Evaluation of 3,4-methylenedioxymethamphetamine (MDMA) on Startle Response
This randomized, blinded, placebo-controlled Phase 1 mechanism of action study investigated the effects of MDMA on startle testing learning in healthy volunteers in comparison to a placebo control.
This study enrolled healthy participants. All participants underwent a 1-hour startle test where acoustic startle was measured through assessing eye-blink response from the orbicularis oculi muscles in response to a 106 dB noise, using sensors under the eye. While watching the computer monitor, the participants also experienced several brief blasts of air directed at the throat. The next day, participants were randomized to receive 100 mg of MDMA or inactive placebo, after which they underwent another startle task. Blood was drawn before and after drug administration to measure levels of oxytocin and other hormones or proteins, such as cortisol or brain-derived neurotrophic factor (BDNF). Participants returned for a third visit which included another startle test and recall task. Sleep was also measured via self-report and Fittbit.