Identifying features of bipolarity in patients with first-episode postpartum depression: Findings from the international BRIDGE study

Objectives: The aims of this study were to assess rates of bipolar spectrum disorders in women experiencing their first episode of postpartum depression, and to find out features indicative of bipolarity in these patients. Methods: As part of the international BRIDGE study designed to detect hypo/mania in patients with a major depressive episode, 52 (5.85%) were found to experience a first episode of postpartum (FEPP) depression, whereas 833 (94.13%) had a first episode of nonpostpartum (FENPP) depression. Hypo/mania was assessed using varying definitions of bipolarity, and the two groups compared on sociodemographic, family history and clinical characteristics. Results: Compared to FENPP depressive patients, women with FEPP depression had higher rates of bipolar disorders, with more hypo/mania in first degree relatives. Psychotic symptoms, atypical features, mixed depression, younger age at onset, high number of prior episodes, episodes of short duration, switches on antidepressants, seasonality of mood episodes as well as mood episodes with free intervals were found to be more frequent in FEPP depressives. Limitations: The following are the limitations of this study: centres not randomly selected, recall bias, cross-sectional design, and limited training of participating psychiatrists. Conclusions: This study confirms, in women experiencing a first depressive episode, high rates (15 to 50%) of bipolar disorders during the postpartum period and is the first to systematically assess and demonstrate the higher prevalence of identifying features of bipolarity in FEPP versus FENPP depression. Early recognition of bipolarity in these patients may help prevent the harmful consequences of this illness.