Differential Associations Between Sleep Domains and Response to Prolonged Exposure Therapy

Prolonged Exposure (PE) is an effective evidence-based psychotherapy for posttraumatic stress disorder (PTSD); however, a small subset of veterans fails to achieve meaningful symptom reduction from PE. Given sleep's role in memory consolidation, poor sleep quality may adversely affect fear extinction learning central to PE. Existing research on sleep and PE response often relies on single-item or global measures that miss nuanced sleep processes, assesses sleep as static (e.g., at baseline) rather than as a dynamic process, or focuses on concurrent rather than prospective associations. This study used a multidimensional measure of sleep quality to evaluate whether changes across several domains of sleep concurrently and prospectively predicted reduced PTSD symptoms. Sleep quality was assessed pre- and post-treatment and PTSD symptoms were measured pre- and post-treatment and at 3- and 6-month follow-ups. Changes in sleep domains were analyzed as predictors of concurrent and prospective PTSD symptoms. Improvements in overall sleep quality, subjective sleep quality, and daytime dysfunction were associated with improvements in PTSD symptom severity from pre- to post-treatment. Greater improvements in overall sleep quality and daytime dysfunction predicted lower PTSD severity at follow-up; however, greater reductions in daytime dysfunction predicted symptom increases across follow-up. Our findings highlight the importance of overall sleep quality in PE response and suggest that daytime dysfunction due to sleep problems may contribute to diminished long-term outcomes. Targeting these aspects of sleep may enhance treatment efficacy.