Sleep Loss as a Trigger of Mood Episodes in Bipolar Disorder: Individual Differences Based on Diagnostic Subtype and Gender

Background: Sleep loss may trigger mood episodes in people with bipolar disorder (BD) but individual differences could influence vulnerability to this trigger.

Aims: To determine whether bipolar subtype (BD-I or BD-II) and gender were associated with vulnerability to the sleep loss trigger.

Method: During a semi-structured interview, 3140 individuals (68% female) with BD (66% BD-I) reported whether sleep loss had triggered episodes of high or low mood. DSM-IV diagnosis of bipolar subtype was derived from case note and interview data.

Results: Sleep loss triggering episodes of high mood was associated with female gender (OR = 1.43, 95% CI 1.17-1.75, P <.001) and BD-I subtype (OR = 2.81, 95% CI 2.26-3.50, P <.001). Analyses on sleep loss triggering low mood were not significant following adjustment for confounders.

Conclusions: Gender and bipolar subtype may increase vulnerability to high mood following sleep deprivation. This should be considered in situations where patients encounter sleep disruption, such as shift-work and international travel.