Influences of the Big Five personality traits on the treatment response and longitudinal course of depression in patients with acute coronary syndrome: A randomised controlled trial.

BACKGROUND Influences of the Big Five personality traits on the treatment response and longitudinal course of depression in patients with acute coronary syndrome: A randomised controlled trial. METHODS This naturalistic observational study initially recruited 1152 ACS patients; 685 patients completed personality assessments at baseline, of whom 630 were followed-up one year later. Of the 294 patients with depression, 207 participated in a 24-week double blind trial of escitalopram or placebo. The remaining 87 patients who received medical treatment only and the 391 who had not depression were also followed in a one year naturalistic observational study. The Big five personality traits were assessed using the Big Five Inventory. The influences of personality on the Hamilton Depression Rating Scale score changes were analysed using a mixed-model repeated-measures analysis of covariance. RESULTS A Cluster analysis identified two personality types: resilient and vulnerable. The vulnerable personality type was characterized by lower extraversion, agreeableness, and conscientiousness - but higher neuroticism - than the resilient type. This personality type was independently associated with a poorer outcome of depression in ACS patients during the 24-week treatment period and the one year longitudinal follow-up period compared to the resilient personality type, irrespective of treatment allocation. LIMITATIONS Recruitment from a single institution may limit generalisability. Personality traits were investigated 12-weeks after ACS; thus, the responses may have been influenced by the prior receipt of escitalopram. CONCLUSIONS Personality types influences the treatment outcome and longitudinal course of depression in ACS patients independent of antidepressant treatment.