- Michael Bauer: Department of Psychiatry and Psychotherapy, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany. michael.bauer@uniklinikum-dresden.de
BACKGROUND: Psychosocial interventions may teach patients with bipolar disorder to successfully detect warning signs of relapse. These interventions often include ongoing self-monitoring of sleep. We previously reported that a change in sleep duration (sleep plus bedrest) of >3 h may indicate that a mood change is imminent. This analysis further investigated whether sleep duration, sleep onset or sleep offset was the most useful sleep/wake parameter to monitor for an oncoming mood change.
METHODS: 101 adult outpatients receiving treatment as usual recorded mood, sleep and medications every day on a home computer for a mean of 265+/-103 days. A daily time series of mood, sleep duration (sleep plus bedrest), sleep onset and sleep offset was constructed for each patient. After applying an ARIMA (0,1,1) filter, a cross correlation function was used to analyze the temporal relationship between the residuals for lags of +/-7 days.
RESULTS: Less frequent significant correlations were found between a change in either sleep onset or sleep offset and mood, than between sleep duration and mood. Patients with a significant correlation between sleep duration and mood included 86% of those with a significant correlation between sleep onset or sleep offset and mood. Mean sleep duration when euthymic was long (> or =8 h in 89% of patients, > or =9 h in 51% of patients).
LIMITATIONS: Self-reported data, naturalistic study, and computer access required.
CONCLUSIONS: Self-monitoring of sleep duration is recommended for patients with bipolar disorder. Better understanding of the long sleep duration of euthymic patients is required.