MDMA enhances positive affective responses to social feedback

Bershad and colleagues frame social feedback processing as fundamental to functioning and note that many psychiatric disorders involve either exaggerated responses to negative social input or blunted responses to positive social input. Prior human and preclinical studies indicate that MDMA produces prosocial effects—enhancing feelings of closeness, sociability, and positive reactivity to social cues—and has shown promise as an adjunct to psychotherapy, possibly by improving therapeutic alliance. However, studies to date have mainly used simple, standardised social stimuli (for example, static emotional faces or simulated exclusion using Cyberball), and it remains unclear whether MDMA alters affective responses to overt, personalised social acceptance and rejection. The present study set out to test whether MDMA modifies emotional responses to explicit social feedback. Specifically, the investigators compared two doses of MDMA (0.75 mg/kg and 1.5 mg/kg) with placebo and with an active stimulant comparator, methamphetamine (MA, 20 mg), using a personalised Social Feedback Task that simulates a dating-app style acceptance/rejection interaction. The primary hypotheses were that MDMA would both enhance positive affective responses to acceptance and reduce negative affective responses to rejection.

This was a double-blind, placebo-controlled, within-subject crossover trial in healthy volunteers (N = 36; 18 women, 18 men), ages 18–40, all with some prior MDMA exposure (4–40 uses). Participants were screened with medical and psychiatric assessments including an in-person psychiatric interview, ECG, and drug-use history. Key exclusions included current psychiatric diagnoses (including major depressive disorder), serious medical conditions, cardiac or liver disease history, current or past substance abuse, contraindicated medications, pregnancy/lactation, and prior negative reaction to MDMA. Inclusion criteria included English fluency, at least high-school education, and BMI 19–30 kg/m2. Each participant completed four laboratory sessions (placebo, 0.75 mg/kg MDMA, 1.5 mg/kg MDMA, and 20 mg MA) in randomised order, separated by at least 72 hours. Sessions ran from 09:00 to 13:30. Drugs were encapsulated with lactose filler; placebo contained lactose only. Participants completed baseline mood and cardiovascular measures, ingested the capsule at 09:30, and were monitored at multiple time points. Subjective and cardiovascular measures were collected throughout; portable monitors measured heart rate and blood pressure at five time points (reported as -15, 30, 60, 180, and 240 minutes post-drug). Mean arterial pressure (MAP) was calculated using the standard formula MAP = (systolic BP + 2 × diastolic BP)/3. The key behavioural measure was the Social Feedback Task. During an orientation visit participants created a personal profile (biographical details, interests, photo) and selected preferred-sex profiles (from 500) they rated as most likely to form a mutual connection. During each drug session, at expected peak drug effect, participants were shown their highest-rated profiles and received feedback indicating the other person either liked them (acceptance), did not like them (rejection), or had not completed ratings (neutral). Trials were organised into blocks (12 trials per block; varied intensities of acceptance/rejection). After each trial participants rated, on five-point Likert scales, how sad, rejected, happy, and accepted they felt. Separate sets of profiles were used for each session to avoid repetition. Subjective drug effects were assessed using the Drug Effects Questionnaire (visual analogue-style items: felt drug, liked/disliked effect, felt high, would want more) and an End of Session Questionnaire asking participants what drug they believed they had received and whether they would take it again. Analyses used repeated-measures ANOVA with dose and condition (accept/reject/neutral) as within-subject factors; significant main effects and interactions were followed by post hoc t-tests. For measures collected at multiple time points, peak change from baseline was used in analysis. Missing data were deleted listwise. A priori power calculation indicated that with N = 36, α = 0.05 and within-subject correlation r = 0.5, the study had 80% power to detect an effect size f = 0.2. Analyses were performed in SPSS.

Sample characteristics: the cohort comprised equal numbers of men and women with mean age 24.8 ± 4.2 years, mostly Caucasian (61%), and some participants with postgraduate education. All had prior MDMA exposure (range 4–40 uses). Subjective drug effects and blinding: Both MDMA doses and MA significantly increased participants' ratings of "feel drug" on the Drug Effects Questionnaire (full descriptive statistics appear in tables/supplemental figures reported in the paper). Blinding varied by session: during placebo 23 participants (63.9%) correctly guessed they had received placebo; during the MA session nine participants (25%) correctly identified receiving a stimulant; during low-dose MDMA 17 participants (47.2%) guessed MDMA; and during high-dose MDMA 25 participants (69.4%) guessed MDMA. Cardiovascular effects: Both MDMA doses and MA significantly elevated heart rate [F(3,105) = 11.33, p < 0.001] and mean arterial pressure [F(3,105) = 13.87, p < 0.001] compared with placebo. Social Feedback Task—task validity: The task produced the expected emotional pattern: rejection blocks elicited greater ratings of feeling "sad and rejected" than neutral or acceptance blocks (reported F = 43.49, p < 0.001; reject > neutral and accept p < 0.001), and acceptance blocks elicited greater ratings of feeling "happy and accepted" than neutral or rejection blocks (reported F = 70.51, p < 0.001; accept > neutral and reject p < 0.001). Primary drug effects on social feedback: The higher dose of MDMA (1.5 mg/kg) increased ratings of "happy and accepted" following social feedback (overall effect reported F = 2.92, p = 0.04); post hoc comparison of 1.5 mg/kg MDMA versus placebo was significant (p = 0.01). There were no significant differences between MDMA and MA, nor between the two MDMA doses in direct comparisons. MDMA (either dose) and MA produced no significant changes in ratings of "sad and rejected," and there were no significant dose-by-condition interactions. The authors also report no significant effects of dose order on positive or negative ratings following social feedback.

Bershad and colleagues interpret their findings as partial support for the hypotheses: high-dose MDMA enhanced positive affective responses to overt social feedback, whereas neither dose of MDMA nor MA significantly altered feelings of rejection. They situate the increased positive responses within prior literature showing that MDMA enhances reactivity to social rewards—raising pleasantness of social touch, positivity of social images, selective attention to positive faces, and related psychophysiological markers. The current results extend those findings to a more complex, personalised form of social feedback. The absence of a detectable MDMA effect on negative affect following rejection contrasts with some prior studies (for example, reduced responses in Cyberball paradigms, blunted amygdala reactivity to threat, and reductions in social anxiety). The investigators note several possible reasons: the rejection manipulation, although effective, may not have produced sufficiently strong negative affect to reveal a dampening effect; differences between implied exclusion paradigms and overt, explicit feedback may matter; and the healthy volunteer sample may differ from populations in which attenuation of negative social responses is observed. Clinical and safety implications are discussed cautiously. The authors suggest the enhancement of positive affective receptivity may be a mechanism by which MDMA facilitates psychotherapy, particularly by increasing receptiveness to an empathic therapeutic environment. They also propose potential relevance to disorders marked by social anhedonia (for example, schizophrenia, depression, PTSD, autism spectrum disorder), while emphasising that MDMA would likely be considered as an adjunct to psychosocial interventions and administered in limited, supervised sessions. At the same time, they highlight a safety concern: increased positive bias to social feedback could render individuals more vulnerable to exploitation in nonmedical settings, underscoring the need for rigorous clinical safeguards. Strengths noted by the investigators include the double-blind, placebo-controlled crossover design, inclusion of an active stimulant comparator (MA), use of two MDMA doses, and a personalised Social Feedback Task intended to maximise ecological salience. Limitations acknowledged by the authors include the simulated (not real-world) nature of the task and the decision not to induce full deception about interacting with real people, absence of plasma MDMA measurements to index drug absorption, possible lingering drug metabolism effects given 72-hour session spacing and potential delayed CYP2D6 recovery, and reliance on self-report as the primary outcome rather than objective behavioural, physiological, or neural measures. The authors conclude that their findings show MDMA, but not MA, enhanced positive affective responses to social feedback in healthy volunteers, and they call for further research to examine these effects in clinical populations and with more generalised social feedback paradigms.