Abstract
<sec> <title>BACKGROUND</title> <p>Family caregivers provide much of the day-to-day care and support to people living with dementia. In this population, depression is common, yet prevalence estimates vary widely. This variation partly reflects inconsistent use of the term depression to describe distinct outcomes: depressive disorders identified by structured or semi-structured diagnostic interviews and clinically relevant depressive symptoms defined by rating-scale cutoffs. These outcomes are related but should not be treated as equivalent.</p> </sec> <sec> <title>OBJECTIVE</title> <p>This systematic review/meta-analysis aims to estimate separately the prevalence of depressive disorders and clinically relevant depressive symptoms among adult family caregivers of people with dementia, and to examine variation by assessment method, depression instrument, cutoff, caregiver characteristics, care context, and study characteristics.</p> </sec> <sec> <title>METHODS</title> <p>We will conduct a systematic review and meta-analysis of English-language studies published since January 1, 2000, searching PubMed, CINAHL, Scopus, and the Web of Science. Where feasible, backward citation searching and forward citation tracking will also be performed. Eligible studies will include unpaid adult family caregivers providing direct care or support to relatives, spouses, or partners with dementia; studies of paid or professional caregivers will be excluded. The primary outcomes will be the prevalence of (1) depressive disorder based on structured or semi-structured diagnostic interviews or established diagnostic criteria and (2) clinically relevant depressive symptoms based on validated depression measures with clearly reported cut-off values; outcomes will be analyzed separately. Where sufficient data are available, ultra-brief screening tools (e.g., Patient Health Questionnaire-2) will be synthesized separately from longer depression scales. Two reviewers will independently screen studies, extract data, and assess risk of bias using the Joanna Briggs Institute Checklist for Prevalence Studies. Where appropriate, pooled prevalence estimates with 95% confidence intervals will be calculated using random-effects generalized linear mixed models with a logit link. Heterogeneity will be assessed using Cochran’s Q, I², between-study variance, and prediction intervals, as appropriate, and prespecified subgroup, meta-regression, and sensitivity analyses will explore potential sources of heterogeneity.</p> </sec> <sec> <title>RESULTS</title> <p>The protocol was prospectively registered on the Open Science Framework before formal screening. The database search, study selection, data extraction, risk-of-bias assessment, and meta-analysis will be conducted post-registration. Results will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. The OSF-registered systematic review is expected to be completed by March 2027.</p> </sec> <sec> <title>CONCLUSIONS</title> <p>This review will provide separate prevalence estimates for depressive disorders and clinically relevant depressive symptoms among family caregivers of people with dementia. Distinguishing diagnostic interview-based disorders from scale-based symptom classifications and detailing instruments and cutoffs may clarify evidence for research, clinical assessment, and service planning.</p> </sec> <sec> <title>CLINICALTRIAL</title> <p>OSF registration number: 10.17605/OSF.IO/QZES3.</p> </sec>