Investigating the dynamic coevolution of coping self-efficacy and posttraumatic stress symptoms after hurricane florence: An empirical test of self-regulation shift theory.

Self-regulation shift theory (SRST) provides a nonlinear dynamical systems-based theory of posttraumatic psychological adaptation. SRST has two central tenets: (1) coping self-efficacy and posttraumatic stress symptoms (PTSS) dynamically coevolve, such that changes in one correspond with changes in the other, and (2) that this coevolution produces critical transitions in psychological state for a subset of trauma survivors, including a self-determination violation (a decrease in coping self-efficacy paired with a rapid increase in PTSS) and/or a self-determination resurgence (an increase in coping self-efficacy paired with a rapid decrease in PTSS). Though existing evidence generally supports these tenets, SRST has yet to be robustly evaluated using nonlinear dynamical systems-based analytic approaches. This study evaluated these tenets using six weeks of ecological momentary assessment data from 81 hurricane survivors reporting continued hurricane-related stress 5-8.5 months after Hurricane Florence. Coping self-efficacy and PTSS velocities were estimated using functional data analysis, and generalized additive modelling was then used to evaluate dynamic coevolution. Results suggested that coping self-efficacy and PTSS velocities coevolved for 91-96% of participants. Inspection of gradient plots suggested approximately 6% of survivors exhibited nonlinear transitions consistent with SRST's self-determination violation and an additional 6% exhibited nonlinear transitions consistent with SRST's self-determination resurgence. Results provide preliminary support for SRST's tenets and suggest that interventions targeting either PTSS or coping self-efficacy may generate cascading benefits across the psychological system. It also adds to the growing body of literature suggesting nonlinear dynamical systems-based approaches can offer considerable insight into posttraumatic psychological processes.