What is the primary mechanism of action of drugs that treat psychosis?

The primary mechanism of action for drugs that treat psychosis, particularly antipsychotics, revolves around blocking dopamine binding to D2 receptors. This is based on the dopamine hypothesis of psychosis, which posits that an overactivity of dopamine transmission, especially within certain brain pathways, is linked to the symptoms of psychotic disorders such as schizophrenia.

By antagonizing D2 receptors, these medications reduce dopaminergic signaling, which is believed to alleviate psychotic symptoms like hallucinations and delusions. This blockade primarily occurs in key brain areas involved in emotion and cognition, thus providing the therapeutic effects observed with antipsychotic treatment.

While other options do involve important neurotransmitter systems, they are less central to the primary action seen with antipsychotics. For example, blocking serotonin receptors can be a part of the mechanism in some atypical antipsychotics but is not the core action for treating psychosis overall. Inhibiting norepinephrine reuptake and enhancing GABA activity are mechanisms associated with different psychiatric conditions and treatments and do not directly address the underlying dopaminergic dysregulation associated with psychosis.