Partial agonist at D2, D3; high affinity for 5-HT1A describes which agent?

• A. Aripiprazole
• B. Brexpiprazole
• C. Quetiapine
• D. Cariprazine

Answer: (D)

Dopamine receptor partial agonism across D2 and D3, with a notable preference for D3 and activity at 5-HT1A receptors, defines the agent described. Cariprazine fits this profile best because it is a dopamine D3-preferring partial agonist at D2 as well, providing functional modulation of dopamine signaling through both subtypes but with greater influence on D3 receptors. It also has high affinity as a 5-HT1A partial agonist, contributing to anxiolytic and antidepressant-like effects. The other antipsychotics described either lack strong D3 activity (or have less D3 selectivity), or are not primarily partial agonists at dopamine receptors (as with quetiapine, which is mainly antagonistic). Hence, cariprazine is the agent described.