Study objectives: The objective of this study was to examine the associations between the temporal and severity characteristics of sleep disturbance and subsequent depression in community-dwelling older adults.
Design: A prospective cohort study with assessment of sleep disturbance and depression at baseline and across 2 years of follow-up.
Setting: Three urban communities in the United States.
Participants: Community-dwelling older adults in whom prior depression (n = 145), current depression (n = 68), or never mentally ill (n = 206) were diagnosed at the baseline assessment.
Measurements and results: Major depression at year 2, defined by the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders. Among patients with either a depression history or current depression at baseline, persistent sleep disturbance throughout year 1 was associated with persistent or recurrent depression at year 2, after adjustment for group status, antidepressant and hypnotic sedative use, severity of depressive symptoms, chronic medical burden, and sociodemographic variables (adjusted odds ratio = 5.20, 95% confidence interval [CI] = 1.16 to 23.29). Among those who were not depressed at year 1, persistent sleep disturbance throughout year 1 predicted depression recurrence during year 2 (adjusted hazards ratio = 16.05, CI = 1.21 to 213.06), independent of the severity of sleep disturbance. None of the older adults who were never mentally ill developed a depression.
Conclusions: Persistent sleep disturbance during a year-long period is associated with depression the following year. Among older adults with prior depression, identification of those with persistent sleep disturbance may optimize the efficacy of sleep related interventions to improve depression remission and/or prevent late-life depression.
Keywords: Sleep disturbance; aging; depression.