A prospective examination of the role of psychological (in)flexibility in posttraumatic stress: A cross-lagged panel design.

Functional contextualist models of psychopathology suggest that psychological inflexibility and psychological flexibility are of central importance for understanding the development and maintenance of posttraumatic stress (PTS) symptomatology. To our knowledge, these two constructs and their domain-specific factors (e.g., cognitive fusion, experiential avoidance) have not been assessed in their entirety and examined in relation to PTS symptoms using a longitudinal study design. As such, the primary aim of the present study was to use cross-lagged panel analysis, an analytic approach that allows stronger causal inferences to be made regarding the nature of temporal relations among study variables, to determine the directional relations among PTS symptoms and psychological flexibility and inflexibility over an eight-month time period. Trauma-exposed adults (N = 810), recruited online via Amazon's Mechanical Turk (MTurk), completed a battery of self-report measures via a secure online platform at three time points, spanning eight months. Results suggest that the relationship between psychological inflexibility and PTS symptoms is bidirectional and mutually reinforcing. In contrast, significant prospective relations were not observed between psychological flexibility and PTS symptoms. Results of a follow-up exploratory path analysis showed that cognitive fusion was the only psychological inflexibility subfactor that partially mediated the relationship between PTS symptoms from baseline to the eight-month follow-up assessment. Taken together, these results suggest that psychological inflexibility, and primarily the domain of cognitive fusion, maintains PTS symptoms following trauma exposure. As such, it may important to integrate cognitive defusion techniques into evidence-based treatments for Posttraumatic Stress Disorder (PTSD).