Perinatal sleep disruption and postpartum psychosis in bipolar disorder: Findings from the UK BDRN Pregnancy Study

Background
Women with bipolar disorder (BD) are at high risk of postpartum psychosis (PP). The factors that increase risk of PP among women with BD are not fully understood. Here, we examine whether sleep disruption in the perinatal period (poor sleep quality in late pregnancy and sleep deprivation related to childbirth) is associated with PP in a longitudinal study of pregnant women with BD.

Methods
Participants were 76 pregnant women with lifetime DSM-5 bipolar I disorder or schizoaffective-BD, followed from week 12 of pregnancy to 12 weeks postpartum. Demographics and lifetime psychopathology were assessed at baseline via semi-structured interview (Schedules for Clinical Assessment in Neuropsychiatry). Psychopathology and sleep disruption within the current perinatal period were assessed in the third trimester and at 12 weeks postpartum. Data were supplemented by clinician questionnaires and case-note review.

Results
After controlling for prophylactic use of mood stabilising medication, the loss of at least one complete night of sleep across labour/delivery was associated with five times the odds of experiencing PP compared to no or less than one night of sleep loss across labour/delivery (OR 5.19, 95 % CI 1.45–18.54; p = 0.011). Sleep quality in late pregnancy was not associated with PP, and perinatal sleep disruption was not associated with postpartum depression.

Limitations
Lack of objective measures of sleep factors.

Conclusions
In the context of other aetiological factors, severe sleep loss associated with childbirth/the immediate postpartum may act as a final trigger of PP. These findings could have important clinical implications for risk prediction and prevention of PP.