EM · Behavioural and mental health emergencies
Mental health and behavioural emergencies
Also known as Psychiatric emergency · Medical clearance of the psychiatric patient · Suicide risk assessment · Acute agitation and rapid tranquillisation · Acute psychosis in the emergency department · Mental Health Act and involuntary detention
Mental health and behavioural emergencies — the medical clearance of the psychiatric patient (excluding the organic cause: hypoglycaemia, hypoxia, sepsis, intracranial lesion, toxidrome, delirium), the structured risk assessment for self-harm, suicide and violence to others, the Mental State Examination, and psychiatric referral. The specific presentations: the suicidal patient (SAD PERSONS, means, plan, intent, safe disposition), the acutely psychotic patient (schizophrenia versus drug-induced; haloperidol 5 mg IM, olanzapine 10 mg PO), and the anxious or agitated patient (de-escalation, lorazepam 1 to 2 mg IV or PO, rapid tranquillisation ladder with droperidol and midazolam). Includes the Mental Health Act framework, involuntary detention, and the four-stage test of capacity. ACEM-primary, globally tagged.
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Related topics
- Consent, capacity and the medico-legal framework in the emergency department
- Breaking bad news and communication in the emergency department — the SPIKES framework
- Acute agitation and rapid tranquillisation
- Deliberate self-harm and suicide risk assessment
- The Mental Health Act and compulsory treatment in the emergency department
- DKA, HHS and hypoglycaemia
- Opioid poisoning and the opioid toxidrome (emergency department diagnosis and management)
Meet the patient
A 28-year-old man with no prior psychiatric history is brought to your department at two in the morning by his flatmate after two weeks of progressive social withdrawal, paranoid beliefs that his food is being poisoned, and three days of auditory hallucinations. He is dishevelled, guarded, smells of cannabis, refuses to let you examine him, and is intermittently internally preoccupied. His observations show a mild fever and tachycardia. The bedside glucose is 5.6. The flatmate says this is nothing like the man he knows.[1]
The two questions that decide his next two hours are the two that decide every behavioural emergency: is there an organic cause driving this? (the medical screen answers that) and what is the immediate risk? (the structured risk assessment answers that). Reach for the sedative or sign the schedule before the glucose and the observations are done and you have failed at the first step.[1]
You have read the opening of this topic. The complete unit — every section and its primary-source references — is part of the Emergency Medicine fellowship atlas.
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- [1]Ünlü L, Griese JA, Minotti B, et al. Medical Screening of Adult Psychiatric Patients Presenting to the Emergency Department Ann Emerg Med, 2026.PMID 42233919
- [2]Sanz-Gómez S, et al. Predictive validity of the SAD PERSONS and NO HOPE scales in a sample of suicide cases Front Psychol, 2025.PMID 40342345
- [3]Uribe ES, et al. Pharmacological management of acute agitation in psychiatric patients: an umbrella review BMC Psychiatry, 2025.PMID 40133850
- [4]Cole JB, DeVries PA, O'Flaherty JL, et al. Intramuscular droperidol, olanzapine, midazolam, or lorazepam to treat methamphetamine intoxication in the emergency department Am J Emerg Med, 2026.PMID 41740194