(PS1-21) Drinking to Cope as a Moderator of CBT-I Effects on PTSD Symptoms Among Veterans

Introduction: The comorbidity of Alcohol Use Disorder (AUD) and Post-Traumatic Stress Disorder (PTSD) is highly prevalent among veterans. The co-occurrence of these disorders negatively impacts one’s overall health and well-being, which can lead to maladaptive coping mechanisms such as continued drinking. Cognitive Behavioral Therapy (CBT) has been effective in reducing drinking to cope. CBT for insomnia (CBT-I) has also been effective in reducing sleep disturbance among veterans and those with AUD and/or PTSD. However, few studies have examined the extent to which drinking to cope moderates CBT-I effects on PTSD. Theoretically, effective treatment of insomnia could reduce or eliminate one motive for alcohol use (i.e., to improve sleep), which may also impact symptoms of PTSD. As such, we hypothesized that CBT-I would be more effective in reducing PTSD symptoms among those who report frequently drinking to cope.

Methods:  Heavy-drinking Veterans with insomnia (N=51; 82% men; 86% White; mean age=38.8y) were randomly assigned to CBT-I (five weekly sessions; n=26) or sleep hygiene control (SH; n=25). Participants completed the Modified Drinking Motives Questionnaire-Revised (DMQ-R) at baseline, and responses to the “drinking to cope” items were summed to create a total score. The PTSD Checklist for the DSM-5 (PCL-5) was administered at baseline, post-treatment, and 6-week follow-up. Multiple regression was used to test drinking to cope as a moderator of CBT-I effects on symptoms of PTSD, controlling for baseline PTSD symptoms. Follow-up tests of simple slopes were conducted at high (M=3.43) and low (M=1.28) levels of drinking to cope.

Results:  CBT-I participants reported greater decreases in PTSD from baseline to follow-up than sleep hygiene participants, but between-group differences were not statistically significant (CBT-I average scores at baseline=26.80, post-treatment=14.30, follow-up=18.90; SH mean at baseline=25.89, post-treatment=28.06, follow-up=22.78). Drinking to cope moderated the effects of CBT-I on symptoms of PTSD at post-treatment (B=-10.28, SE=4.92, p=.04), but not at follow-up (B=-3.61, SE=5.02, p=.48). At post-treatment, CBT-I reduced PTSD symptoms in the context of high coping motives (B= -26.52, SE=8.41, p=.003), but not low (B= -0.55, SE=7.62, p=.94) coping motives.

Conclusion:  CBT-I appears to be especially effective in reducing PTSD symptoms among Veterans who frequently drink to cope with anxiety and depression. Future studies are needed to determine if and how we might extend this short-term benefit. Reducing PTSD symptoms in veterans with AUD could improve individuals’ well-being, in addition to alleviating financial strain and public health concerns regarding effective treatment for this population.