Personality traits in the differentiation of major depressive disorder and bipolar disorder during a depressive episode

The aim of this study was to determine the differences in personality traits between individuals with Major Depressive Disorder (MDD) and Bipolar Disorder (BD) during a depressive episode, when it can be hard to differentiate them. Data on personality traits (NEO-FFI), mental disorders (Mini International Neuropsychiatric Interview Plus) and socioeconomic variables were collected from 245 respondents who were in a depressive episode. Individuals with MDD (183) and BD (62) diagnosis were compared concerning personality traits, clinical aspects and socioeconomic variables through bivariate analyses (chi-square and ANOVA) and multivariate analysis (logistic regression). There were no differences in the prevalence of the disorders between socioeconomic and clinical variables. As for the personality traits, only the difference in Agreeableness was statistically significant. Considering the control of suicide risk, gender and anxiety comorbidity in the multivariate analysis, the only variable that remained associated was Agreeableness, with an increase in MDD cases. The brief version of the NEO inventories (NEO-FFI) does not allow for the analysis of personality facets. During a depressive episode, high levels of Agreeableness can indicate that MDD is a more likely diagnosis than BD.