OBJECTIVE: Depression is often associated with disruptions in sleep and circadian rhythms. We aimed to confirm these relationships via actigraphic assessment in a large, population-based sample and test whether sex moderates these relationships.
METHODS: A total of 418 participants (age = 35-85 years, mean [standard deviation] = 57.04 [11.47]) completed questionnaires and 1 week of actigraphy, used to calculate sleep and rest-activity statistics including mesor (mean activity level), amplitude (height of rhythm), and acrophase (time of day that rhythm peaks).
RESULTS: Depressive symptoms, assessed via Center for Epidemiologic Studies Depression Scale, were associated with disrupted sleep and rest-activity rhythms. Furthermore, men demonstrated longer sleep onset latency (SOL, B = -13.28, p < .001), longer wake time after sleep onset (B = -6.26, p < .01), lower sleep efficiency (B = 5.91, p < .001), and lower total sleep time (TST, B = 33.16, p < .001) than women. Sex moderated the relationship between depression and SOL, TST, mesor, and amplitude; sex-stratified models revealed that higher depression scores were associated with greater SOL (B = 1.05, p < .001) and less TST (B = -0.87, p < .10) for women with higher depressive symptoms, but lower mesor (B = -1.75, p < .01) and amplitude (B = -1.94, p < .01) for men with higher depressive symptoms.
CONCLUSIONS: Depressive symptoms were related to disrupted sleep continuity and rest-activity rhythms in this population-based sample; however, these relationships differed by sex. Women with greater depressive symptoms exhibited difficulty with sleep continuity, whereas men with greater depressive symptoms demonstrated disruption throughout the 24-hour rhythm.
