Depression-Related Sleep Problems May Be Relieved With Exercise
Two recently identified blood biomarkers have allowed researchers to discover that aerobic exercise can significantly reduce excessive daytime sleepiness, one of the most common symptoms of depression.
The researchers from the University of Texas Southwestern Medical Center in Dallas discovered two unique biological markers indicative of excessive daytime sleepiness, formally known as hypersomnia.
Hypersomnia is characterized by sleeping too much at night, as well as excessive daytime sleepiness and is a frequent symptom of major depressive disorder.
After identifying the biomarkers, the researchers also found that aerobic exercise lowered the levels of both biomarkers and was linked to reduced excessive sleepiness.
“Hypersomnia, as well as insomnia, have been linked in the development, treatment, and recurrence of depression,” said senior author Dr. Madhukar Trivedi. “Sleep disturbances are also some of the most persistent symptoms in depression. Identifying these biomarkers, combined with new understanding of the important role of exercise in reducing hypersomnia, have potential implications in the treatment of major depressive disorder.”
Individuals who experience hypersomnia feel the need to nap repeatedly throughout the day, even at inappropriate times such as during work or meals. They also frequently have difficulty waking from long sleep and often feel disoriented when first walking.
The condition is also linked to anxiety, increased irritation, decreased energy, restlessness, slow thinking, slow speech, loss of appetite, hallucinations, and memory difficulty. These can also severely hamper a person’s ability to function in family, social, occupational, or other settings.
To identify the biomarkers, the researchers used samples provided by participants in the Treatment with Exercise Augmentation for Depression (TREAD) study, who were randomly assigned to two types or aerobic exercise to determine the effects of exercise on depression.
The TREAD study included over 100 subjects ages 18 to 70 who were diagnosed with depression.
This allowed the researchers to assess the levels of four biomarkers in blood including brain-derived neurotrophic factor (BDNF), inflammatory cytokines called tumor necrosis factor alpha, and two interleukins, IL-1β and IL-6.
From these tests, the team saw that reductions in two biomarkers, BDNF and IL-1β, are linked to reductions in hypersomnia.
“Identification of biomarkers that uniquely predict or correlate with improvements in hypersomnia and insomnia is an important step toward more effective treatment of MDD [major depressive disorder],” said lead author Dr. Chad Rethorst, assistant professor of psychiatry with University of Texas Southwestern’s Center for Depression Research and Clinical Care.
One of the most notable findings from the study is that the two biomarkers appear to be specific for hypersomnia, rather than other sleep problems. Reductions in the biomarkers were not tied to changes in insomnia.