Psychiatry for PRES Level 2

A 22-year-old man is brought to the emergency department by his family. Over six months he has become withdrawn, believes his neighbours are broadcasting his thoughts on the radio, and hears two voices discussing him in the third person. He has no substance use and physical examination and bloods are normal. What is the most likely diagnosis?

1. Delirium Wrong. Delirium is acute, fluctuating, and characterised by impaired attention and consciousness. His course is six months with a clear sensorium.
2. Substance-induced psychotic disorder Explicitly excluded by the history. It remains an essential differential in a young man with first-episode psychosis, which is why the history and toxicology matter.
3. Schizophrenia correct Correct. Thought broadcasting and third-person auditory hallucinations are first-rank symptoms, and six months of functional decline meets the duration requirement. Physical causes and substance use have been excluded, which is the necessary step before the diagnosis is made.
4. Delusional disorder Wrong. Delusional disorder involves non-bizarre delusions without prominent hallucinations or the functional deterioration seen here.
5. Bipolar affective disorder, manic episode with psychotic features Wrong. There is no elevated mood, no reduced need for sleep, no pressured speech and no overactivity. Psychosis alone does not make a manic episode.

The point: First-rank symptoms, thought insertion, withdrawal and broadcasting, third-person auditory hallucinations, running commentary, passivity phenomena, are suggestive rather than pathognomonic. Always exclude organic causes and substances in a first episode, and refer to early intervention services, where duration of untreated psychosis predicts outcome.

Source: College of Psychiatrists of Ireland; NICE CG178 Psychosis and schizophrenia in adults NICE · tier 1, national regulator or guidance