Dynamics of risk: Recent changes in psychological inflexibility precede subsequent changes in returning US veterans' posttraumatic stress

Objectives As a malleable risk-factor, psychological inflexibility is implicated in the development and maintenance of posttraumatic stress symptoms (PTS). Unfortunately, limited research has addressed whether changes in psychological inflexibility are antecedent to changes in PTS severity over time, or whether such changes are mutually dependent. Methods Utilizing bivariate latent difference score modeling, this longitudinal study sequenced intraindividual changes in psychological inflexibility and PTS severity within a sample of 305 returning US veterans. Veterans' self-reported psychological inflexibility and PTS severity were assessed quarterly over 1 year. Results Results indicated that early reductions in psychological inflexibility potentiated later declines in veterans' PTS severity, accounting for veterans' prior levels of psychological inflexibility and PTS severity. Conclusions These findings underscore the unique role of changes in psychological inflexibility as an important mechanism of change in PTS severity and provide empirical support for an antecedent model of the role of psychological inflexibility in PTS recovery.