Schizophrenia is a chronic psychiatric disorder characterised by distortions in thinking, perception, emotion, and behaviour. Core features include hallucinations, delusions, disorganised speech or behaviour, and negative symptoms, which together cause major functional impairment.
💡 Lifetime prevalence is around 1%, with onset typically in late adolescence or early adulthood.
Dopamine dysregulation: mesolimbic hyperactivity → positive symptoms; mesocortical hypoactivity → negative symptoms
Structural changes: ventricular enlargement, grey matter loss
Neurodevelopmental disruption: abnormal synaptic pruning, glutamate dysfunction
Risk factors: strong genetic component, plus environmental contributors (urban upbringing, cannabis use, childhood trauma, obstetric complications)
Positive symptoms
Hallucinations (especially auditory)
Delusions (persecutory, grandiose)
Thought disorder
Negative symptoms
Apathy, social withdrawal, poverty of speech, loss of motivation
Cognitive and affective symptoms
Impaired memory and concentration
Depression, anxiety, increased suicide risk
💡 “First-rank symptoms” include thought insertion/withdrawal, auditory commentary voices, and passivity experiences.
Prodromal: subtle withdrawal, reduced functioning, odd behaviour
Active: psychotic symptoms dominate
Residual: fewer positive symptoms, persistent negative features
At least two core symptoms (delusions, hallucinations, disorganised speech/behaviour, negative symptoms) for ≥1 month
Continuous disturbance for ≥6 months
Must cause functional impairment
Exclude mood disorders, substance misuse, or organic causes
Bipolar disorder or schizoaffective disorder
Severe depression with psychosis
Delusional disorder
Substance-induced psychosis
Organic causes: epilepsy, dementia, encephalitis
Bloods: exclude reversible causes, baseline for treatment monitoring
Urine drug screen: rule out substance-related psychosis
ECG: check QTc before antipsychotics
Neuroimaging: only if atypical features or late onset
Psychiatric assessment: mental state exam, risk assessment, collateral history
Antipsychotics: second-generation agents are first-line, choice tailored to side-effect profile and patient preference
Psychological interventions: CBT for psychosis (CBTp), family therapy
Early Intervention in Psychosis (EIP) services: multidisciplinary support in the first years of illness
Hospital admission: may be required if high risk to self or others, or if not managing at home
🚨 Clozapine is reserved for treatment-resistant cases but requires intensive blood monitoring.
