Insomnia and other sleep problems frequently afflict people with bipolar disorder, even when they're taking medications that quell their extreme emotional highs and lows, a new study suggests. Fear and anxiety that sleep loss will trigger bouts of mania or depression—the cardinal features of bipolar disorder—wreak havoc on slumber among these individuals, say psychologist Allison G. Harvey of the University of California, Berkeley and her colleagues.
The researchers compared interview and questionnaire responses of 20 adults with bipolar disorder, 20 people with insomnia, and 20 good sleepers. All 60 volunteers also kept sleep diaries for 8 consecutive days. During that time, small devices worn on the wrist monitored each person's physical motion at night.