Background: Increasingly, the Five Factor Model (FFM) of personality is being used to assess personality characteristics of patients with Axis I disorders. Recent study indicates that patients with the seasonal subtype of major depression (SAD) may differ meaningfully from other depressed patients. In the present study, we further examined this finding, with attention to the stability of personality characteristics across treatment.
Methods: We used the NEO-FFM to assess the personality characteristics of two samples of depressed outpatients: patients with SAD and patients with bipolar disorder. Assessment was repeated in the SAD patients after light therapy.
Results: Consistent with previous research, we found elevated scores on the Openness domain in the SAD patients. SAD patients also scored significantly lower on Neuroticism and significantly higher on the Conscientiousness and Extroversion domains than patients with bipolar disorder. Scores on the Openness domain remained elevated after treatment of SAD; this occurred in the context of significant decreases in Neuroticism and increases in Extroversion scores.
Limitations: These results were obtained in a relatively small-sample study. Although our sample of bipolar patients were taking mood stabilizers, it is unlikely that medication effects could explain our results.
Conclusions: Our findings are consistent with those reported by Bagby et al. (Major depression and the five-factor model of personality. J. Pers. Disord. 1995;9:224-234) and suggests that Neuroticism and Extroversion are the FFM domains most responsive to treatment for depression. Our results also suggest that elevations on the Openness domain do not change with treatment and may be an enduring characteristic of patients with SAD.