A randomized placebo-controlled trial tested whether MDMA enhances fear extinction retention in healthy adults. Participants underwent fear conditioning, then received 100 mg MDMA or placebo before extinction training. Fear retention was tested 48 hours later. MDMA was well-tolerated with no serious adverse events. While the overall analysis showed no significant group difference in extinction retention between training and test sessions, a significantly larger proportion of the MDMA group retained extinction learning compared to the placebo group. The results provide a rationale for further research into MDMA's potential effects on fear extinction.
A randomized, placebo-controlled trial with 34 healthy adults examined whether a single dose of MDMA alters five-factor model personality traits and affective states 48 hours later. No statistically significant changes were observed for the four pre-registered hypotheses, but medium effect sizes emerged: trait Openness increased (d = .79) and Positive Affect increased (d = .51) compared to placebo. These preliminary findings suggest MDMA may produce short-term shifts in openness and positive mood, warranting larger, longer-term studies to clarify how such changes might inform MDMA-assisted therapy.