First-episode schizophrenia — diagnosis, acute management and antipsychotic choice

Diagnosis: first-episode schizophrenia (paranoid/delusional subtype clinically). Continuous disturbance >1 month (DSM-5 core) / typically ≥1 month of psychotic symptoms with 6-month overall disturbance including prodrome (ICD/classic framing), with positive symptoms (third-person auditory hallucinations, thought insertion, persecutory delusions), negative symptoms (blunted affect, avolition, social withdrawal), functional decline, and exclusion of substance/organic causes.^[1][2]

Symptom domains to name:

• Positive: hallucinations, delusions, disorganisation
• Negative: flat affect, alogia, avolition, anhedonia, asociality (the "5 As")
• Cognitive: attention, working memory, executive dysfunction (major driver of disability)

Key differentials (with discriminators):

• Drug-induced psychosis — temporal link to cannabis/stimulants; negative screen here is helpful but not absolute
• Bipolar mania with psychosis — elevated mood, reduced need for sleep, grandiosity, episodic course
• Major depression with psychosis — dominant depressive syndrome with mood-congruent delusions
• Organic — temporal lobe epilepsy, encephalitis (HSV), SLE, neurosyphilis, B12 deficiency, space-occupying lesion — abnormal vitals/neurology/confusion raise concern
• Brief psychotic disorder / schizophreniform — shorter duration thresholds
• Delusional disorder — non-bizarre delusions without prominent hallucinations/disorganisation/negative symptoms

Acute management:

1. Safety and risk — assess suicide (lifetime risk high), violence, self-neglect, exploitation; decide voluntary vs Mental Health Act admission.
2. Medical work-up — FBC, U&E, LFT, glucose/HbA1c, lipids, TFT, B12/folate, urine toxicology; consider CT/MRI if atypical (late onset, focal signs, seizures); HIV/VDRL where relevant.
3. Environment — low-stimulus ward, clear communication, sleep restoration, family engagement.
4. Start an antipsychotic promptly after baseline ECG (QTc), weight, waist, glucose, lipids, prolactin as indicated.^[3]

Antipsychotic plan (first episode):

• Prefer a second-generation antipsychotic at the lowest effective dose, e.g. risperidone 2 mg at night (titrate 2–6 mg/day), olanzapine 5–10 mg at night, aripiprazole 10–15 mg daily, or amisulpride — choose by side-effect profile (metabolic vs EPS vs prolactin vs akathisia).^[3][4]
• Trial duration: adequate dose for 4–6 weeks before declaring non-response.
• Monitor: EPS/akathisia, metabolic syndrome (weight, BMI, glucose, lipids), prolactin (risperidone), sedation, QTc.
• Adjunctive short-term benzodiazepine for severe agitation/insomnia if needed.
• If two adequate antipsychotic failures → consider clozapine (treatment-resistant schizophrenia) with mandatory FBC monitoring.
• Psychosocial: psychoeducation, family intervention, CBT for psychosis, supported education/employment, relapse-prevention plan.
• Maintenance usually ≥1–2 years after first episode (longer if multiple episodes); abrupt stop risks relapse.