Can we predict response to antidepressants?

There is a large body of evidence supporting the idea that the serotonin neurotransmitter system is abnormal in patients with major depression.6 Serotonin (5-HT) acts on at least 15 different receptors and is cleared from synapses primarily by the serotonin transporter. One of these, the 5-HT1A receptor, is located on serotonin-producing neurons (in the dorsal raphe nucleus), where it provides negative feedback to communicate to these cells when to reduce the release of serotonin (Figure 1).