Is there a relationship between serotonin receptor subtypes and selectivity of response in specific psychiatric...

Identification of 5-HT receptor subtypes--5-HT1A, 5-HT1B, 5-HT1C, 5-HT1D, 5-HT2 (possibly A and B), 5-HT3 subtypes, and possibly 5-HT4--has encouraged the manufacture of 5-HT receptor inhibitors with greater subtype specificity. However, it appears that the receptors interact, and drugs initially thought to be specific may have multiple actions. For some conditions such as anxiety/depression, almost all receptors are implicated. Clinical studies provide clear evidence that manipulation of the 5-HT system has a role in treating depression, anxiety, obsessional illness, migraine, and eating disorders. Interactions between the various receptor subtypes make it difficult to identify specific clinical functions. The 5-HT1A receptors may be involved in aggression, anorexia, and hypotension. The 5-HT1B receptors may be involved in aggression, while the 5-HT1C receptors may play a role in central aversion systems and anxiety/depression. The role of the 5-HT1D receptors remains speculative; 5-HT2 receptors appear to be involved in depression, anxiety, appetite, sleep, vasoconstriction, and hypertension. Many drugs that are effective in treating migraine are potent 5-HT2 antagonists. 5-HT3 antagonists at high doses are effective in treating nausea and at low doses in treating anxiety. Treatment of aggression, suicidal behaviour, addiction behaviour, memory impairment, dementia, and schizophrenia with 5-HT inhibitors requires further testing.