A 22-year-old man with a first episode of schizophrenia is started on a second-generation antipsychotic. After three weeks his auditory hallucinations diminish substantially, but he remains socially withdrawn, unmotivated, and emotionally flat. His family asks why these symptoms persist.
Antipsychotics reduce positive symptoms primarily by:
- Acheck_circle
Blocking dopamine D2 receptors in mesolimbic pathways
- B
Stimulating GABA release in the hippocampus
- C
Inhibiting acetylcholine breakdown in cortical synapses
- D
Increasing serotonin reuptake throughout the brain
Explanation
The dopamine hypothesis attributes positive symptoms to mesolimbic dopamine overactivity; antipsychotics antagonize D2 receptors. They do not increase serotonin reuptake, stimulate GABA, or inhibit acetylcholinesterase as their primary mechanism.