Mental Health Prevention

What prevention means, and what it does not cover

Mental health is a state of well-being that helps people cope with life's stresses, work well and contribute to their community, and it sits on a continuum that each person experiences differently.¹ A person's position on it is not fixed, which leaves scope to protect it, and to act early when it falls.

The word has a narrower technical meaning than everyday use suggests. In the framework that governs the research literature, a preventive intervention is one delivered before a person meets the diagnostic criteria for a disorder.

Interventions for people who do meet them are treatment. The long-term care of people whose illness has not remitted is maintenance.⁶ That boundary makes it possible to say whether prevention worked at all.

Not every difficulty can be prevented. Many can be, with the right approach.² Others can be eased with support at the right time.

The two schemes, and why only one is current

Prevention comes with two sets of terms, often printed side by side as though they were parallel ways of describing the same thing. They are not. One replaced part of the other.

The 1994 Institute of Medicine committee proposed universal, selective and indicated as subdivisions of what had until then been called primary prevention. They formed part of a wider scheme of prevention, treatment and maintenance, and the 2009 report kept that categorisation.⁶³ The three current terms are distinguished from one another purely by the population they target.

On the IOM definition, tertiary prevention is not prevention: the person already has the disorder that prevention was meant to stop.

Keeping the older word makes prevention sound as though it covers the whole of mental health care, and a term that covers everything cannot show what worked.

A fourth category has since been added alongside the three. Mental health promotion aims to strengthen a person's ability to meet age-appropriate developmental tasks, and it also aims at a sense of mastery and well-being, and at coping with adversity. Enough evidence has accumulated for it to count as a major category of preventive intervention in its own right.⁶

What prevention has actually achieved

The strongest results come from adolescent depression, where the risk factors are well characterised and the trials have been replicated. Clarke and colleagues adapted a group cognitive behavioural course for adolescents who had a depressed parent and who already had subsyndromal symptoms themselves, a group at raised risk on both counts.⁶ Subsyndromal means symptoms are present but below the level a diagnosis requires.

Of the adolescents who received the course, 9.3% went on to develop a major depressive disorder, against 28% of adolescents at similar risk who did not receive it.⁶ Garber and colleagues then replicated the study across four sites. At a 33-month follow-up they found significantly fewer onsets of depressive episodes in the intervention group.

Effects of that size are not confined to depression. The New Beginnings Program worked with families facing divorce; its results were still visible fifteen years later.

The young adults who had received it were less likely to develop an internalising disorder than controls, and the men among them showed lower rates of substance-related disorder.⁶ Internalising disorders are the ones whose symptoms show as distress inside the person rather than as outward behaviour. These were courses of roughly a dozen sessions, delivered to families under a specific, identifiable stressor.

Where it stopped working

The four-site replication also found a limit. Among the adolescents whose parents were currently depressed at the time of enrolment, the average rate of onset did not differ statistically between the intervention and comparison groups.⁶

A programme aimed at the young person did not overcome an active depressive episode in the parent living in the same house. Prevention delivered to one member of a family is not reliable while another member's illness goes untreated. Treating the parent is part of preventing the child.

Universal programmes and who actually benefits

The Good Behavior Game is a classroom intervention, delivered to whole first and second grade classes, and aims at teachers' classroom management and at reducing aggressive and disruptive behaviour.

It was tested in a randomised controlled trial across 40 first grade classrooms in 18 elementary schools in Baltimore.⁶ In such a trial, who receives the intervention is settled by chance rather than by choice. It is universal by design, so every child in the room receives it, whatever their level of risk.

The benefit was not spread evenly, and children at the highest level of risk benefited more than those at lower risk. The most aggressive boys in first grade showed the greatest reduction in aggressive behaviour, through to grade seven. Those boys were less likely to develop antisocial personality disorder as adults, and showed a 50% reduction in lifetime illicit drug use.⁶

A universal programme can therefore do most of its work through a minority. That is an argument for delivering it universally, not against it. No child had to be singled out, assessed or referred for those at highest risk to receive it, whereas selective and indicated programmes cannot avoid doing exactly that.

What has evidence, and what does not

The well-evidenced part of prevention is narrow. For adolescent substance use, the most recent Cochrane review found only three interventions with sufficient evidence to be judged efficacious or effective: the Unplugged programme, Life Skills Training and the Good Behavior Game.⁶

All three are universal and school-based, adopted school-wide and delivered in the classroom by teachers trained in them. The review did not identify selective or indicated programmes meeting the same standard.⁶

A great deal of prevention activity has no evidence of that grade. A programme whose logic sounds sensible has not necessarily been shown to work.

Risk and protective factors

Prevention works by reducing risk and strengthening protection. In prevention research a risk factor has to predate the onset of the illness. The factors worth targeting are those that are both causal and changeable. Well-studied examples include having a parent with mental illness, and severe loss such as the death of a family member.⁶

Protective factors work the other way. Most are non-specific, meaning they lower risk across many conditions rather than one. Commonly cited examples are a supportive family environment, adequate family financial resources and access to high-quality education.⁶

WHO adds social and emotional skills, decent work, safe neighbourhoods and strong community ties.¹ You can read more about protective factors and how they work.

Much of this concentrates in adolescence, because that is when much of it begins. About one in seven adolescents aged 10 to 19 live with a mental health condition, and many go unrecognised.⁴ Exposure to poverty, abuse or violence raises vulnerability. Supportive environments in the family, at school and in the wider community protect against it.

Why clinicians find this hard

Prevention asks a different question from treatment. The psychiatric literature states plainly that many clinicians have been slow to take it up.⁶ Treatment asks what can be done for the person in front of you now. Prevention asks what the child, the family and sometimes the wider community will need in one, three and five years, so that development stays healthy.

That is not a natural question for a profession organised around presenting problems. Accepting it requires what the textbook calls a major paradigm shift: a move away from concentrating on the diagnosis and treatment of those already seriously ill.⁶ It is named there as one reason preventive intervention has been adopted slowly in practice.

What follows for you

Most of what is proven in prevention is delivered by programmes, not chosen by individuals. Trial results of this kind do not convert into personal advice. The interventions above ran as structured courses of roughly eight to twelve sessions, delivered to defined groups, usually with a parent involved.⁶

If you live with depression and have children at home, treating your own episode is among the better-evidenced things you can do for them.

An active parental episode is exactly where the child-focused programmes stopped working. If a young person is showing early symptoms rather than none, that is where indicated programmes have produced their strongest results.⁶

The everyday measures are worth keeping in proportion. Sleep, activity, staying in contact with people you trust and asking for help early are sensible, and they also cost little. At a population level, tackling inequality and the social and economic conditions that affect mental health matters as much as individual effort.²

None of that carries the same grade of evidence as the trials described above. A habit is not a proven intervention, and it should not be presented as though it were.

If you want to talk something through, or act early on a concern, a therapist can help. Our guide on how to find the right therapist covers what to look for and how to begin. WHO treats this as a global priority. Its Comprehensive Mental Health Action Plan 2013 to 2030 commits countries to strategies for promotion and prevention.⁵

Frequently asked questions

Is prevention the same as treatment?

No. A preventive intervention is delivered before a person meets diagnostic criteria.

Once they do, it is treatment, and long-term care for an illness that has not remitted is maintenance.⁶ The boundary is what allows a trial to report whether onset was prevented.

Can every mental health problem be prevented?

No. In the best-replicated adolescent trials the intervention cut onset of major depression to 9.3% in a high-risk group, against 28% in the comparison group.⁶ That is a substantial result, though it still leaves nearly one adolescent in ten developing the disorder, despite receiving a programme that worked.

If a parent has depression, does prevention still work for the child?

It works, with one documented exception that matters. Where the parent was currently depressed at the point of enrolment, onset rates in the intervention and comparison groups did not differ statistically.⁶ Getting treatment for the parent's current episode is part of the prevention.

Is prevention only for children?

No, though that is where the evidence is deepest. The major mental illnesses of adulthood have their onsets in childhood and adolescence, and symptoms usually precede the full disorder by several years.⁶ Prevention applies across the whole of life; the settings change and the aim does not.

This article is for general information and is not a substitute for professional assessment or care. If your mental health, or that of someone you care about, is affecting daily life, consider speaking with a qualified mental health professional.

References

1. [1] World Health Organization (2022). Mental health: strengthening our response (fact sheet). Describes mental health as a state of well-being enabling people to cope with the stresses of life, work well and contribute to their community; sets it on a continuum experienced differently by each person; and lists protective factors including social and emotional skills, quality education, decent work, safe neighbourhoods and community cohesion. who.int.
2. [2] Mental Health Foundation (2021). Prevention and mental health. Sets out the primary, secondary and tertiary framing of prevention, states that many mental health problems can be prevented with the right approach, and argues that tackling inequalities and the social and economic factors that affect mental health is part of prevention. mentalhealth.org.uk.
3. [3] National Research Council and Institute of Medicine (2009). Defining the Scope of Prevention, in Preventing Mental, Emotional, and Behavioral Disorders Among Young People. The report retaining and elaborating the universal, selective and indicated categorisation first set out by the 1994 IOM committee. ncbi.nlm.nih.gov/books/NBK32789.
4. [4] World Health Organization (2025). Mental health of adolescents (fact sheet). States that one in seven 10 to 19 year olds experiences a mental disorder, that these largely go unrecognised and untreated, that exposure to poverty, abuse or violence increases vulnerability, and that supportive environments in the family, at school and in the wider community are protective. who.int.
5. [5] World Health Organization. Comprehensive Mental Health Action Plan 2013-2030. Commits member states to strategies for mental health promotion and the prevention of mental disorders. who.int/publications/i/item/9789240031029.
6. [6] Sadock, B. J., Sadock, V. A., & Ruiz, P. (Eds.). (2017). Kaplan & Sadock's Comprehensive Textbook of Psychiatry (10th ed.). Section 55.9, Prevention of Psychiatric Disorders in Children and Adolescents, records that the 1994 IOM Committee on the Prevention of Mental Disorders recommended an alternative definitional taxonomy of prevention, treatment and maintenance, restricting "preventive intervention" to interventions provided prior to a patient receiving a psychiatric diagnosis, reserving "treatment" for those with a diagnosis and "maintenance" for the care of patients with chronic illnesses who had not remitted; that preventive interventions previously referred to as primary prevention were subdivided into universal, selective and indicated categories differentiated by their targeted populations, a categorisation continued in the 2009 report; that universal interventions are targeted to the general public or a specified group and provided to individuals at all levels of risk including none, selective interventions to individuals whose risk has been demonstrated to be increased, and indicated interventions to high-risk individuals with detectable signs or symptoms; that mental health promotion has accumulated sufficient evidence to be included as a fourth major category; that a risk factor in prevention must predate onset and that reduction of risk factors both causal and malleable is the goal, with parental mental illness and severe loss as well-studied examples; that protective factors are mostly non-specific, commonly including a supportive family environment, adequate family financial resources and access to high-quality education; that in the New Beginnings Program for families facing divorce a 15-year follow-up showed young adults who received the intervention were less likely to develop an internalizing disorder and that males showed lower rates of substance-related disorders; that in the Good Behavior Game, a universal classroom intervention tested in a randomised controlled trial across 40 first grade classrooms in 18 elementary schools in Baltimore, children at the highest level of risk benefited more than lower-risk children, and the most aggressive first grade boys showed the greatest reduction in aggressive behaviour through seventh grade, were less likely to develop antisocial personality disorder as adults and had a 50 percent reduction in lifetime illicit drug use; that in Clarke and colleagues' Coping with Depression course delivered to adolescents of depressed parents with subsyndromal symptoms, only 9.3 percent went on to develop a major depressive disorder compared to 28 percent of adolescents at similar risk who did not receive the intervention; that Garber and colleagues' four-site replication found significantly fewer onsets at 33-month follow-up but that for adolescents whose parents were currently depressed at the time of enrollment the average rate of onset did not differ statistically between intervention and nonintervention groups; that the TIPS Early Detection study in Norway and Denmark shortened the duration of untreated psychosis by an average of 1.5 years; that prevention requires a major paradigm shift from a traditional concentration on the diagnosis and treatment of those seriously ill and asks instead what the child, family and broader community need 1, 3 and 5 years down the line, with many psychiatrists reluctant to embrace preventive intervention; and that the major mental illnesses of adulthood have their onsets in childhood and adolescence, with symptom onset preceding full disorder in most cases by several years. Section 55.5, Adolescent Substance Use Disorders, records that according to the most recent Cochrane review only three interventions had sufficient evidence to be deemed efficacious or effective, namely the Unplugged Program, Life Skills Training and the Good Behavior Game, all universal school-based interventions adopted school-wide and delivered by trained teachers in the classroom, and that the review did not identify selective interventions meeting that bar.