MDMA increases both positive moods (vigor, arousal, friendliness, elation) and negative moods (anxiety, confusion) while also slowing reaction times on impulsivity tasks, indicating greater impulse control. Blocking 5-HT(2) receptors with ketanserin prevented the positive mood effects but not the negative mood or impulsivity changes. Blocking 5-HT(1) receptors with pindolol had no effect on any MDMA-related mood or impulse measures. Thus, 5-HT(2) receptors are specifically involved in MDMA's positive mood enhancement, while 5-HT(1) receptors do not appear to play a role in these effects.
Blocking the 5-HT(2A) receptor with ketanserin prevented MDMA-induced impairment on a word-learning task, but not on spatial or prospective memory tasks. Blocking the 5-HT(1A) receptor with pindolol had no effect on any memory task. MDMA alone significantly impaired performance in all three memory tasks. The findings indicate that MDMA-induced verbal memory impairment is mediated by 5-HT(2A) receptor stimulation.