Pharmacologic mechanisms of action of antidepressants

In addition to standard types of antidepressants such as the TCAs and MAOIs, there are now newer drugs that have chemical structures and pharmacologic properties quite distinct from those of the original antidepressants. The various classes of antidepressants do have some properties in common, though, particularly an ability to down-regulate central beta-adrenergic receptors after their repeated administration. However, whether all types of antidepressants act through the same mechanism is not known.