Mania Triggered by Sleep Loss: Implications for Postpartum Psychosis

Background and Aims To examine whether a history of mood episodes triggered by sleep loss is associated with (1) postpartum psychosis (PP) and (2) more broadly-defined postpartum mood episodes that included postnatal depression (PND), in women with bipolar disorder (BD). Methods Participants were 622 parous women with a diagnosis of bipolar-I disorder recruited in the UK to the Bipolar Disorder Research Network. Diagnosis and perinatal episodes were assessed via interview and case note data. Women were also asked during the interview whether episodes of mania and/or depression were triggered by sleep loss. We compared the rates of PP and PND within women who did and did not endorse sleep loss as a trigger of mood episodes. Results Women who reported that their episodes of mania were usually triggered by sleep loss were twice as likely to have experienced an episode of PP (OR = 2.00, 95% CI = 1.20–3.36) than women who did not report this. This effect remained significant when controlling for clinical and demographic factors. We found no significant associations between depression triggered by sleep loss and PP. Analyses in which we defined postpartum episodes at a broader level to include both PP and PND were not significant. Conclusions In pregnant women with BD, a history of mania following sleep loss could be a potential marker of vulnerability to severe postpartum episodes. Further study in prospective samples is required in order to confirm these findings, which may have important implications for understanding the aetiology of PP and of mood disorders more generally.