6 General adult psychiatry6.4 Emergency psychiatry
6.4.1 Suicide, attempted suicide and self harm
8 min read3 figures
Written by Resident Doctor Committee · Published
Terms
Self-harm is intentional self-poisoning or self-injury, whatever its apparent purpose. Intent is assessed separately, and the older term parasuicide can blur this.
Suicidal ideation ranges from a passive death wish to detailed plans.
Intent is how far someone means to act.
A suicide attempt involves at least some intent to die.
Death by suicide is a fatal act undertaken with suicidal intent.
Physical severity does not reliably show intent: a small overdose may follow determined planning. Repetitive self-injury may regulate distress but does not protect against a later fatal act.
Epidemiology of suicide
Suicide causes roughly 1% of all deaths worldwide each year.
Official statistics undercount, because classification depends on coroner practice and on cultural, religious and legal attitudes.
About three-quarters of UK suicides are male (about 3:1).
The male excess holds almost everywhere. China was the recognised exception before the mid-2000s, with a female excess driven by young rural women taking pesticides.
Suicide is a leading cause of death in young people.
In England and Wales in 2024 the age-standardised rate was 11.4 per 100,000 (men 17.6, women 5.7), highest in men aged 50 to 54 at 27.5.
Epidemiology of self-harm and suicidal behaviour
Self-harm and attempted suicide are commoner in women, with the highest rates in girls aged 15 to 19.
Lifetime self-harm among adults in England is about 10% (10.3% of those aged 16 to 74, Adult Psychiatric Morbidity Survey 2023/4), and many are unknown to services.
About 60% of transitions from suicidal ideation to a plan or attempt happen within 12 months of ideation onset (World Mental Health surveys).
The 2000 Office for National Statistics survey of adults in private households found these rates:
Measure | Prevalence |
|---|---|
Lifetime suicidal thoughts | About 15% |
Lifetime suicide attempt | About 4% |
Lifetime self-harm without suicidal intent | About 2% |
Suicide attempt in the previous 12 months | About 0.5% |
Group | Finding |
|---|---|
Recipients of Employment and Support Allowance | Highest lifetime suicide attempt rate in the 2014 survey: 43.2%, against about 7% of all adults |
Schizophrenia spectrum disorder | About 31% have ever self-harmed (Lorentzen and colleagues, 2022) |
Young people identifying as goth | About half have self-harmed |
Prisoners, asylum seekers, armed forces veterans, people bereaved by suicide | Raised incidence of self-harm |
Some cultural and sexual minorities, including lesbian, gay and bisexual people | Raised incidence of self-harm |
Methods
Hanging, strangulation and suffocation is the commonest method in England and Wales and among people in contact with mental health services, where it accounts for about half of suicides.
Self-poisoning comes second at about a fifth, including in women. It is a much larger share of female than male suicides, while men more often use violent methods.
The dominant method follows locally available lethal means: firearms in the United States, pesticides in rural Asia, hanging in England. This is why means restriction works.
Firearm suicide is uncommon in the UK, and the usual victim is a rural man with lawful access, such as a farmer.
Veterinary surgeons die by suicide at 3 to 4 times the population rate, usually by self-poisoning with drugs from work such as pentobarbital.
In prison, suicide risk peaks in the first days of custody and is higher on remand; most self-inflicted deaths are by ligature.
Repeated self-cutting is commonest in adolescents and young women.
Risk factors for suicide
A previous suicide attempt is the single strongest known predictor of eventual suicide, and previous self-harm is the strongest single predictor among people who self-harm.
About half of people who die by suicide have self-harmed before.
Psychiatric and psychological
Any diagnosed mental disorder raises suicide risk about eight-fold (Too et al., 2019, record-linkage meta-analysis).
Psychological autopsy studies find a mental disorder in about 90% of suicides, a higher figure than record-linkage estimates, most often mood disorder or substance misuse.
The commonest diagnosis in suicide is unipolar depression, then substance use disorders, then bipolar disorder and schizophrenia.
The lifetime risk of suicide in schizophrenia is usually quoted as 5 to 15%.
The link with dementia is uncertain, any excess falling soon after diagnosis, whereas other major disorders show a consistent rise.
Hopelessness on the Beck Hopelessness Scale predicted later suicide in Beck's ten-year follow-up of patients with suicidal ideation, whereas depression scores did not.
Physical
Chronic painful physical illness raises suicide risk.
Traumatic brain injury raises later suicide risk more, and more reliably, than other common physical conditions.
Social
Sociodemographic risk factors accumulate, and protective factors offset them.
Risk factor | Protective counterpart |
|---|---|
Male sex | Female sex |
Divorce, separation or loss of a partner | Marriage |
Unemployment | Employment |
Living alone, social isolation | Living with family |
Middle age, low socio-economic position | None listed |
Unemployment roughly doubles or triples the suicide rate, raises self-harm too, and is tied to recessions, debt and lost income.
Antidepressants
Antidepressant-associated suicidality is a small excess of non-fatal suicidal ideation or behaviour under age 25, with no excess from 25 upwards and no rise in completed suicide.
Lofepramine carries the lowest overdose risk among tricyclics, so the National Institute for Health and Care Excellence (NICE) exempts it from the class warning.
Contact with services before suicide
The annual suicide rate among people in contact with mental health services in England is about 100 per 100,000 (1 in 1,000), against about 10 per 100,000 overall (National Confidential Inquiry into Suicide and Safety in Mental Health).
The same inquiry estimates that roughly a quarter of suicides by mental health patients could have been prevented.
Only about a quarter of people who die by suicide have been in contact with specialist mental health services.
Primary care contact rises as death approaches: about 45% saw primary care in the final month and about 1 in 5 in the final week.
About half of people attending the emergency department after self-harm saw their general practitioner in the preceding month.
Outcomes after self-harm
Outcome | Rate |
|---|---|
Repeat non-fatal self-harm | About 1 in 6 (15 to 16%) within a year, highest in the first weeks |
Suicide in 1 to 2 years | About 1% (0.5 to 2%), 50 to 100 times the population rate, concentrated in the first weeks and months |
Suicide over ten years or more | At least 3%, about 5% |
Repetition is predicted by previous self-harm, psychiatric treatment, personality disorder and alcohol or drug misuse, not by demographic features or one-off events.
Even a single episode in a young person raises their risk of eventual suicide.
In older adults, self-harm is rarer but more lethal per episode, carries higher intent and is more often a failed suicide attempt, so every episode needs a full psychosocial assessment.
Most people do not die by suicide after self-harm, and population associations do not predict an individual's outcome.
Assessment
Offer a non-judgemental psychosocial assessment alongside physical treatment; do not wait for physical treatment to finish or use an alcohol level as a threshold.
Explore the act: planning, expected lethality, precautions against discovery, preparations, how the person feels about surviving and whether intent persists.
Asking directly about suicide does not create suicidal intent.
Assess mental state, substances, decision-specific capacity, safeguarding, support, collateral history, and dependants or others at risk.
Formulation, not prediction
Do not use risk scales or global low, medium or high labels to predict suicide, choose treatment or decide discharge.
Low event rates wreck prediction: in 10,000 people after self-harm with 0.5% dying within a year, a test with 80% sensitivity and 80% specificity flags 2,030, of whom 40 die.
The positive predictive value is therefore 40 / 2,030, about 2%, and 10 deaths occur among those not flagged.
Factor | What it does | Examples |
|---|---|---|
Predisposing | Present before the crisis | Early adversity, chronic illness or pain, personal or family history of self-harm or suicide |
Precipitating | Brings the crisis to a head | Loss, conflict, financial or legal crisis, escalating substance use |
Perpetuating | Keeps risk raised | Access to means, untreated illness, isolation, shame |
Protective | Reduces risk but can weaken in crisis | Relationships, responsibilities, beliefs, reasons for living |
Protective factors never simply cancel out risks.
Management and aftercare
Use the least restrictive observation that meets current safety needs.
A written safety plan covers warning signs, coping strategies, safe people and places, contacts, crisis services and means restriction.
No-suicide contracts lack evidence of benefit and do not replace assessment.
A capacitous adult's refusal of disclosure is usually respected where only they are at risk; disclosure may be lawful to protect others or for someone lacking capacity.
NICE NG225 recommends a cognitive behavioural therapy (CBT)-informed psychological intervention of about 4 to 10 sessions for adults after self-harm.
Do not prescribe medication specifically to prevent self-harm; treat any underlying disorder.
Where safety concerns continue, NICE recommends initial aftercare within 48 hours of the psychosocial assessment.
Repeated self-harm needs a consistent collaborative plan, not punitive or dismissive responses.
Postvention supports relatives, friends and staff after a suicide; bereaved people may need assessment for depression, prolonged grief and suicidality.
Prevention
Population-based (universal) measures reach everyone regardless of risk, such as guidelines for responsible media reporting; targeted measures address high-risk groups or individuals.
Removing ligature points from wards is credited with most of the fall in UK inpatient suicide since the early 2000s.
Self-poisoning
Paracetamol, alone or in compound products, is the drug most often taken in overdose in the UK.
Its hepatotoxicity comes from NAPQI, a reactive oxidative metabolite.
A plasma paracetamol level is interpretable only from 4 hours after a single ingestion.
Blind acetylcysteine is unnecessary when a 4-hour result will be available within 8 hours of ingestion.
A reported overdose must be investigated whatever the patient's psychiatric diagnosis.
A non-severe anaphylactoid reaction to intravenous acetylcysteine is not true allergy: pause the infusion, give an antihistamine and restart more slowly.
Flumazenil has no UK licence for benzodiazepine overdose, so its use is off-label.
Flumazenil lowers the seizure threshold, so it is avoided in suspected benzodiazepine overdose in epilepsy.