American Board of Psychiatry and Neurology (ABPN) Practice Exam 2025 - Free ABPN Practice Questions and Study Guide

Aripiprazole is classified as a partial agonist at the dopamine D2 receptor, which means it binds to the receptor and activates it, but to a lesser degree than a full agonist. This unique mechanism of action distinguishes aripiprazole from other antipsychotic medications, which often serve as full antagonists, meaning they block the receptor entirely.

The partial agonist activity of aripiprazole allows it to stabilize dopamine activity in the brain: it can reduce excessive dopamine levels in conditions such as schizophrenia while still providing some dopaminergic activity in areas where dopamine is deficient. This makes aripiprazole particularly useful in treating psychotic disorders, as it can help alleviate symptoms without precipitating the side effects often associated with full dopamine antagonism, such as extrapyramidal symptoms.

This unique pharmacological profile also contributes to some of aripiprazole's applications in treating mood disorders, ADHD, and as an adjunct in depression therapy. This versatility in its clinical application emphasizes the importance of understanding the role of partial agonists in psychopharmacology, setting aripiprazole apart from traditional antipsychotics like haloperidol, olanzapine, and ziprasidone, which