A 21-year-old man has auditory hallucinations and persecutory delusions for 3 weeks. He was previously well, is functioning normally at university, and urine drug screen is negative.
Diagnosis?
Answer: Brief psychotic disorder
Logic: Psychosis < 1 month and no functional decline. If it persists beyond 1 month, the diagnosis would change to Schizophreniform.
A 26-year-old woman has social withdrawal for 8 months. For the last 5 weeks she hears voices conversing. She stopped working and neglects self-care. No mood symptoms, no substance use.
Diagnosis?
Answer: Schizophrenia
Logic: Total duration of illness > 6 months (prodromal social withdrawal + active psychosis) + marked functional decline + no mood or substance exclusions.
A 30-year-old man presents with grandiose delusions, pressured speech, flight of ideas, reduced sleep, and elevated mood for 10 days. Hallucinations present only during mood elevation.
Diagnosis?
Answer: Bipolar disorder with psychotic features (Manic Episode)
Logic: Psychosis is mood-congruent (grandiosity) and occurs exclusively during the mood episode. If psychosis occurred for 2 weeks in the absence of a mood episode, it would be Schizoaffective.
A 24-year-old woman has flat affect, alogia, avolition, and social withdrawal for 1 year. No hallucinations, no delusions, no thought disorder.
Diagnosis?
Answer: Not Schizophrenia
Logic: Gate A not met. Negative symptoms alone (Avolition, Alogia, Flat affect) are insufficient for a diagnosis of Schizophrenia without at least one ‘positive’ symptom (delusions, hallucinations, or disorganized speech).
A 58-year-old man presents with visual hallucinations, fluctuating attention, agitation, and fever. Symptoms began 2 days ago.
Diagnosis?
Answer: Delirium (Organic Psychosis)
Logic: Acute onset + visual hallucinations (more common in organic cases) + fluctuating levels of consciousness/attention + fever (suggests medical cause).
