Which of the following medications is an example of a commonly prescribed antidepressant?

Citalopram is a selective serotonin reuptake inhibitor (SSRI) that is widely prescribed for the treatment of depression and anxiety disorders. SSRIs work by increasing the levels of serotonin in the brain, which can help improve mood and alleviate symptoms of depression. Due to its efficacy and relatively favorable side effect profile, Citalopram is often one of the first-line medications prescribed for patients exhibiting signs of depressive disorders.

The other medications listed serve different primary purposes. Gabapentin is primarily used as an anticonvulsant and for nerve pain management, making it beneficial for conditions like epilepsy and neuropathic pain but not for treating depression. Metformin is an oral medication used to manage blood sugar levels in patients with type 2 diabetes, and does not have a role in treating mood disorders. Amlodipine is a calcium channel blocker used to manage hypertension and certain heart conditions, which has no application in the treatment of depression.

Recognizing Citalopram as a commonly prescribed antidepressant among these options illustrates the importance of understanding medication classifications and their proper uses in clinical settings.