(PS12-A16) Response to Negative Affect Treatment and Positive Affect Treatment Is Moderated by Extraversion and Neuroticism Personality Traits

Neuroticism is characterized by high negative affect and low positive affect whereas extraversion is characterized by low negative affect and high positive affect. Neuroticism has been identified as a predictor of depression and anxiety symptom onset, whereas extraversion has been identified as a protective factor against the onset of these symptoms. Additionally, neuroticism predicts poor response to cognitive behavioral therapy (CBT), whereas extraversion is associated with greater symptom improvement in CBT. Recently, novel positive-focused treatments have been shown to significantly reduce internalizing symptoms. However, it is unclear whether personality traits such as neuroticism and extraversion similarly predict outcomes in such positive-focused treatments. 

Thus our study examines whether neuroticism and extraversion moderate treatment response in a randomized controlled trial comparing a novel positive affect treatment (PAT; Craske et al 2019) and a negative affect treatment (NAT, similar to standard CBT). We hypothesized that PAT would be most effective for those with low extraversion compared to NAT, given that PAT is designed to increase deficits in positive affect. High extraversion predicts higher treatment response in general, so we hypothesized that both treatments would be equally effective for those with high extraversion. We hypothesized that individuals with low neuroticism would perform equally well in both conditions, but predicted that PAT would be most effective for those with high neuroticism compared to NAT, because of its emphasis on increasing low positive affect. Participants (N = 85) at the University of California, Los Angeles and Southern Methodist University with depression and anxiety were randomized to receive 15 weeks of PAT or NAT. The self-report Positive and Negative Affect Schedule (PANAS) and the Depression, Anxiety and Stress Scale (DASS-21) were completed at baseline, before each therapy session, and at post-treatment. The Eysenck Personality Questionnaire for Neuroticism (EPQN) and the Big Five Aspects Scale for Extraversion (BFAS) were completed at baseline.

Growth curve models were used to test whether baseline personality trait scores moderated the effect of treatment condition on DASS-total and PANAS scores over time. Extraversion significantly predicted change in positive affect over time such that those with high extraversion improved most rapidly in PAT (p = 0.011). Extraversion did not significantly predict DASS-total scores. Neuroticism significantly predicted change in positive affect over time such that those with low neuroticism improved most rapidly in PAT (p = 0.039). Neuroticism significantly predicted change in DASS-total scores over time (p = 0.032), such that higher neuroticism predicted more rapid symptom improvement, regardless of treatment condition. Findings offer support for neuroticism and extraversion as treatment moderators but are opposite from initial hypotheses, such that PAT appears to be most effective for individuals with high extraversion and low neuroticism. Future studies can expand this work by examining additional personality traits as moderators of treatment response to further facilitate treatment matching.