Objectives: Research on unipolar depression has found that life events that are congruent with an individual's personality style increase vulnerability to depression (event congruency hypothesis). We tested whether the interaction of personality style and congruent life events predicted prospective increases in depressive and hypomanic symptoms among bipolar spectrum individuals over a 4-month follow-up.
Methods: We followed 106 bipolar II or cyclothymic individuals prospectively for 4 months. Participants completed three measures of personality style at time 1 and a life event scale and semi-structured life events and diagnostic interviews at follow-up. Life events were coded as congruent or non-congruent with the personality styles.
Results: A personality style characterized by self-criticism and performance evaluation interacted with congruent negative and positive events, respectively, to predict increases in depressive and hypomanic symptoms, respectively, over the 4 months. In contrast, an attachment-oriented personality style buffered against depression following congruent negative events.
Conclusion: Consistent with the event congruency hypothesis, a personality style focused on performance, high self-standards, and self-criticism may increase vulnerability to both depressive and hypomanic symptoms when bipolar individuals confront life events congruent with this style. In contrast, a personality style concerned with attachment to others may buffer against depression when bipolar individuals face congruent negative events.