Mania triggered by sleep loss and risk of postpartum psychosis in women with bipolar disorder

Background: Women with bipolar disorder are at high risk of affective psychoses following childbirth (i.e. "postpartum psychosis", PP) and there is a need to identify which factors underlie this increased risk. Vulnerability to mood dysregulation following sleep loss may influence risk of PP, as childbirth is typified by sleep disruption. We investigated whether a history of mood episodes triggered by sleep loss was associated with PP in women with bipolar disorder (BD). Methods: Participants were 870 parous women with BD recruited to the Bipolar Disorder Research Network. Lifetime diagnoses of BD and perinatal episodes were identified via interview and case notes. Information on whether mood episodes had been triggered by sleep loss was derived at interview. Rates of PP were compared between women who did and did not report mood episodes following sleep loss. Results: Women who reported sleep loss triggering episodes of mania were twice as likely to have experienced an episode of PP (OR = 2.09, 95% CI = 1.47-2.97, p < 0.001) compared to women who did not report this. There was no significant association between depression triggered by sleep loss and PP (p = 0.526). Limitations: Data were cross-sectional therefore may be subject to recall bias. We also did not have objective data on sleep disruption that had occurred during the postpartum period or prior to mood episodes. Conclusions: In clinical practice, a history of mania following sleep loss could be a marker of increased vulnerability to PP, and should be discussed with BD women who are pregnant or planning to conceive.