Distress tolerance as a mechanism of PTSD symptom change: Evidence for mediation in a treatment-seeking sample.

Low distress tolerance, the perceived or actual inability to tolerate negative emotional states, is a transdiagnostic risk marker associated with greater PTSD symptoms and poorer treatment outcomes. However, the role of distress tolerance in PTSD symptom trajectories has not yet been explored. This study examined the mediating role of distress tolerance in PTSD symptom change among outpatients participating in a trial of computerized interventions for anxiety-related and mood-related risk factors. It was hypothesized that pre- to post-intervention change in distress tolerance would predict PTSD symptoms at three- and six-month follow-up, and mediate the effect of condition on PTSD symptoms above and beyond the effects of a competing mediator, anxiety sensitivity. Although condition differences in distress tolerance change were non-significant, distress tolerance change predicted month-three PTSD symptoms and mediated the direct effect of condition on month-three PTSD symptoms. After accounting for the direct effect of condition on month-six PTSD symptoms, distress tolerance change did not predict month-six PTSD symptoms. Findings suggest distress tolerance does play a longitudinal role in PTSD symptom change, and distress tolerance interventions may benefit certain samples who may otherwise not be able to immediately access, or remain in PTSD treatments.