A front-page headline of the Nov. 19 New York Times read: “Sleep Therapy Seen as an Aid to Depression.” A few days later, an editorial on the topic chimed in with: “Most psychiatrists have very little training in dealing with insomnia. As the head of the Duke University study told Mr. [Benedict] Carey, psychiatrists have largely ignored the body’s complex circadian cycles.”
Psychiatry’s loss may be neuroscience’s gain, however, as recent advances in understanding the relationship among the circadian rhythms, the brain’s hypothalamus,and a mutated gene suggest. The topic is the focus of “Migraine and Sleep: New Connections,” our Cerebrum feature for December.
Co-authored by Andrew H. Ahn, M.D., Ph.D., and Peter Goadsby, M.D., Ph.D., the story references a multicenter study headed by Louis Ptácek, a leading headache expert and researcher at the University of California, San Francisco. Ptácek is a colleague of Goadsby, who is director of the University of California, San Francisco Headache Center and also a leading headache expert and researcher. Ahn, an assistant professor of neurology at the University of Florida’s College of Medicine, trained as a postdoctoral fellow and resident at the University of California, San Francisco.
The placement of the Times story speaks to the importance of sleep and mental health. Sleep and sleep-minded problems play a role in a large number of human disorders and affect almost every field of medicine. Depression is the most common mental disorder, affecting some 18 million Americans in any given year, according to government figures, and more than half of those people also have insomnia. Migraine, which is classified as a syndrome, is close behind in its impact on people and the economy, and no less important. According to the American Migraine Foundation, medical care for the 36 million Americans who suffer from migraine accounts for up to an estimated $30 billion per year; American employers lose more than $13 billion each year as a result of 113 million lost work days due to migraine; nearly half of all migraine sufferers are never diagnosed and the majority do not seek medical care for their pain.
Our story references geneticists who dissected the molecular pathways related to circadian rhythm in humans. They found that a mutation of the period gene that regulates the daily rhythm of activity in fruit flies is a key player in how the hypothalamus keeps track of the daily rhythm that drives our innate pattern of wakefulness and activity. “The significance of a common biochemical pathway underlying circadian rhythm throughout evolution cannot be overstated,” write the authors.
Members of a Vermont family with a history of both migraine and a rare sleep disorder were found to exhibit the mutated gene. When the mutated gene was implanted in mice, the mice litters exhibited both features associated with migraine and the sleep disorder.
While much work still needs to be done in the way of treatment or prevention, the finding represents a significant step. Robert Shapiro, professor of neurology at the University of Vermont, and an author of the study, told USA Today that “this is the first gene among the genes that have been found for migraine that isn’t a code for structural protein… it’s actually a regulator of other proteins.”