What neurotransmitters do Tricyclic Antidepressants (TCAs) primarily target?

Tricyclic Antidepressants (TCAs) primarily target serotonin and norepinephrine, which is why this is the correct answer. TCAs work by inhibiting the reuptake of these two neurotransmitters in the brain, leading to increased levels in the synaptic cleft. This action enhances mood and can alleviate symptoms of depression, which is the primary indication for their use.

By blocking the reabsorption of serotonin and norepinephrine, TCAs not only help to improve depressive symptoms but may also have effects on pain pathways, making them effective in treating certain types of chronic pain and anxiety disorders. Their impact on these neurotransmitters differentiates them from other classes of antidepressants, such as SSRIs, which primarily focus on serotonin alone.

The other neurotransmitters mentioned in the options do not play a primary role in the mechanism of action of TCAs. Dopamine, while important in other contexts, is not a direct target for TCAs. Acetylcholine is involved in many functions, including memory and cognition, but it is not the main focus of TCAs. GABA is primarily an inhibitory neurotransmitter but does not have a direct connection to the antidepressant effects of TCAs either.