Personality traits are risk and protective factors in affective disorders. However, few studies have investigated the role of narrow personality facets, with existing research yielding contradictory results. Previous research has mostly focused on simple correlations. Several studies have performed separate multiple regressions within each trait, and have used nonstandard measures of personality, making it difficult to determine how individual facets make unique contributions.
This study performed secondary analysis of the NewMood data set (collected 2004-2009), comprising 264 participants from Greater Manchester. Participants provided self-reports of all NEO-PI-R personality facets, and semi-structured questionnaires of clinical depression and anxiety. All personality facets were entered into multiple regressions to explain variance in depression and anxiety.
Variance in both anxiety and depression were explained by a small number of personality facets, namely facet depression (referring to demotivation), facets positive emotion and assertiveness in extroversion, and facet competence in conscientiousness.
This study relies on cross-sectional data and cannot determine causation. This study uses a mostly female sample, and the results were not stratified by sex due to the small sample.
Previous studies suggest that broad trait neuroticism positively associates with affective disorders; this study adds that the effect of neuroticism is limited to facet depression (related to demotivation). Contrary to previous studies, no facet of agreeableness or openness explained variance in affective disorders, and facet assertiveness positively associated with affective disorder scores. These findings may help to improve treatment matching and explain the mechanisms through which affective disorders develop.