Disrupted sleep and risk of depression in later life: A prospective cohort study with extended follow up and a systematic review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational longitudinal cohort studies alongside an original prospective cohort study.
PubMed 35490880 · doi:10.1016/j.jad.2022.04.133
What was done
A prospective cohort study followed community-dwelling men aged 70–89 years in Western Australia for up to 17 years (baseline 2001–2004 through 2018 or death). Men with prevalent depression (437/5,547) were excluded, leaving 4,561 depression-free participants. Incident depression was identified by a PHQ-9 score ≥ 10 at 2–3 year follow-up waves or a depressive disorder diagnosis in health administrative records. A systematic review and meta-analysis of longitudinal studies investigating sleep disruption and late-life depression was also conducted following PRISMA guidelines.
What was found
At baseline, 3,441 of 5,547 men reported sleep difficulties (2,693 of the 4,561 depression-free men). Sleep problems were associated with an increased risk of incident depression (hazard ratio = 1.67, 95% CI = 1.39–2.00), remaining unchanged after adjustment for age, place of birth, education, smoking, and physical frailty. The systematic review identified 14 additional longitudinal studies; meta-analysis yielded a pooled risk ratio of 1.82 (95% CI = 1.69–1.97) for depression.
Why it matters
By tracking depression-free older adults over 17 years and combining results with external longitudinal cohorts, this study strengthens the evidence that sleep disturbances precede the onset of late-life depression rather than acting purely as a prodromal symptom.
Limits
The prospective cohort included only older men, limiting generalizability to women. Sleep difficulties were determined through self-report rather than objective measures such as actigraphy or polysomnography. The authors also noted that the overall quality of available evidence across the included meta-analysis studies was suboptimal.
Cited by
- supports Sleep deprivation is associated with and can trigger depression.