When their daily routine or sleep schedule is interrupted, individuals with bipolar disorder often have difficulty recovering and are more likely to develop new manic or depressive episodes. Researchers have long noted this connection between bipolar disorder and circadian rhythms and continue to investigate it. Two studies presented at the annual meeting of the American College of Neuropsychopharmacology (ACNP), which is meeting this week, connect circadian rhythms with bipolar disorder and illustrate the implications of this link for treatment options.
A group of researchers, headed by Dr. Ellen Frank of the University of Pittsburgh School of Medicine, studied the effect of two different treatment approaches in combination with medication, usually lithium, on 175 adults with bipolar disorder. In interpersonal and social rhythm therapy, participants monitored and recorded the consistency of their daily routines, including when they slept, ate, and engaged in physical activity. The second approach focused on clinical management of the individual’s moods as well as the side effects of medication. Participants using interpersonal and social rhythm therapy went longer without a new manic or depressive episode than those using the clinical management approach, which indicates that patients can help keep their symptoms at bay by regulating their daily activities and sleep patterns.
A second study presented at the meeting, was published in the March edition of Proceedings of the National Academy of Sciences, and reported on the circadian rhythms of mice. The researchers, led by Dr. Colleen McClung of the University of Texas Southwest Medical Center, altered the clock gene, which controls circadian rhythms in mice. This caused the mice to exhibit many behaviors similar to those experienced during a manic episode, including hyperactivity, decreased need to sleep, poor judgement, and sensitivity to the effects of cocaine and sugar. The researchers were able to diminish these symptoms by giving the mice lithium, the medication most commonly used for treating bipolar disorder. Additionally, when the researchers injected a synthetic version of the clock gene into the region of the brain responsible for reward functions, the mutated mice resumed their normal behavior.
These studies provide further evidence of the connection between circadian rhythms and bipolar disorder, and future research should further explore this link. As we gain more information about the factors that contribute to bipolar disorder and affect its symptoms, we can utilize the most effective approaches in treating the disorder. Almost six million Americans suffer from bipolar disorder, and continued research should allow us a better understanding of the circumstances that make patients vulnerable to manic and depressive episodes.
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