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Research identifies biomarkers of improved MDD-related hypersomnia following exercise

Improvement in hypersomnia following exercise among individuals with major depressive disorder is related to changes in inflammatory markers and brain-derived neurotrophic factor, according to study findings in Translational Psychiatry.

“Poor sleep quality is a common symptom of [major depressive disorder (MDD)] and is one of the most prevalent residual symptoms following antidepressant treatment. Importantly, these residual sleep disturbances are predictive of relapse in following MDD remission. As a result, understanding the biological mechanisms related to changes in sleep are important steps in moving toward optimal treatment of MDD,” Chad Rethorst, PhD, of the University of Texas Southwestern Medical Center, in Dallas, and colleagues wrote.

Chad Rethorst

To identify markers of change in hypersomnia and insomnia associated with MDD following exercise, researchers randomly assigned individuals with non-remitted MDD to one of two aerobic exercise conditions: 16 kilocalories per kilogram of body weight per week or 4 kilocalories per kilogram of body weight for 12 weeks. Sleep quality was assessed via four sleep-related items on the Inventory of Depressive Symptomatology. Blood samples were collected before and after the 12-week intervention to determine inflammatory cytokines, interleukin-1β (IL-1β), IL-6 and brain-derived neurotrophic factor.

Reductions in hypersomnia were associated with reductions in brain-derived neurotrophic factor (P = .029) and IL-1β (P = .002).

Changes in brain-derived neurotrophic factor and IL-1β were not associated with changes in insomnia; however, lower levels of IL-1β at baseline predicted greater improvements in insomnia (P = .05).

“The results of the current analysis implicate pro-inflammatory cytokines and [brain-derived neurotrophic factor] in exercise-induced improvements in sleep quality but also suggest that other biological mechanisms are likely involved. The fact that changes in IL-1β and [brain-derived neurotrophic factor] were only related to changes in hypersomnia further support the need to identify biological markers that differentiate across different symptom profiles,” Rethorst and colleagues wrote. “These findings highlight the need for further research examining the biological mechanisms linking exercise and sleep. Given the importance of treating sleep in improving treatment outcomes, future work aimed at understanding these biological mechanisms in MDD is especially important.” – by Amanda Oldt

Disclosure: Rethorst reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.