Which of the following is an atypical antidepressant?

Cariprazine is classified as an atypical antidepressant because it acts primarily as a partial agonist at dopamine D2 and D3 receptors, along with antagonistic properties at serotonin receptors (5-HT1A). This unique mechanism differentiates it from the more traditional antidepressants, which typically target serotonin or norepinephrine pathways.

Atypical antidepressants often have a diverse pharmacological profile and can also address various aspects of mood disorders that are not fully captured by standard antidepressant medications. Cariprazine's mechanism of action allows it to be effective for treating depression, particularly in patients who may not respond well to conventional antidepressants.

In contrast, fluoxetine and duloxetine belong to the selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) categories, respectively. These drugs predominantly increase serotonin and/or norepinephrine levels in the synaptic cleft, which is characteristic of mainstream antidepressants. Nortriptyline is a tricyclic antidepressant (TCA) that also primarily affects the reuptake of norepinephrine and serotonin but does so in a less targeted manner, often leading to a broader range of side effects.

This distinction highlights car