also possible that these expectancies may be malleable, in the context of an intervention. Drinking to cope, however, reflects a motivational state with emotional and cognitive components. Coping drinking motives show a correlation with PTSD severity, suggesting that among those who are more symptomatic, the drive to soothe one's distress with alcohol may be more rigidly held. 4.1. Limitations In interpreting these findings, some important limitations are worth noting. First, this study was cross-sectional in nature. This design limits the analyses by preventing exploration of the temporal implications of our findings. Second, female veterans were underrepresented in this

7

9 8

6

7

AUDIT severity

AUDIT severity

5 6 5 4 3

4 3 2

2 1

1

0

0 Low

Average

High

Low

PAEQ Positive Low

PAEQ Positive Average

PAEQ Positive High

Fig. 1. PAEQ-Positive subscale as a mediator of the relationship between CAPS total and AUDIT score.

Average

High

CAPS total

CAPS total PAEQ Negative Low

PAEQ Negative Average

PAEQ Negative High

Fig. 2. PAEQ-Negative subscale as a mediator of the relationship between CAPS total score and AUDIT score.

222

M.E. McDevitt-Murphy et al. / Addictive Behaviors 64 (2017) 217–222

sample, preventing stratification of results by gender. Third, our PTSD measure was based on the DSM-IV, and thus the full range of PTSD symptoms as it is currently conceptualized was not reflected. Finally, the sample was small, and we did not have the power to detect more subtle effects. Given our small sample size, and the available literature demonstrating gender differences in drinking patterns, future research should make use of a larger and more gender balanced sample size. 4.2. Conclusions In sum, the present findings suggest that drinking motives and alcohol-related expectancies may offer clues to understanding the complex relations between PTSD and alcohol misuse. Positive expectancies about the effect of alcohol on one's PTSD symptoms may serve as a risk factor for hazardous drinking, and may reflect a priori beliefs about how alcohol affects PTSD symptoms. Coping motives for drinking are associated with high-risk drinking, and are more strongly endorsed by veterans with more severe PTSD symptoms. Both of these cognitive factors may be important for clinicians to assess in order to plan intervention strategies in this complex population. Role of funding sources Funding for this study was provided by NIAAA Grant K23AA016120. NIAAA had no role in the study design, collection, analysis, or interpretation of the data, writing the manuscript, or the decision to submit the paper for publication. Contributors Meghan McDevitt-Murphy designed the original study, conceptualized the current paper, planned the analyses, and wrote parts of the manuscript. Matthew Luciano conducted statistical analyses and contributed to writing and editing the manuscript. Jasmine Eddinger and Jessica Tripp contributed to writing and editing the manuscript. Conflicts of interest None declared. Acknowledgements Funding for this study was provided by NIAAA Grant K23AA016120. We also acknowledge the support of the Memphis VAMC Office of Research and Development.

References Babor, T. F., Higgins-Biddle, J. C., Saunders, J. B., & Monteiro, M. G. (2001). The Alcohol Use Disorders Identification Test: Guidelines for use in primary 2nd ed. Geneva, Switzerland: World Health Organization. Blake, D. D., Weathers, F. W., Nagy, L. M., Kaloupek, D. G., Gusman, F. D., Charney, D. S., & Keane, T. M. (1995). The development of a clinician-administered PTSD scale. Journal of Traumatic Stress, 8, 75–90. http://dx.doi.org/10.1023/a:1007781909213. Blanco, C., Xu, Y., Brady, K., Pérez-Fuentes, G., Okuda, M., & Wang, S. (2013). Comorbidity of posttraumatic stress disorder with alcohol dependence among US adults: Results from national epidemiological survey on alcohol and related conditions. Drug and Alcohol Dependence, 132, 630–638. http://dx.doi.org/10.1016/j.drugalcdep.2013.04. 016. Brown, P. J., Stout, R. L., & Mueller, T. (1996). Posttraumatic stress disorder and substance abuse relapse among women: A pilot study. Psychology of Addictive Behaviors, 10, 124–128. Burnett-Zeigler, I., Ilgen, M., Valenstein, M., Zivin, K., Gorman, L., Blow, A., & Chermack, S. (2011). Prevalence and correlates of alcohol misuse among returning Afghanistan and Iraq veterans. Addictive Behaviors, 36, 801–806. http://dx.doi.org/10.1016/j. addbeh.2010.12.032. Bush, K., Kivlahan, D. R., McDonell, M. B., Fihn, S. D., & Bradley, K. A. (1998). The AUDIT alcohol consumption questions (AUDIT-C): An effective brief screening test for problem drinking. Ambulatory Care Quality Improvement Project (ACQUIP). Alcohol Use Disorders Identification Test. Archives of Internal Medicine, 158(16), 1789–1795. Carey, K. B. (1995). Alcohol-related expectancies predict quantity and frequency of heavy drinking among college students. Psychology of Addictive Behaviors, 9, 236–241. http://dx.doi.org/10.1037/0893-164X.9.4.236. Carey, K. B., Carey, M. P., Maisto, S. A., & Henson, J. M. (2006). Brief motivational interventions for heavy college drinkers: A randomized controlled trial. Journal of Consulting and Clinical Psychology, 74, 943–954. http://dx.doi.org/10.1037/0022-006X.74.5.943. Cooper, M. L., Frone, M. R., Russel, M., & Mudar, P. (1995). Drinking regulates positive and negative emotions: A motivational model of alcohol use. Journal of Personality and Social Psychology, 69, 990–1005. http://dx.doi.org/10.1037/0022-3514.69.5.990.

Cox, W. M., & Klinger, E. (1988). A motivational model of alcohol use. Journal of Abnormal Psychology, 97, 168–180. http://dx.doi.org/10.1037/0021-843X.97.2.168. Edens, E. L., Kasprow, W., Tsai, J., & Rosenheck, R. A. (2011). Association of substance use and VA service-connected disability benefits with risk of homelessness among veterans. The American Journal on Addictions, 20, 412–419. http://dx.doi.org/10.1111/j. 1521-0391.2011.00166.x. Fromme, K., Stroot, E. A., & Kaplan, D. (1993). Comprehensive effects of alcohol: Development and psychometric assessment of a new expectancy questionnaire. Psychological Assessment, 5, 19–26. http://dx.doi.org/10.1037/1040-3590.5.1.19. Gradus, J. L., Street, A. E., Suvak, M. K., & Resick, P. A. (2013). Predictors of suicidal ideation in a gender-stratified sample of OEF/OIF veterans. Suicide and Life-threatening Behavior, 43, 574–588. http://dx.doi.org/10.1111/sltb.12040. Grant, V. V., Stewart, S. H., O'Connor, R. M., Blackwell, E., & Conrod, P. J. (2007). Psychometric evaluation of the five-factor Modified Drinking Motives Questionnaire — Revised in undergraduates. Addictive Behaviors, 32, 2611–2632. http://dx.doi.org/10. 1016/j.addbeh.2007.07.004. Hayes, A. F. (2013). Introduction to mediation, moderation, and conditional process analysis: A regression-based approach. New York, NY, US: Guilford Press. Kelsall, H., Wijesinghe, M., Creamer, M., McKenzie, D., Forbes, A., Page, M., & Sim, M. (2015). Alcohol use and substance use disorders in the Gulf War, Afghanistan, and Iraq War veterans compared with nondeployed military personnel. Epidemiologic Reviews, 37, 38–54. http://dx.doi.org/10.1093/epirev/mxu014. Khantzian, E. J. (1997). The self-medication hypothesis of substance use disorders: A reconsideration and recent applications. Harvard Review of Psychiatry, 4(5), 231–244. Lehavot, K., Stappenbeck, C. A., Luterek, J. A., Kaysen, D., & Simpson, T. L. (2014). Gender differences in relationships among PTSD severity, drinking motives, and alcohol use in a comorbid alcohol dependence and PTSD sample. Psychology of Addictive Behaviors, 28, 42–52. http://dx.doi.org/10.1037/a0032266. Leigh, B. C. (1989). In search of the seven dwarves: Issues of measurement and meaning in alcohol expectancy research. Psychological Bulletin, 105, 361–373. http://dx.doi.org/ 10.1037/0033-2909.105.3.361. McDevitt-Murphy, M. E., Williams, J. L., Bracken, K. L., Fields, J. A., Monahan, C. J., & Murphy, J. G. (2010). PTSD symptoms, hazardous drinking, and health functioning among U.S.OEF/OIF veterans presenting to primary care. Journal of Traumatic Stress, 23, 108–111. McDevitt-Murphy, M. E., Fields, J. A., Monahan, C. M., & Bracken, K. L. (2015). Drinking motives among heavy drinking veterans with and without posttraumatic stress disorder. Addiction Research and Theory, 23, 148–155. http://dx.doi.org/10.3109/ 16066359.2014.949696. Norman, S. B., Inaba, R. K., Smith, T. L., & Brown, S. A. (2008). Development of the PTSDalcohol expectancy questionnaire. Addictive Behaviors, 33, 841–847. http://dx.doi. org/10.1016/j.addbeh.2008.01.003. O'Hare, T., & Sherrer, M. (2011). Drinking motives as mediators between PTSD symptom severity and alcohol consumption in persons with severe mental illnesses. Addictive Behaviors, 36, 465–469. http://dx.doi.org/10.1016/j.addbeh.2011.01.006. Ouimette, P. C., Finney, J. W., & Moos, R. H. (1999). Two-year posttreatment functioning and coping of substance abuse patients with posttraumatic stress disorder. Psychology of Addictive Behaviors, 13, 105–114. http://dx.doi.org/10.1037/0893164X. 13.2.105. Pabst, A., Kraus, L., Piontek, D., Mueller, S., & Demmel, R. (2014). Direct and indirect effects of alcohol expectancies on alcohol-related problems. Psychology of Addictive Behaviors, 28, 20–30. http://dx.doi.org/10.1037/a0031984. Petrakis, I. L., Rosenheck, R., & Desai, R. (2011). Substance use comorbidity among veterans with posttraumatic stress disorder and other psychiatric illness. The American Journal on Addictions, 20, 185–189. http://dx.doi.org/10.1111/j.15210391.2011. 00126.x. Possemato, K., Wade, M., Andersen, J., & Ouimette, P. (2010). The impact of PTSD, depression, and substance use disorders on disease burden and health care utilization among OEF/OIF veterans. Psychological Trauma: Theory, Research, Practice, and Policy, 2, 218–223. http://dx.doi.org/10.1037/a0019236. Shaumberg, K., Vinci, C., Raiker, J., Mota, N., Jackson, M., Whalen, D., & Coffey, S. (2015). PTSD-related alcohol expectancies and impulsivity interact to predict alcohol use severity in a substance dependent sample with PTSD. Addictive Behaviors, 41, 41–45. http://dx.doi.org/10.1016/j.addbeh.2014.09.022. Simpson, T. L., Stappenbeck, C. A., Luterek, J. A., Lehavot, K., & Kaysen, D. L. (2014). Drinking motives moderate daily relationships between PTSD symptoms and alcohol use. Journal of Abnormal Psychology, 123, 237–247. http://dx.doi.org/10.1037/a0035193. Sobell, L. C., & Sobell, M. B. (1996). Timeline followback users guide: A calendar method for assessing alcohol and drug use. Toronto, Canada: Addition Research Foundation. Tabachnick, B. G., & Fidell, L. S. (2007). Using multivariate statistics (5th ed ). Boston, MA: Allyn & Bacon/Pearson Education. Vik, P. W., Islam-Zwart, K. A., & Ruge, L. N. (2008). Application of the PTSD-alcohol expectancy questionnaire (P-AEQ) to sexually assaulted college women. Addiction Research and Theory, 16, 585–594. http://dx.doi.org/10.1080/16066350701867273. Weathers, F. W., Keane, T. M., & Davidson, J. R. (2001). Clinician‐Administered PTSD Scale: A review of the first ten years of research. Depression and Anxiety, 13, 132–156. http:// dx.doi.org/10.1037/t00072-000. Weathers, F. W., Ruscio, A. M., & Keane, T. M. (1999). Psychometric properties of nine scoring rules for the clinician-administered posttraumatic stress disorder scale. Psychological Assessment, 11, 124–133. http://dx.doi.org/10.1002/jts.20003.