Objectives Anxiety and depression are common and associated with higher use of general healthcare services. The aims of this systematic review were to (1) estimate the prevalence of anxiety and depression in adults who are high or costly users of general healthcare services in comparison to routine users and (2) estimate the magnitude of healthcare costs associated with the presence of anxiety and depression. Design Systematic review of the available literature. Data sources MEDLINE, PsycINFO, EMBASE, CINAHL, PROSPERO and Cochrane Library were systematically searched without language restriction from inception to 1 April 2019 and updated on 25 October 2022, 16 October 2024 and 18 February 2026. Eligibility criteria Eligible studies described adults aged ≥18 years who were defined as high or costly general healthcare users and where the prevalence and/or associated costs of anxiety and/or depression were quantified. Data extraction and synthesis Three reviewers independently extracted information on study characteristics, exposure and outcomes. Results From the 38 412 identified articles, 27 studies from 10 countries (in Europe, North America and Asia) involving 6 145 907 participants met eligibility criteria and were included. There were wide variations in the estimated prevalence of anxiety (3.8–67.2%) and depression (4.7–77.9%) among high healthcare users. The prevalence of both disorders was higher among high healthcare users than routine users in all studies with non-high user comparator groups. Only four studies investigated healthcare costs associated with depression. These uniformly reported that general healthcare costs are higher for those with depression than those without. No studies investigated costs associated with anxiety. Conclusions Anxiety and depression are over-represented among high or costly healthcare users, although accurate quantification of the magnitude of difference is precluded by significant methodological heterogeneity and variability in definitions used. Improved identification of covert mental health problems is essential for the provision of effective interventions for patients and healthcare expenditure reduction. Future research should prioritise a standardised approach, with agreed definitions for high and/or costly healthcare use in different contexts. PROSPERO registration number CRD42018102628.
Romeu et al. (Fri,) studied this question.