Introduction: Depression is a risk factor and possible prodromal symptom of Alzheimer's disease (AD), but little is known about subsequent risk of developing depression in persons with AD.
Methods: National matched cohort study was conducted of all 129,410 persons diagnosed with AD and 390,088 with all-cause dementia during 1998-2017 in Sweden, and 3,900,880 age- and sex-matched controls without dementia, who had no prior depression. Cox regression was used to compute hazard ratios (HRs) for major depression through 2018.
Results: Cumulative incidence of major depression was 13% in persons with AD and 3% in controls. Adjusting for sociodemographic factors and comorbidities, risk of major depression was greater than two-fold higher in women with AD (HR, 2.21; 95% confidence interval [CI], 2.11-2.32) or men with AD (2.68; 2.52-2.85), compared with controls. Similar results were found for all-cause dementia.
Discussion: Persons diagnosed with AD or related dementias need close follow-up for timely detection and treatment of depression.
Highlights: In a large cohort, women and men with AD had >2-fold subsequent risk of depression.Risks were highest in the first year (>3-fold) but remained elevated ≥3 years later.Risk of depression was highest in persons aged ≥85 years at AD diagnosis.Persons with AD need close follow-up for detection and treatment of depression.
Keywords: Alzheimer disease; cohort studies; dementia; depression; mental health.
© 2024 The Authors. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals LLC on behalf of Alzheimer's Association.