SLEEP DURATION AND DEPRESSIVE SYMPTOMS: A GENE-ENVIRONMENT INTERACTION
Sleep Duration and Depressive Symptoms: A Gene-Environment Interaction
Nathaniel F. Watson, MD, MSc1,2,3; Kathryn Paige Harden, PhD4; Dedra Buchwald, MD5; Michael V. Vitiello, PhD6,3; Allan I. Pack, MBChB, PhD7; Eric Strachan, PhD6; Jack Goldberg, PhD5,8
1Department of Neurology, University of Washington, Seattle, WA; 2UW Medicine Sleep Center, University of Washington, Seattle, WA; 3Center for Research on the Management of Sleep Disturbances, University of Washington, Seattle, WA; 4Department of Psychology, University of Texas at Austin, Austin, TX; 5Department of Epidemiology, University of Washington, Seattle, WA; 6Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA; 7Division of Sleep Medicine/Department of Medicine and Center for Sleep and Circadian Neurobiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA; 8Vietnam Era Twin Registry, VA Epidemiologic Research and Information Center, Seattle, WA
We used quantitative genetic models to assess whether sleep duration modifies genetic and environmental influences on depressive symptoms.
Participants were 1,788 adult twins from 894 same-sex twin pairs (192 male and 412 female monozygotic [MZ] pairs, and 81 male and 209 female dizygotic [DZ] pairs] from the University of Washington Twin Registry. Participants self-reported habitual sleep duration and depressive symptoms. Data were analyzed using quantitative genetic interaction models, which allowed the magnitude of additive genetic, shared environmental, and non-shared environmental influences on depressive symptoms to vary with sleep duration.
Within MZ twin pairs, the twin who reported longer sleep duration reported fewer depressive symptoms (ec = -0.17, SE = 0.06, P < 0.05). There was a significant gene × sleep duration interaction effect on depressive symptoms (a'c = 0.23, SE = 0.08, P < 0.05), with the interaction occurring on genetic influences that are common to both sleep duration and depressive symptoms. Among individuals with sleep duration within the normal range (7-8.9 h/night), the total heritability (h2) of depressive symptoms was approximately 27%. However, among individuals with sleep duration within the low (< 7 h/night) or high (≥ 9 h/night) range, increased genetic influence on depressive symptoms was observed, particularly at sleep duration extremes (5 h/night: h2 = 53%; 10 h/night: h2 = 49%).
Genetic contributions to depressive symptoms increase at both short and long sleep durations.
Watson NF; Harden KP; Buchwald D; Vitiello MV; Pack AI; Stachan E; Goldberg J. Sleep duration and depressive symptoms: a gene-environment interaction. SLEEP 2014;37(2):351-358.