Background: The prevention of mental disorders and promotion of mental health and well-being are growing fields. Whether mental health promotion and prevention interventions provide value for money in children, adolescents, adults, and older adults is unclear. The aim of the current study is to update 2 existing reviews of cost-effectiveness studies in this field in order to determine whether such interventions are cost-effective. Methods and findings: Electronic databases (including MEDLINE, PsycINFO, CINAHL, and EconLit through EBSCO and Embase) were searched for published cost-effectiveness studies of prevention of mental disorders and promotion of mental health and well-being from 2008 to 2020. The quality of studies was assessed using the Quality of Health Economic Studies Instrument (QHES). The protocol was registered with PROSPERO (# CRD42019127778). The primary outcomes were incremental cost-effectiveness ratio (ICER) or return on investment (ROI) ratio across all studies. A total of 65 studies met the inclusion criteria of a full economic evaluation, of which, 23 targeted children and adolescents, 35 targeted adults, while the remaining targeted older adults. A large number of studies focused on prevention of depression and/or anxiety disorders, followed by promotion of mental health and well-being and other mental disorders. Although there was high heterogeneity in terms of the design among included economic evaluations, most studies consistently found that interventions for mental health prevention and promotion were cost-effective or cost saving. The review found that targeted prevention was likely to be cost-effective compared to universal prevention. Screening plus psychological interventions (e.g., cognitive behavioural therapy [CBT]) at school were the most cost-effective interventions for prevention of mental disorders in children and adolescents, while parenting interventions and workplace interventions had good evidence in mental health promotion. There is inconclusive evidence for preventive interventions for mental disorders or mental health promotion in older adults. While studies were of general high quality, there was limited evidence available from low- and middle-income countries. The review was limited to studies where mental health was the primary outcome and may have missed general health promoting strategies that could also prevent mental disorder or promote mental health. Some ROI studies might not be included given that these studies are commonly published in grey literature rather than in the academic literature. Conclusions: Our review found a significant growth of economic evaluations in prevention of mental disorders or promotion of mental health and well-being over the last 10 years. Although several interventions for mental health prevention and promotion provide good value for money, the varied quality as well as methodologies used in economic evaluations limit the generalisability of conclusions about cost-effectiveness. However, the finding that the majority of studies especially in children, adolescents, and adults demonstrated good value for money is promising. Research on cost-effectiveness in low-middle income settings is required. Trial registration: PROSPERO registration number: CRD42019127778.

Loneliness and social isolation can occur at all stages of the life course and are recognized as a global health priority. The aim of this study was to review existing literature on the economic costs associated with loneliness and social isolation as well as evidence on the cost-effectiveness of interventions to prevent or address loneliness and social isolation.

Objective: The aim of this project was to detail the costs associated with the high prevalence mental disorders (depression, anxiety-related and substance use) in Australia, using community-based, nationally representative survey data. Methods: Respondents diagnosed, within the preceding 12 months, with high prevalence mental disorders using the Confidentialised Unit Record Files of the 2007 National Survey of Mental Health and Wellbeing were analysed. The use of healthcare resources (hospitalisations, consultations and medications), productivity loss, income tax loss and welfare benefits were estimated. Unit costs of healthcare services were obtained from the Independent Hospital Pricing Authority, Medicare and Pharmaceutical Benefits Scheme. Labour participation rates and unemployment rates were determined from the National Survey of Mental Health and Wellbeing. Daily wage rates adjusted by age and sex were obtained from Australian Bureau of Statistics and used to estimate productivity losses. Income tax loss was estimated based on the Australian Taxation Office rates. The average cost of commonly received Government welfare benefits adjusted by age was used to estimate welfare payments. All estimates were expressed in 2013–2014 AUD and presented from multiple perspectives including public sector, individuals, private insurers, health sector and societal. Results: The average annual treatment cost for people seeking treatment was AUD660 (public), AUD195 (individual), AUD1058 (private) and AUD845 from the health sector’s perspective. The total annual healthcare cost was estimated at AUD974m, consisting of AUD700m to the public sector, AUD168m to individuals, and AUD107m to the private sector. The total annual productivity loss attributed to the population with high prevalence mental disorders was estimated at AUD11.8b, coupled with the yearly income tax loss at AUD1.23b and welfare payments at AUD12.9b. Conclusion: The population with high prevalence mental disorders not only incurs substantial cost to the Australian healthcare system but also large economic losses to society.

Background: Eating disorders are serious mental disorders and are associated with substantial economic and social burden. The aim of this study is to undertake a systematic review of the cost-effectiveness studies of both preventive and treatment interventions for eating disorder. Method: Electronic databases (including the Cochrane Controlled Trial Register, MEDLINE, PsycINFO, Academic Search Complete, Global Health, CINAHL complete, Health Business Elite, Econlit, Health Policy Reference Center and ERIC) were searched for published cost-effectiveness studies of eating disorder prevention and treatment including papers published up to January 2017. The quality of studies was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. Results: In all, 13 studies met the review inclusion criteria as full cost-effectiveness studies and 8 were published since 2011. The studies included three modelled and one trial-based study focused on prevention, two trial-based and one modelled study for anorexia nervosa treatment and three trial-based studies for bulimia nervosa treatment. The remaining studies targeted binge-eating disorder or non-specific eating disorder treatment. The average percent of CHEERS checklist items reported was 71% (standard deviation 21%). Eating disorder interventions were mainly cost-saving or more effective and more costly compared to comparators; however, some results did not reach statistical significance. In the two studies that achieved 100% CHEERS checklist, one study reported that a cognitive dissonance intervention might be cost-effective for prevention of anorexia nervosa and bulimia nervosa with a 90% participation rate and the second study supported lisdexamfetamine to be cost-effective in the treatment of binge-eating disorder. Insufficient evidence for long-term cost-effectiveness (e.g. over 2 years) was found. Conclusion: Cost-effectiveness studies in eating disorder appear to be increasing in number over the last 6 years. Findings were inconsistent and no firm conclusion can be drawn with regard to comparative value-for-money conclusions. However, some promising interventions were identified. Further research with improved methodology is required.