Which neurotransmitter is least likely to be targeted by antidepressant medications?

• A. Acetylcholine
• B. Dopamine
• C. Serotonin
• D. Norepinephrine

Answer: (A)

Antidepressants mainly work by boosting monoamine signaling involved in mood, especially serotonin and norepinephrine, with some agents also affecting dopamine. Serotonin reuptake inhibitors increase serotonin levels in the synapse, SNRIs raise both serotonin and norepinephrine, and certain drugs influence dopamine pathways. Acetylcholine isn’t a primary target for treating depression; while anticholinergic effects can appear with some antidepressants, they reflect side effects rather than the therapeutic mechanism. So acetylcholine is the least likely neurotransmitter to be directly targeted by antidepressant medications.