Do patients' cognitive therapy skills predict personality change during treatment of depression?

Background: Psychological interventions can change personality, including increasing positive temperament (extraversion) and decreasing negative temperament (neuroticism), but why these changes occur is unclear. The current study tested the extent to which patients' acquisition and use of skills taught in cognitive therapy (CT) correlated with changes in positive and negative temperament during treatment of depression. Method: Outpatients (N = 351) with recurrent major depressive disorder (MDD) were enrolled in a 12-week CT protocol. Temperament (early and late in CT), patient skills (mid and late in CT), and depressive symptoms (early, mid, and late in CT) were measured repeatedly. Results: Patients with greater acquisition and use of CT skills showed significantly larger increases in positive temperament and larger decreases in negative temperament in path analyses. Effect sizes were small, median standardized vertical bar beta vertical bar = 0.13. Models controlled depressive symptom levels and changes. Conclusions: Skills taught in CT for recurrent depression correlate with personality change during this efficacious treatment. The absence of measures of CT skills at baseline and personality mid-CT allows several interpretations of the current findings. Future research is needed to clarify whether patients' use of CT skills facilitates adaptive changes in personality during CT.