Background: The modern practice of using artificial light to extend waking activities into the nighttime hours might be expected to precipitate or exacerbate bipolar illness, because it has been shown that modifying the timing and duration of sleep can induce mania in susceptible individuals. With this possibility in mind, we treated a patient with rapidly cycling bipolar illness by creating an environment that was likely to increase and to stabilize the number of hours that he slept each night.
Methods: We asked the patient to remain at bed rest in the dark for 14 hours each night (later this was gradually reduced to 10 hours). Over a period of several years, his clinical state was assessed with twice-daily self-ratings, once-weekly observer ratings, and continuous wrist motor activity recordings. Times of sleeping and waking were recorded with sleep logs, polygraphic recordings, and computer-based event recordings.
Results: The patient cycled rapidly between depression and mania and experienced marked fluctuations in the timing and duration of sleep when he slept according to his usual routine, but his sleep and mood stabilized when he adhered to a regimen of long nightly periods of enforced bed rest in the dark.
Conclusions: Fostering sleep and stabilizing its timing by scheduling regular nightly periods of enforced bed rest in the dark may help to prevent mania and rapid cycling in bipolar patients.