6 - (IOP 29) The Role and Impact of Insomnia Among Veterans Receiving Treatment for PTSD and AUD

Insomnia, posttraumatic stress disorder (PTSD), and alcohol use disorder (AUD) commonly overlap among veterans and are associated with poor psychosocial and treatment outcomes. Integrated approaches to treating comorbid PTSD and AUD are effective. However, the impact of insomnia on these treatments and vice versa are poorly understood. This study examined the impact of pre-treatment insomnia on post-treatment PTSD and AUD outcomes. Conversely, this study examines the extent to which integrated treatments for PTSD and AUD address insomnia. Participants were veterans diagnosed with both PTSD and AUD (N = 100) who received prolonged exposure therapy (PE) and either placebo or topiramate (an anticonvulsant medication with off-label use for alcohol craving) as part of a randomized controlled trial. Participants completed self-report and interview measures of insomnia severity (ISI), PTSD severity (PCL-5), and alcohol consumption (TLFB) at pre- and post-treatment. Preliminary analyses revealed that insomnia severity was moderately correlated with PTSD severity (r = 0.49) but not number of binge-drinking days (r = 0.09) at baseline for all participants. Linear regressions revealed that baseline insomnia severity did not predict post-treatment PTSD severity (b = 0.19, SE = 0.44, p = 0.67) or the number of binge-drinking days at post-treatment (b = 0.03, SE = 0.47, p = 0.95) after controlling for pre-treatment symptoms. Finally, meeting the clinical threshold for insomnia at baseline (n = 76; 76%) was associated with a significantly higher chance of meeting the clinical threshold for insomnia at post-treatment (n = 35; 53.8%; OR = 29.8, 95% CI [6.48, 289.16]). Further analyses will be conducted to examine whether there are differences between the treatment groups (PE + topiramate vs. PE + placebo). Findings suggest that patients with comorbid PTSD and AUD may benefit from PE with and without topiramate even when insomnia is present. However, these treatments alone may not effectively address insomnia, which may require its own targeted intervention. This study was conducted in mostly male (84%) veterans, which may limit generalizability to other samples. Future studies are needed to identify mechanisms underlying insomnia symptom improvement in different populations and to enhance the development of integrated treatments that can address multiple comorbidities.