Also know as seritonin deficiency. This is caused by the over use of the seritonin producing cells durnig the E experience. There is evidence that this can become permanent effect if the drug is used to often.

I know this to be true because a person i worked with be depressed all week long and would sometimes have to eat ecstacy during the week just to make it through the day. Its not a pretty sight. Respect your body. Say no.