Preventive psychiatry is public health

Public health includes preventing violence and protection against violence, healthy work practices, and empowered communities and citizens who take charge of their health. Public health actions should maximise quality of life and life expectancy in a non-stigmatising way and reduce inequalities.

This not a public health journal, but on reading this month's issue, a reader may wonder. There are research papers on gun laws, violence and risk prediction, different treatments for heroin addiction, e-treatments for alcohol misuse in students, studies on somatic and attention-deficit hyperactivity disorder (ADHD) dimensions of diagnosis, and social and environmental influences on delusions and recovery from them; and then, empowering carers and the public to better manage their concerns. All these papers seem to speak to the existing public health policies and priorities of Public Health England (https://www.gov.uk/government/organisations/public-health-england) that are now being addressed by cross-government and inter-agency agreements. For example, in the UK at least, local government is now responsible for commissioning substance misuse services. Over 10 years ago, the College produced a multi-agency best practice guide on treating coexisting mental illness and drug addiction. ^{Reference Banerjee, Clancy and Crome1} Updated guidance is needed given that there is now more research evidence and that substance misuse treatment is now commissioned and mostly provided outside health services. Studies like that of Byford et al (pp. ) set out the difficult trade-offs between the cost of an intervention and commissioners' concerns over what is affordable; often, these deliberations do not take account of the wider benefits to society and the criminal justice system, and may be more influenced by resource allocation and attitudes to drug addiction than by the scientific evidence. Byford et al embrace the need for decision-making tools that make the trade-offs in resource allocation explicit and invoke the influence of ‘willingness to pay’, a judgement that might be more important than the scientific assessment of clinical evidence. Overall, injected methadone might be preferred but injected heroin produces better outcomes for refractory heroin addiction. How widely is this finding going to be implemented by commissioners?

The brutality of acts of violence and violation is a public health concern which psychiatric research can inform, not only in cases of violent assault and murder, but also for child protection, preventing online grooming and sexual abuse, domestic violence, and perhaps even political violence. ^{Reference Bhui2} Only with better evidence can we replace the ‘moral panics’ and political precedents that often dictate policy, for example, around gun laws in the USA (Elson & Ferguson pp. ). Coid et al (pp. ) show that for those with a diagnosis of psychopathy, compared with no mental disorder or other types of personality disorder, there is very little value in risk prediction tools. It is rather reassuring that there remains some value in using such tools, given that violence prediction is so difficult and risk assessment tools are so interchangeable. ^{Reference Yang, Wong and Coid3} Delusions or overvalued ideas can motivate violence. Garety & Freeman (pp. ) set out the cognitive and biological, as well as the social and environmental causes of delusions, recommending that the antecedents of delusions are poor self-esteem, worry, powerlessness, inflexibility and insomnia. Could such antecedents also be found in delusions related to violence and so be targeted in communities, for example, to prevent gang violence as well as interpersonal and intergroup hostilities and prejudices? Showing an even greater role of the social and interpersonal environment in intervention, Garety & Freeman discuss that people who have carers respond better to cognitive-behavioural therapy for psychosis. ^{Reference Garety, Fowler, Freeman, Bebbington, Dunn and Kuipers4} Carer burden often goes unnoticed until there is a crisis, so preliminary results of better outcomes after using a self-support toolkit for carers show promise (Lobban et al, pp. ).

Patient and public empowerment lies at the heart of public health policies that promote population resilience as a preventive intervention. ^{Reference Bhui and Dinos5} Involving patients and the public in research has for a long time been regarded as a good thing, and now Ennis & Wykes (pp. ) show evidence of better recruitment and higher quality in research. Promoting self-help is a necessary element of empowerment and better resilience so that fewer people need care services. Alcohol use is common and excessive use is associated with suicide, mental disorders, worklessness, and a number of physical health problems leading to premature mortality. McCambridge et al's electronic self-help tool (pp. ) reduces risky alcohol use in university students. Stigma continues to prevent people from disclosing mental illness and seeking help, so self-help aids may be very useful; however, people still fear losing their jobs. Hendersons et al's pilot study (pp. ) shows that a decision tool for disclosure of mental illness at work can reduce decision conflict and may help retain employment.

Diagnosis is important in psychiatric practice, but how important is it in public health practice that aims to improve mental health and well-being? Several papers in this issue refer to the dimensional ways of understanding diagnosis, and it is as important to profile these dimensions in the population as in clinical settings, without considering them to be abnormal and extreme. The prevalence and implications of somatic symptoms and ADHD traits in populations are also discussed. Genetic studies reveal weaknesses in our diagnostic systems ^{Reference Craddock and Sklar6} and the recent findings of shared genetic aetiology for schizophrenia, depression, autism, ADHD and bipolar disorder promise better diagnostic systems and more effective care in the future. ⁷ If it is possible to find common phenotypic markers of the causes of mental disorder, these also might lend themselves to population-level interventions. ^{Reference Morrison, French, Stewart, Birchwood, Fowler and Gumley8}

Preventive psychiatry research actively seeks out and intervenes in a broader spectrum of states of mind, including carefully defined mental disorders, but extending to the socioculturally constructed illness experience that includes an inextricable link between physical illnesses and emotional factors. Interventions should also promote positive states of health and well-being. Some of the interventions showcased in this issue of the Journal therefore may have value as generic population-based interventions so that patienthood and diagnosis are not the basis of stigma and exclusion, but rather the motivation for research that helps to better understand the mind, and so contribute to wider societal benefits. ⁹