(PS10-52) Pre-treatment Post-traumatic Stress Disorder Symptoms Moderate Problem-solving Treatment Outcome for US Military Veterans Living with Gulf War Illness

The goals of this study were to examine associations of depression and post-traumatic stress disorder (PTSD) symptoms with health outcomes among military Veterans living with Gulf War Illness (GWI) and to understand how these symptoms affect problem-solving treatment (PST) outcome in this population. GWI is a chronic multisymptom illness characterized by chronic pain, fatigue, and neurocognitive difficulties that afflicts about 30% of military Veterans who deployed to the 1990-1991 Gulf War. PST is a cognitive behavioral intervention designed to help individuals improve problem-solving skills to address obstacles to personal and health-related goals. PST has been shown to be efficacious for many conditions, including reducing GWI-related problem-solving impairment and disability. This study was a randomized clinical trial of telephone-delivered PST for GWI with two arms: PST and health education (control). Data were collected at four timepoints: baseline, 4 weeks (mid-treatment), 12 weeks (end of treatment), and 6 months (post-treatment). 268 Veterans who met the Kansas criteria for GWI were randomized (n = 135 to PST arm). Outcomes included disability, measured by the World Health Organization Disability Assessment Schedule 2.0, and problem-solving impairment, measured by the Problem Solving Inventory. Multivariate linear regression (cross-sectional) and mixed model analyses (longitudinal) were used to examine associations of depression and PTSD symptoms with disability and problem-solving impairment at baseline and over time. All models covaried for household income as a proxy for socio-economic status. Greater depression and PTSD symptoms were both significantly associated with greater problem-solving impairment and greater disability at baseline (all p’s < 0.05). Baseline PTSD symptoms moderated the effect of PST on disability (p = 0.0102); Veterans with the highest baseline PTSD symptoms reported the greatest decreases in disability over time in PST. There was no evidence that depression symptoms moderated PST outcomes. Findings suggest mental health symptoms are an important consideration in the context of GWI care. Gulf War Veterans with comorbid PTSD symptoms not only can benefit from PST for GWI but may have the most to gain from this intervention. Future work should explore further the implications of comorbid mental health symptoms on GWI care.