Reciprocal relationships between posttraumatic stress disorder symptoms and positive and negative affect in evidence-based treatments for posttraumatic stress disorder.

Objective: Posttraumatic stress disorder (PTSD) is associated with elevated negative affect (NA; e.g., Badour et al., 2017) and diminished positive affect (PA; Nawijn et al., 2015). PTSD treatments reduce NA (e.g., Jerud et al., 2014), but changes in PA and relationships between changes in affect and PTSD symptoms remain unclear.
Method: This study examined changes in PA and NA in adults (N = 130) with PTSD receiving prolonged exposure (PE) or PE plus sertraline as part of a randomized controlled trial (NCT01600456). Participants completed measures of affect (PANAS; Watson et al., 1988) and PTSD symptoms at 10 weekly treatment sessions. Cross-lagged dynamic structural equation models examined associations between session-to-session fluctuations in affect and PTSD.
Results: PA increased moderately (d = 0.51) and NA decreased strongly (d = 0.78) across treatment sessions. Within-person fluctuations in PA and NA were generally reciprocal, PAt → NAt+1: effect size (ES) = -0.09, 95% CI [-0.15, -0.02]; NAt → PAt+1: ES = -0.20, 95% CI [-0.28, -0.13]. However, fluctuations in PTSD more strongly predicted next session NA (PTSDt → NAt+1: ES = 0.50, 95% CI [0.38, 0.60]) and PA (PTSDt → PAt+1: ES = -0.26, 95% CI [-0.34, -0.17]) than the reverse. PE augmentation with a selective serotonin reuptake inhibitor did not moderate temporal associations.
Conclusions: Prolonged exposure produced substantial improvements in PA and NA. General affective changes may be more a consequence than a driver of PTSD improvement during PE, with improvements in NA and PA potentially linked to the extinction of negative emotional responses to trauma cues and increased engagement with rewarding activities, respectively. (PsycInfo Database Record (c) 2024 APA, all rights reserved).