First-episode schizophrenia — assessment and initial management (MEQ)

(i) Assessment priorities. Structure as risk, medical exclusion, MSE, substance, collateral, capacity and legal status. Risk: suicide (command content, intent, plan, prior attempts, hopelessness), violence, vulnerability, neglect, absconding, cannabis-related impulsivity. Medical exclusion: observations and glucose already reassuring; still take history of fever, seizure, head injury, neurological symptoms; baseline bloods and ECG before antipsychotic; imaging if red flags. MSE with quoted examples of delusion and running commentary hallucination. Cannabis timeline. Collateral from parents on premorbid function and tempo. Capacity for treatment decisions; if incapacitous and risk high, consider involuntary pathway under local statute using least-restrictive principles.[4]

(ii) Working diagnosis and differentials. Working diagnosis: first-episode schizophrenia spectrum / first-episode psychosis evolving toward schizophrenia (continuous disturbance over 4 months with 6 weeks of clear Criterion A symptoms and functional decline). Differentials: substance-induced psychotic disorder (cannabis may contribute but symptoms persist beyond acute intoxication — dual formulation); schizophreniform if total duration still under 6 months at assessment; brief psychotic disorder unlikely given duration; affective psychosis if mood episode is primary (not described as primary here); delirium unlikely with clear sensorium and normal observations; organic causes if atypical features emerge. Discriminators: attention/fluctuation, mood chronology, substance timeline, physical signs.[2]

(iii) Initial management. Engage early intervention / youth psychosis service. Shared decision-making on antipsychotic: e.g. aripiprazole 10 mg orally daily (or risperidone 1–2 mg with titration) after baseline BMI, BP, glucose/HbA1c, lipids, FBC, U&E, LFT, ECG QTc. Trial plan 4–6 weeks at therapeutic dose with adherence support. Side-effect education (akathisia with aripiprazole; metabolic and prolactin risks with alternatives). Psychosocial: family psychoeducation, CBTp access, cannabis cessation counselling, sleep and routine, vocational/education support, crisis plan. Do not combine IM olanzapine with parenteral benzodiazepine if later crisis sedation needed.[1]

(iv) DUP and early intervention. Longer duration of untreated psychosis associates with poorer outcomes across symptom and functional domains — this patient’s months of untreated illness already matter.[2] Early intervention services (OPUS, RAISE-NAVIGATE model) provide multi-element care superior to fragmented treatment as usual on functional and quality-of-life outcomes; care must remain high-quality beyond a short specialised window.[1]

(v) Two failed adequate trials. If two adherent, adequate-dose, adequate-duration antipsychotic trials fail and pseudo-resistance is excluded, he meets TRRIP treatment-resistance principles and should be offered clozapine with full monitoring infrastructure (neutrophils, myocarditis vigilance, bowel care, levels, metabolic monitoring), not endless non-clozapine polypharmacy.[3]