When and Under What Circumstances Does Neuroticism Change in the Unified Protocol?

Neuroticism is associated with a range of psychopathology and targeted by the Unified Protocol (UP). Although the UP has led to reductions in neuroticism, it is unclear when these reductions occur and if greater reductions occur in response to a personalized sequence of skills. Method: Seventy adult participants (M_age = 33.74, 67% female, 74% White) with an emotional disorder were randomized to (a) receive UP modules in an order that capitalized on their strengths, compensated for their deficits, or a standard order and (b) receive 6 or 12 sessions of treatment. We conducted piecewise hierarchical linear regression models to test if specific sequencing or duration conditions led to greater reductions in neuroticism. Results: Changes in neuroticism did not significantly differ between the treatment duration conditions over the first six sessions, however, those in the full treatment condition exhibited significantly greater reductions in neuroticism from weeks 7-12. When controlling for depressive and anxiety symptoms, there were no significant changes in neuroticism in the first six sessions. Those in the full treatment condition demonstrated significant reductions in neuroticism from sessions 7-12. Conclusion: Brief treatment may exhibit state-level changes in neuroticism, but a more extensive course may be needed for lasting trait change.