Synopsis
Recognise psychosis caused or shaped by physical illness, prescribed medicines, intoxication or withdrawal, identify neurological and delirious emergencies, and integrate cause-specific medical treatment with immediate psychiatric safety and follow-up.
- Organic psychosis is a clinical formulation linking psychotic symptoms to brain dysfunction or systemic disease; identify the syndrome and mechanism rather than using the label as an endpoint.
- Substance-induced psychosis requires a precise timeline of dose, route, frequency, potency, last use, sleep, co-exposures, withdrawal and symptom persistence.
- Delirium is suggested by acute onset, impaired attention and fluctuating arousal and remains a medical emergency even when behaviour looks primarily psychiatric.
- Cannabis, stimulants, hallucinogens, steroids, dopaminergic medicines, anticholinergic toxicity and alcohol or sedative withdrawal are important but not exhaustive causes.
- A positive toxicology result shows detected exposure, not causation, dose, impairment or the absence of an independent psychotic disorder.
- Use phenotype-led blood tests, ECG, toxicology, imaging, EEG and cerebrospinal-fluid investigation; normal routine tests cannot exclude encephalitis or epilepsy.
- Treat intoxication, withdrawal, infection, metabolic disturbance or neurological disease while also addressing commands, suicide, violence, vulnerability and dependants.
- Follow the course after medical recovery and supported abstinence because persistent or recurrent symptoms may reveal a primary psychotic or affective disorder.
Key red flags
Impaired attention with fluctuating arousal identifies possible delirium, even when hallucinations, paranoia or agitation dominate the visible presentation.
New seizure, dyskinesia, catatonia, focal deficit, severe headache, neck stiffness or autonomic fluctuation raises encephalitis, epilepsy or structural disease.
Hyperthermia, rigidity, clonus, cardiovascular instability or marked creatine-kinase elevation after medicine or drug exposure may indicate a life-threatening toxic syndrome.
Agitated persecutory behaviour during stimulant intoxication, alcohol withdrawal or hallucinogen use can cause rapid accidental, suicidal or interpersonal harm.
Abrupt psychosis in later life, during pregnancy or after childbirth, or with endocrine or systemic symptoms warrants a widened physical differential.
Investigation priorities
Identify physiological instability, glucose disturbance, injury, impaired attention and fluctuating consciousness.
Management branches
Psychosis coexists with altered arousal, seizure, fever, injury or physiological instability.
- Use ABCDE, glucose, observations and focused neurological examination, summon emergency support and reduce environmental hazards.
- Obtain an exposure timeline, ECG and phenotype-led laboratory, toxicology, imaging, EEG or cerebrospinal-fluid investigation without delaying stabilisation.
- Treat the identified medical or toxic syndrome and provide parallel psychiatric observation, capacity assessment and safeguarding review.