Objective: Personality has been associated with clinical depression in general. However, few studies have investigated personality in relation to postpartum depression, and these studies reported inconclusive findings. Therefore, the present study focused on neuroticism and introversion in the prediction of postpartum depression.
Method: In a population-based prospective study, women were screened during mid-pregnancy on standard risk factors for depression. In a group of randomly selected women (n = 277), neuroticism and introversion were measured at 32 weeks gestation. Clinical depression (Research Diagnostic Criteria) and depressive symptoms (Edinburgh Postnatal Depression Scale) were measured at 32 weeks gestation and at 3, 6, and 12 months postpartum.
Results: High neuroticism was associated with an increased risk of clinical depression and depressive symptoms during the postpartum period. The combination of high neuroticism and high introversion was the only independent predictor of clinical depression across the first year postpartum (odds ratios: 3.08, 4.64, and 6.83 at 3, 6, and 12 months postpartum, respectively, p < .05-.01), even when controlling for clinical depression during pregnancy. History of depression was the only other independent predictor during the early but not during the late postpartum. Inclusion of personality not only significantly improved the detection of women at increased depression risk but also the identification of women with an extremely low depression risk.
Conclusions: Personality may be an important and stable determinant of postpartum depression. The combination of high neuroticism and high introversion considerably improved the risk estimates for clinical depression across the first year postpartum.