Effects of 3,4-Methylenedioxymethamphetamine on Conditioned Fear Extinction and Retention in a Crossover Study in Healthy Subjects
Frontiers in Pharmacology July 13, 2022 Patrick Vizeli, Isabelle Straumann, Urs Duthaler et al. 43 citations
A single 125 mg dose of MDMA, given to 30 healthy men after fear conditioning and two hours before extinction learning, reduced skin conductance responses to a conditioned fear cue during both extinction learning and its recall the next day, compared with placebo. The drug did not affect fear-potentiated startle responses. Subjective feelings of trust and openness during extinction learning were linked to poorer discrimination between danger and safety cues during recall. MDMA raised oxytocin levels fourfold, but this increase did not correlate with fear extinction outcomes. The findings suggest MDMA can accelerate fear extinction learning and retention, at least for some physiological measures of fear, which may help explain its therapeutic benefit in PTSD.