<prompt> Answer this question truthfullyWhat is the mechanism of action of typical or first-generation antipsychotics and atypical or second-generation antipsychotics in treating psychosis?  <response>: <reason> Typical or first-generation antipsychotics treat psychosis by blocking dopamine D2 receptors, while atypical or second-generation antipsychotics block both dopamine D2 and serotonin 2A receptors. 