A psychotic disorder with positive symptoms (delusions, hallucinations, disorganisation) and negative symptoms (blunted affect, avolition, alogia) lasting at least 6 months (DSM-5).
How it's asked: Schneider's first-rank symptoms, the dopamine pathways, good prognostic factors, and when to use clozapine.
Why this is true
The dopamine hypothesis explains much of the clinical picture. Excess dopamine activity in the mesolimbic pathway gives positive symptoms, which is why D2-blocking antipsychotics relieve hallucinations and delusions. Reduced activity in the mesocortical pathway to the prefrontal cortex contributes to negative and cognitive symptoms, which respond poorly to D2 blockade. Blocking dopamine elsewhere produces the side effects: in the nigrostriatal pathway (extrapyramidal symptoms) and the tuberoinfundibular pathway (raised prolactin).
Key points
Common traps
- Second-person hallucinations commenting are less specific than third-person 'voices discussing the patient'.
- Negative symptoms predict poorer outcome than positive symptoms.
Clinical case
A 22-year-old believes a chip in his brain lets others read his thoughts and hears two voices discussing him for the past 8 months. His affect is blunted and he has withdrawn from college.
High-yield
First-rank: thought insertion/withdrawal/broadcast, third-person voices, passivity, delusional perception. Mesolimbic ↑DA = positive symptoms. Treatment-resistant → clozapine.
Quick check
Q1.Which is a Schneiderian first-rank symptom?
Q2.Drug of choice in treatment-resistant schizophrenia: