Neuroimaging, immunologic, and pharmacologic studies have emphasized the role of 5-HT2A and 5-HT3A serotonin receptors in the pathophysiology of major depression.
5-HT2A receptor -1438 G/A polymorphism and serotonergic antidepressant-induced sexual dysfunction in male patients with major depressive disorder: a prospective exploratory study.
While further work is needed to identify the actual functional genetic variants involved, these results suggest that a relationship exists between genetic variation in HTR2A and either 5-HTT expression or central serotonergic transmission that influences the therapeutic response to 5-HTT inhibition in major depression.