Dimensional personality traits and treatment outcome in patients with major depressive disorder

Background tudy investigated the association between dimensional personality traits from the Five-Factor Model (FFM) and treatment outcome in patients with Major Depressive Disorder (MDD). s ndred forty-nine outpatients with MDD participated in a randomised double-blind longitudinal study for 6 months. Patients received a combination of medication and psychotherapy; they were randomised to medication condition (tianeptine or fluoxetine), and non-randomly assigned to psychotherapy condition (supportive, cognitive-behavioural, or psychodynamic). The Montgomery Asberg Depression Rating Scale was used to assess depression severity. The Système de Description en Cinq Dimensions was used to assess the personality domains of the FFM. s comparisons revealed that patients who responded to both medication and psychotherapy had lower Neuroticism (t = 4.22, p < .01), and higher Extraversion (t = 4.01, p < .01) and Openness to Experience scores (t = 3.57, p < .01) compared to non-responders. Regression analyses, which controlled for shared variance among the five personality domains, indicated that Neuroticism (χ2 = 4.06, p = .04) and Conscientiousness (χ2 = 8.98, p < .01) were significantly and uniquely associated with response. The two-way interactions between Neuroticism × Extraversion (χ2 = 4.49, p = .03) and Extraversion × Conscientiousness (χ2 = 5.91, p = .01) were also associated with response. These results were mostly replicated across the treatment-completer and intent-to-treat samples. sions ional personality traits predict response for individuals with MDD. tions tudy did not examine facet-level traits, patient pre-morbid personality and functioning, and additional patient characteristics. Results may not be generalizable to severely depressed or treatment refractory patients.