(PS2-B33) Ruminative Processing and Avoidance During Prolonged Exposure with and Without Sertraline

Posttraumatic stress disorder (PTSD) is often seen in conjunction with major depressive disorder (MDD), with co-occurrence rates reported to be as high as 50% to 80% (Rytwinski et al., 2013; Spinhoven et al., 2014). The common developmental pathways underlying the co-occurrence remain unclear. Rumination may be a shared cognitive process that underlies the development of both PTSD and depression (Roley et al., 2015; Schumm et al., 2022), potentially serving as a cognitive avoidance strategy (Ehlers & Steil, 1995; Michael et al., 2007). However, the role of rumination as a potential exacerbating factor, either during or post-treatment, warrants further study, particularly as it relates to PTSD, depression, and avoidance.

Individuals with PTSD (N = 149) were part of a doubly randomized control trial, receiving either PE or PE + sertraline for 10 weeks and followed through 9 months. Preliminary completer analyses revealed that ruminative processes significantly decreased from pre to post-treatment (Cohen’s d = 0.77, p = 0.02). Furthermore, higher levels of baseline rumination were associated with higher levels of depression symptoms at post-treatment (p < 0.001), 3-month follow-up (p = 0.03), and 9-month follow-up (p < 0.001). Rumination was also associated with higher overall PTSD severity at both post-treatment (p = 0.017) and 9-month follow-up (p < 0.001). Higher baseline rumination was associated with higher PTSD avoidance symptoms at post-treatment (r2 = 0.042, p = 0.031) and 9-month follow-up (r2 = 0.099, p < 0.001).

Further analyses reporting the intent-to-treat sample and relapse of depression symptoms will also be examined. In general, rumination improved over the course of PE and PE + sertraline treatment. Higher baseline rumination was associated with slightly higher PTSD and depression at post-treatment and may represent a dysfunctional avoidance cognition style that may confer future vulnerability to the persistence or re-emergence of symptoms.