Mental illness is the leading cause of disability in the UK, accounting for >20% of the disease burden, with an annual cost of £70-100 billion to the economy (Department of Health, 2014). In 2014, 1-in-6 adults in England had a common mental disorder (McManus et al., 2016).

With so much attention focussed on the need to improve the treatment of mental illness and the inadequacy of NHS funding for mental health services, it is all too easy to overlook the public health perspective, with its focus on the prevention of mental illness and improvement of population mental health.

This review in the high-impact US journal “Annual Review of Public Health”, describes the historical development of population-based approaches to improving mental health in the USA, before going on to give an overview of their evidence base and current practice in the USA.

Methods

This is a wide-ranging narrative review of selected literature and US Public Health Department engagement data on population-based mental health activities.

Results

The review makes a strong case for the potential of population-based approaches to improve public mental health. The section that will probably be of most interest to a non-USA audience is the review of effective interventions; these are categorised into three domains:

1. Social, economic and environmental policy (e.g. to reduce adverse childhood experiences (ACEs); to tackle financial and housing insecurity);
2. Public health practice (e.g. communication campaigns to reduce stigma) and
3. Healthcare (e.g. enhancing the effectiveness of clinical services; employing “paraprofessionals” to support the social needs of people with mental illness).

Potential approaches highlighted include built environment interventions to reduce noise and light exposure (and thereby improve sleep) and enhancement of green-space (supported by evidence from a cluster RCT); state policy interventions around adequate minimum wages and income tax credits; public housing subsidies and legislation to support same-sex marriages.

The authors flag the disparity of focus on mental health compared to physical health. Whereas 60% of local health departments in the US engage in physical chronic disease prevention programmes, the equivalent figure for mental illness prevention is a mere 20%. But there is growing interest in integrating mental health into public health practice and policy-making.

Conclusions

The authors conclude by highlighting the need for:

a collective shift in thinking at the societal level – from a view that conceptualizes mental health as an individual issue that is exclusively within the purview of psychologists and psychiatrists to one that conceptualizes mental health as a public health issue.

They flag the challenges posed by structural racism, climate change, high levels of diagnosed mental illness amongst prison populations and social media (but rightly acknowledge the opportunities of smartphone-based interventions). Whilst they recognise the need for more research, they feel that:

the state of the science is sufficient to recommend specific courses of action to improve population mental health.

Strengths and limitations

The main strength of this review is its wide-ranging scope; putting current population mental health practice in the USA in an historical perspective, highlighting key risk factors and some promising areas for prevention. The authors helpfully define some of the terminology used in this area, so will serve as a useful primer for someone new to the field.

However, a reader looking for clear, evidence-based guidance to inform local or national prevention priorities will be disappointed. It is unclear how the authors selected some interventions for focus and yet overlooked important influences on population mental health such as alcohol (Xuan et al., 2016), gambling (Reith et al., 2019) and job loss (Moore et al., 2017). They do say they excluded addiction problems, but the role of alcohol on common mental disorders is well recognised.

Settings based mental health promotion (e.g. in schools, universities and the workplace) was not included in the review, the authors acknowledge this as a limitation, but a brief summary of the evidence in the area would have strengthened the review, as this is a field with a rapidly evolving evidence-base.

Implications for practice

Population mental health is influenced by a wide range of factors, many unrelated to the availability of healthcare services. It is therefore essential for policy makers across a range of Government Departments to consider not only the adequacy of funding of health services, but also the impact of their past and planned policies on population mental health, in view of the impact of poor mental health, not least on people’s lives, but also the economy. Recent adverse trends in the mental health of young people in the UK (Gunnell et al., 2018), point to the need for joined up strategies across Government Departments with responsibility for education, employment, media, welfare benefits, regulating gambling, alcohol pricing and the environment as well as Health and Social Care.

The potency of population-based approaches to improving public health has long been recognised (Rose, 1985). Policy makers and public health specialists wanting to improve the mental health of their population now have a range of interventions to choose from, some of these are highlighted in this review. What they chose will in part depend on an assessment of local needs, and so local needs assessment and surveillance to identify the impact of interventions and emerging concerns is important. Decision making would be helped by an economic appraisal of the most cost-effective and feasible options.

Statement of interests

David Gunnell is a member of England’s National Suicide Prevention Strategy Advisory Group. He is also a member of Movember’s Global Advisory Committee and the Samaritans Policy, Partnerships and Research Committee.

Links

Primary paper

Purtle, J., Nelson, KL, Counts, NZ and Yudell, M. (2020). Population-based approaches to mental health: history, strategies and evidence. Annu. Rev. Public Health; 41: 21.1-21.21.

Other references

Department of Health. (2014). Annual Report of the Chief Medical Officer 2013: Public Mental Health Priorities: Investing in the Evidence. https://www.gov.uk/government/publications/chief-medical-officer-cmo-annual-report-public-mental-health

Gunnell, D., Kidger, J. and Elvidge, H. (2018). Adolescent mental health in crisis. BMJ 2018;361:k2608. 10.1136/bmj.k2608

McManus, S., Bebbington, P., Jenkins, R. and Brugha, T. (2016). Mental health and wellbeing in England: Adult Psychiatric Morbidity Survey 2014. Leeds: NHS Digital.

Moore TH, Kapur N, Hawton K, Richards A, Metcalfe C, Gunnell D. (2017) Interventions to reduce the impact of unemployment and economic hardship on mental health in the general population: a systematic review. Psychol Med; 47(6):1062-1084.

Reith, G., Wardle, H. and Gilmore, I. (2019). Gambling harm: a global problem requiring global solutions. Lancet 394: 1212-3

Rose, G. (1985). Sick individuals and sick populations. International Journal of Epidemiology, Volume 14 (1): 32–38,

Xuan, Z., Naimi, TS, Kaplan, MS, Bagge, CL and Few, LR (2016). Alcohol Policies and Suicide: A Review of the Literature. Alcohol Clin Exp Res, Vol 40, No 10: pp 2043–2055.

In the UK, Public Health England provide useful resources to help organisations to improve population mental health, and improve the lives of people with mental health problems.

Photo credits

• Photo by Christine Roy on Unsplash
• Photo by sasan rashtipour on Unsplash
• Photo by Kelly Sikkema on Unsplash