Ecological Momentary Assessment of Positive and Negative Affect in Posttraumatic Stress Disorder

Although posttraumatic stress disorder (PTSD) is characterized by negative affect (NA), much less is known about daily fluctuations in positive affect (PA) and its association with NA in PTSD. In the present study, participants with sexual assault-related PTSD (n = 19), a sexual assault experience without PTSD (n = 20), and healthy controls (n = 21) completed an ecological momentary assessment (EMA) where they reported positive and negative affect in the morning, afternoon, and evening for one week. The results showed that those with PTSD reported less daily positive affect independent of momentary negative affect and more daily negative affect independent of momentary positive affect than controls. Examination of directional affective valence (positive affect minus negative affect) also indicated overall more negative affect among those with PTSD compared to controls. However, those who experienced sexual assault without PTSD did not differ from controls in daily positive affect, daily negative affect, or directional affective valence. Although there was no evidence of differences in daily levels of positive and negative affect as a function of time of day among those with PTSD, decreased positive affect was observed in the evening among those who experienced sexual assault without PTSD. These findings suggest that PTSD is characterized by independent momentary increases in negative affect as well as independent momentary decreases in positive affect, both of which should be addressed during the course of evidence-based treatment.