HTR1A and major depressive disorder: Currently, various drugs targeting the HTGPCR family genes, mainly focusing on psychotropic drugs, are used for the treatment of depression, anxiety, schizophrenia, and other conditions, including the selective 5-HT receptor agonists zolmitriptan, 5-HT receptor agonist eletriptan, 5-HT1A receptor agonist buspirone, dopamine receptor agonists cabergoline, and ropinirone, etc. (Figure 9B).