Saturday, October 07, 2006
Bipolar Disorder and Sleep
Sleep disturbance is a well-recognized feature of acute psychiatric illness, and is included in the diagnostic criteria of many of the affective and anxiety disorders. Recent research has found that disrupted sleep and sleep complaints are common in patients with affective disorder even between mood episodes. Treatment of disrupted sleep and the maintenance of a regular sleep/wake cycle are important components of the prophylaxis of mood episodes in bipolar disorder.
Sleep disturbance is a cardinal feature of bipolar disorder. During acute mania, patients exhibit markedly reduced sleep time and report a reduced need for sleep. Even when euthymic, sleep disturbance is common. In a recent study, 55% of euthymic bipolar patients had chronic insomnia (Harvey et al 2005). Children with bipolar disorder (who often display ultradian rapid cycling rather than distinct mood episodes) exhibit reduced sleep efficiency and frequent nocturnal awakenings (Mehl et al 2006).
JW, a single 25 year-old female with bipolar type I disorder, had been relatively stable for the last three years on a regime of lithium 600 mg twice daily and Ambien (zolpidem) 10 mg at bedtime. She had not had a distinct mood episode since her last episode of bipolar mania three years ago. She obtained 7 to 8 hours of sleep at night, and was satisfied with her job as a respiratory therapist working for a durable medical equipment (DME) company.
Four weeks ago, the DME company went out of business, and JW took a job as a sleep technician working for a growing sleep disorders center. This exciting job involved working 8 pm to 6 am Tuesday through Friday. JW was only able to sleep 5-6 hours after her shift, even with the aid of Ambien. She slept about seven hours on nights she was not working.
Three days ago, on a Saturday morning, JW felt unusually energized as she was finishing her shift. She drove home and spent the next sixteen hours cleaning her house from top to bottom. JW then slept for an hour and went to a dance club. She left the dance club when it closed at 3 am and returned to her house, where she slept for two hours. She exercised extensively on Sunday and showed up at the sleep center Sunday night. She told her co-workers she was there because she was now the owner of the sleep center and she wanted to make sure they were doing their jobs right. She was talking rapidly and pacing. JW became agitated when the the other sleep technicians refused to take orders from her. The medical director was called. He, with great difficulty, was able to convince her to go to the ER. The medical director and a technician drove her to the ER, where treatment was begun for a bipolar manic episode.
Comment: JW developed a manic episode with symptoms of grandiosity, decreased need for sleep, rapid speech, and increased goal-directed activity. A change in sleep habits can precipitate a bipolar mood episode. Night work and shift work have a destabilizing influence on bipolar disorder.
Bipolar disorder is treated with mood stabilizing agents such as sodium valproate, carbamazepine, or lithium. Addition of an antidepressant may be necessary to control bipolar depression. The maintenance a stable sleep/wake cycle, as well as regularization of the circadian rhythm, are key components of a relatively new psychotherapy for bipolar disorder, Interpersonal and Social Rhythm Therapy (IP-SRT). IP-SRT is most effective for mood episode prophylaxis in the maintenance phase of bipolar, and in individuals without significant medical comorbidity or anxiety (Frank et al 2005).
The above is from a chapter I am writing for Medlink Neurol0gy entitled "Sleep disorders associated with mental disorders". It is copyrighted by Medlink Neurology.