The importance of sleep cannot be underemphasized. Getting insufficient quality or quantity sleep has been linked to a wide range of health problems, ranging from increased risk of obesity and strike to reduced cognitive abilities. Now comes word that the quantity of sleep that we get, whether too little or too much, may be directly tied to the incidence of depression. The results of two different studies were recently published in the journal Sleep, and are getting a great deal of attention.
In the first study, a group of nearly 2,000 adult twins were followed, yielding the discovery of a gene by environment interaction that showed a relationship between the amount of time that a person slept and their experience of depressive symptoms. Those twins who slept for periods between the recommended seven and 8.9 hours of sleep per night showed heritability of depressive symptoms of just 27 percent. Those who slept five hours or more than ten displayed heritability of depressive systems of a remarkable 53 to 49 percent respectively.
The study’s principal investigator, Nathaniel Watson, M.D. of the University of Washington Medicine Sleep Center in Seattle, said, “We were surprised that the heritability of depressive symptoms in twins with very short sleep was nearly twice the heritability in twins sleeping normal amounts of time. Both short and excessively long sleep durations appear to activate genes related to depressive symptoms. The study’s findings suggest that optimizing sleep may be one way to maximize the effectiveness of treatments for depression, such as psychotherapy.”
The other study involved a group of 4,175 children between the ages of eleven and seventeen. The study found that those who slept six hours or less per night had a much increased risk of major depression. The problem is of particular concern because depression increases the risk for decreased sleep in adolescents. According to principal investigator Robert E. Roberts, professor of behavioral sciences in the School of Public Health at the University of Texas Health Science Center in Houston, Texas, “These results are important because they suggest that sleep deprivation may be a precursor for major depression in adolescents, occurring before other symptoms of major depression and additional mood disorders. Questions on sleep disturbance and hours of sleep should be part of the medical history of adolescents to ascertain risk.”
According to the American Academy of Sleep Medicines president, Dr. M. Safwan Badr, “Healthy sleep is a necessity for physical, mental and emotional well-being. This new research emphasizes that we can make an investment in our health by prioritizing sleep.” It is strongly recommended that practitioners seeing patients for symptoms of depression spend the time to investigate sleep duration and approach their treatment with an eye to normalizing and improving sleep quality and sleep quantity.