PwnX
Bluelighter
They cause massive downregulation across all types of 5-HT receptor I think, but certain types more than others, which is what gives SSRIs their characteristic effects. Other indirect effects include less dopamine release (which could explain the anxiolysis in some people, and anxiogenesis in others, as both high and low dopamine can cause anxiety) and also less oxytocin release (high oxytocin is linked to the social effects of MDMA, so whichever 5-HT receptors are responsible for oxytocin release are probably the ones worst affected by downregulation, possibly explaining some of the SSRI zombie effect).
