How many of us in our training considered how public health could be the cornerstone for the prevention of mental health problems? For most, the focus was on diagnosis and treatment, and the possibility of primary prevention at a population level was not particularly on our horizon. Yet if our experience of cigarette smoking has taught us anything, the most effective strategy for improving health is preventing the disorder in the first place. Can we apply this mind-set to mental disorder? Geoffrey Rose described the prevention paradox, whereby targeted actions designed to improve health in a subgroup of the population were less effective than population-wide measures which impacted on the whole population (Rose, Reference Rose1985). In this issue, population-level interventions are discussed. However while we may discuss it, the extreme dearth of public health doctors whose area of expertise is public mental health is very notable. There is a symmetry here – for among psychiatrists there are none with formal public health training. Clearly, there is a gap in the market which trainees should consider.

The articles in this issue are a shot across the bows on this topic of public mental health. James Lucey (pp. 2–5) outlines how we are at a crossroads of psychiatric and medical care where the sustainability of our health systems need to be considered, as well as providing support for public health approaches. These approaches could shift funding to primary and secondary prevention - but he asks whether we have pubic and political support for this? Indeed, do mental health professionals support this approach? Where do we invest the limited funding for mental health?

Ashton (pp. 9–12) outlines the history of mental health services development internationally and questions how we will protect the global population from mental illness with a focus on periods of emergency such as the recent COVID-19 pandemic. Clearly, the challenges to public mental health at a population level are growing and in this issue the risks associated with the climate emergency (Power et al., pp. 6–8), cannabis use (Johnson-Fergusson et al., pp. 13–18), social media (Scully et al., pp. 31–42) and other online activity (Lonergan et al., pp 43–50) are all outlined.

Specific examples of positive outcomes that follow population-wide actions are described. For example, McTernan and colleagues (pp. 19–29) outline how a TV campaign resulted in increased emotional well-being and stigma reduction. Similarly, the approach of legislative action can be timely and effective at a population level. Smyth (pp. 89–96) outlines the positive effects of robust timely legislation on the pubic mental health risks associated with the sale of new psychoactive substances from ‘Headshops’. The benefits of such legislation are clearly evident; however, Barry, a public health physician, outlines the enormous challenges in moving from this type of advocacy and policy to legislation (pp. 103–106).

Gnanapragasam and colleagues (pp. 63–73) point to the need for clinicians to have clear advocacy roles and to work outside of their silos in order to develop integrated policies. This is consistent with the approach of ‘No Health without Public Mental Health’ endorsed by the Royal College of Psychiatrists (Royal College of Psychiatrists 2010). People with psychosis are 4.5 times more likely to die before the age of 75 years than those without mental disorders, equating to a reduced life expectancy by roughly 15–20 years, which is highlighted in the article by Byrne (pp. 74–83). This premature mortality, it’s causes, and 10 recommendations for action are the subject of a very informative perspective piece. Data such as this is critical to service development, and simple register-type information, such as age, gender, diagnoses, mortality, and morbidity, is almost entirely missing in Ireland. This point is made by Lynch and colleagues who report on a systematic review of Child and Adolescent Mental Health Services in Ireland (pp. 51-62).

Rose’s prevention paradox has shown that we need to act at the population level to optimise primary prevention in public health. Let’s act on this knowledge, apply it to public mental health, and in so doing improve public health for future generations. It’s a win-win approach for all.