Key Facts

Self-harm and suicide represent a spectrum of self-injurious behaviour. Self-harm is extremely common and is the strongest predictor of future suicide. Every self-harm presentation requires compassionate, thorough assessment.

Epidemiology

Self-harm is the most common reason for acute medical admission in women aged 15-24. Approximately 200,000 hospital attendances annually in England. Suicide rates: ~10 per 100,000 (UK); highest in men aged 45-49. Suicide is the leading cause of death in men under 50 in the UK.

Aetiology

Suicide risk factors:

• Demographic: Male sex, age 45-54 (men), single/divorced, unemployed, social isolation
• Psychiatric: Depression (most common), schizophrenia, bipolar disorder, personality disorder, substance misuse, eating disorders
• Historical: Previous self-harm/attempt (strongest predictor), family history of suicide
• Psychological: Hopelessness (strongest psychological predictor), impulsivity, poor problem-solving
• Social: Recent loss, relationship breakdown, financial crisis, legal problems, bullying
• Clinical: Recent psychiatric discharge (first 3 months), recent diagnosis of serious physical illness

Pathophysiology

• Suicidal behaviour: Complex interaction of predisposing vulnerability, acute stressors, and reduced protective factors
• Serotonergic dysfunction: Reduced CSF 5-HIAA associated with violent suicide attempts
• Psychological models: Cry of Pain model (Williams), Interpersonal Theory of Suicide (Joiner — perceived burdensomeness + thwarted belongingness + acquired capability)
• HPA axis dysregulation: Elevated cortisol, dexamethasone non-suppression associated with suicide risk

Self-Harm Methods

• Self-poisoning/overdose (~80%): Paracetamol (most common), NSAIDs, antidepressants, benzodiazepines
• Self-cutting (~15-20%): Usually forearms, often superficial
• Other: Hanging, burning, ingestion of foreign bodies, head-banging

Assessment of Intent

• Was the act planned or impulsive?
• Were precautions taken against discovery?
• Was a suicide note written?
• Were final acts performed (will, saying goodbye)?
• What was the expected outcome — did they expect to die?
• Was there help-seeking after the act?
• What is the current mental state — ongoing suicidal ideation?

Red Flags for High Suicide Risk

• Stated intent to die
• Planned act with precautions against discovery
• Violent method (hanging, jumping, firearms)
• Male, middle-aged, living alone
• Hopelessness persisting after assessment
• Recent psychiatric discharge
• Command hallucinations to harm self
• Refusing assessment or treatment

Bedside

• Psychosocial assessment: NICE CG16 — by trained professional before discharge
• Risk assessment: Structured professional judgment (not validated checklist alone)
• Mental state examination: Mood, hopelessness, psychosis, intoxication
• Physical assessment: Treat medical consequences of self-harm first

Bloods (for overdose)

• Paracetamol level: At 4 hours post-ingestion — plot on treatment nomogram
• Salicylate level: If mixed overdose suspected
• U&Es, LFTs, clotting (INR): Paracetamol hepatotoxicity
• ECG: If TCA overdose or any cardiotoxic drug
• Blood gas: Salicylate poisoning, TCA overdose

Special Tests

• TOXBASE (National Poisons Information Service): Online resource for poisoning management
• Drug levels: Lithium, digoxin, iron, carbamazepine — as indicated

Non-pharmacological

• Psychosocial assessment before discharge (NICE CG16) — every patient
• Safety planning: Collaborative, personalised safety plan (NOT a 'no-suicide contract')
• Follow-up: Within 48 hours of discharge from emergency department
• Brief interventions: Safety planning intervention, problem-solving therapy
• CBT: For recurrent self-harm; DBT for self-harm in BPD context
• Means restriction counselling: Advise removal of medications, sharp objects from home

Pharmacological

• Paracetamol overdose: N-acetylcysteine (NAC) IV per treatment protocol if level above treatment line
• TCA overdose: Sodium bicarbonate 8.4% 50mL IV for QRS >100ms; avoid flumazenil
• Treat underlying mental illness: Antidepressants (avoid TCAs if suicide risk — prescribe SSRIs), mood stabilisers, antipsychotics as indicated
• Lithium: Reduces suicide risk by ~60% in bipolar disorder
• Clozapine: Reduces suicidality in schizophrenia (InterSePT trial)

Referral Criteria

• All self-harm presentations — psychosocial assessment (A&E liaison psychiatry)
• Ongoing suicidal ideation — crisis team or inpatient admission
• Recurrent self-harm — specialist psychology/psychiatry
• Children and young people — CAMHS urgent assessment

• 1-year repetition rate: ~15-25% after hospital-presenting self-harm
• Lifetime suicide risk: ~3-7% following self-harm presentation
• Highest risk period: First 3-6 months after self-harm episode
• Paracetamol overdose: NAC is ~95% effective if given within 8 hours; mortality <0.5% with timely treatment
• Means restriction: Paracetamol legislation (limiting pack size to 32 tablets) reduced paracetamol-related deaths by ~40%
• Safety planning reduces repeat self-harm by ~50% compared to usual care

SAD PERSONS Score (Mnemonic for Risk Factors)

Paracetamol Overdose Key Facts