In a double‑blind, placebo‑controlled within‑participant randomised trial of 16 adults stratified by baseline nonconscious‑threat–evoked amygdala activity, 120 mg MDMA acutely reduced amygdala and subgenual ACC activity, increased sgACC–amygdala connectivity, and raised likability of threat expressions in the high‑reactivity subgroup (NTNA+) versus the low‑reactivity subgroup. These results indicate that baseline neuroimaging of negative affect circuitry can identify biomarkers to personalise MDMA‑based therapies.
Papers cited by this study that are also in Blossom
Wardle, M. C., De Wit, H. · Psychopharmacology (2014)
Importance
Rapidly acting therapeutics like 3,4-methylenedioxymethamphetamine (MDMA) are promising treatments for disorders such as posttraumatic stress disorder (PTSD). However, understanding who benefits most and the underlying neural mechanisms remains a critical gap. Stratifying individuals by neural circuit profiles could help differentiate neural, behavioral, and affective responses to MDMA, enabling personalized treatment strategies.
Objective
To investigate whether baseline stratification of individuals based on negative affect circuit profiles, particularly in response to nonconscious threat stimuli, can differentiate acute responses to MDMA.
Design, Setting, and Participants
This randomized clinical trial, implementing a double-blinded, within-participant, placebo- and baseline-controlled design, was conducted at Stanford University School of Medicine between November 2, 2021, and November 9, 2022, for wave 1 data collection. Participants had used MDMA on at least 2 prior occasions, but not in the past 6 months, and had subthreshold PTSD symptoms and early life trauma but no current psychiatric disorders. Data were analyzed from March 1, 2023, to January 1, 2024.
Interventions
Participants completed 4 visits: 1 baseline session followed by 1 placebo session and 2 MDMA sessions in a randomized order, totaling 64 visits. Baseline functional magnetic resonance imaging (fMRI) assessed the negative affect circuit using a nonconscious threat processing task (NTN).
Main Outcomes and Measures
Primary outcomes included activity and connectivity of amygdala and subgenual anterior cingulate cortex (sgACC) defining the negative affect circuit. Secondary outcomes were behavioral measures of implicit threat bias, likability of threat expressions, and affective assessments.
Results
Sixteen participants (10 [63%] female; mean [SD] age, 40.8 [7.6] years) were stratified into subgroups with high and low levels of NTN activity in the amygdala (NTNA+ [n = 8] and NTNA− [n = 8], respectively), based on a median split of baseline nonconscious threat-evoked fMRI responses. Following administration of the 120 mg of MDMA vs placebo, the NTNA+ subgroup showed significant reductions in amygdala (contrast estimate [CE], −1.43; 95% CI, −2.60 to −0.27; Cohen d, −1.22; P = .02) and sgACC activity (CE, −1.48; 95% CI, −2.42 to −0.54; Cohen d, −1.56; P = .004), increased sgACC-amygdala connectivity (CE, 0.65; 95% CI, 0.02-1.28; Cohen d, 1.02; P = .04), and increased likability of threat expressions (CE, 14.38; 95% CI, 1.46-27.29; Cohen d, 0.86; P = .03) compared with the NTNA− subgroup.
Conclusions and Relevance
In this randomized clinical trial of MDMA’s acute profiles, 120 mg of MDMA acutely normalized negative affect circuit reactivity in participants stratified by heightened amygdala reactivity at baseline, demonstrating the potential of neuroimaging to identify prospective biomarkers and guide personalized MDMA-based therapies.
Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) show substantial clinical and neurobiological heterogeneity, yet treatments are commonly applied through a trial-and-error approach. Zhang and colleagues position precision medicine in mental health as a way to overcome this limitation by stratifying individuals on the basis of neural circuit profiles derived from functional neuroimaging. Prior fMRI work has repeatedly implicated amygdala hyperactivity during nonconscious threat processing in PTSD and MDD; relationships between threat-evoked amygdala responses and ventral anterior cingulate regions, including the subgenual anterior cingulate cortex (sgACC), have varied across studies, suggesting distinct subgroups within these disorders. The amygdala and sgACC comprise a negative affect circuit thought to mediate implicit threat detection and regulation, and amygdala hyperactivity during nonconscious threat has been associated with poorer responses to first-line treatments. This study tested whether baseline stratification by negative affect circuit activity—measured during a nonconscious threat task—differentiates acute neural, behavioural, and affective responses to MDMA. Using a within-participant, double-blinded, placebo- and baseline-controlled design, the investigators administered two MDMA doses (80 mg and 120 mg) and placebo to adults with histories of early life trauma and subthreshold PTSD symptoms. They hypothesised that individuals with higher baseline threat-evoked circuit activity would show normalisation across neural, behavioural, and affective measures following acute MDMA administration compared with those with lower baseline activity. The approach aims to identify potential biomarkers to personalise MDMA-based interventions and clarify MDMA’s standalone pharmacological effects on threat circuitry.
The trial was approved by Stanford University's institutional review board and preregistered; all participants gave written informed consent and the study followed CONSORT guidelines. The investigators used a within-participants, randomised, double-blind design with a true baseline visit preceding any drug exposure. Each participant completed four visits: one baseline session, a placebo session, and two MDMA sessions (80 mg and 120 mg) in randomized order. Data collection for the reported wave occurred between November 2, 2021, and November 9, 2022. Seventeen adults aged 18–55 were recruited from the community. The extracted text does not clearly report exclusion criteria in full here, but elsewhere indicates participants had used MDMA on at least two prior occasions, had not used it in the preceding 6 months, and had subthreshold PTSD symptoms and histories of early life trauma while lacking current psychiatric disorders. The text reports stratification analyses conducted on 16 participants (see Results), so the sample actually analysed is unclear from the extraction. Primary outcomes centred on the negative affect circuit: amygdala and sgACC activity and their connectivity evoked by a nonconscious Facial Expressions of Emotion Task. Task-evoked responses (threat vs neutral faces) were measured by fMRI approximately 90 minutes after drug or placebo administration and expressed as z scores relative to a healthy reference dataset (n = 50). Secondary measures included a behavioural implicit emotion bias test (WebNeuro implicit recognition of facial emotions), where implicit threat bias was operationalised as reaction time for angry minus neutral faces and standardised against age-matched norms; a facial likability rating (0–100) for faces seen in the fMRI task; affective self-report via visual analogue scales (VAS) including items such as "I want to be with other people" and "I feel secure"; and selected subscales of the Five-Dimensional Altered States of Consciousness (5D-ASC) assessing Anxiety and Impaired Control and Cognition. Participants’ narrative descriptions were also recorded. For analysis, the investigators stratified participants at baseline by amygdala response to nonconscious threat using a median split into NTN A+ and NTN A- subgroups. Linear mixed-effects models tested effects of baseline subgroup, dose (placebo, 80 mg, 120 mg), and their interaction, with covariates (age, biological sex, percentage of motion spikes) included when associated with outcomes. The primary contrasts emphasised were placebo versus 120 mg and placebo versus 80 mg. Effect sizes were reported as Cohen's d and statistical significance was set at two-sided P < .05. Multiple imputation was used to address missing values in sensitivity checks. Masking (blinding) integrity was assessed by asking clinicians, coordinators, and participants to identify dose conditions.
This study was approved by the Stanford University Institutional Review Board and was preregistered on August 6, 2019. All participants provided written informed consent. Details of the trial protocol, participants, visits, and assessments are presented in Supplement 1 (trial protocol) and eMethods in Supplement 2. This study followed the Consolidated Standards of Reporting Trials (CONSORT) reporting guideline.
Data were analyzed from March 1, 2023, to January 1, 2024. To evaluate the differentiating value of baseline stratification on primary and secondary outcomes, linear mixed-effects models were implemented with baseline subgroup (NTN A+ or NTN A-), dose (placebo, 80 mg of MDMA, or 120 mg of MDMA), and subgroup-by-dose interaction as fixed effects, using the nlme package of R, version 1.1.162.Covariates, including age, biological sex, and the percentage of motion spikes, were included if they were found to associate with outcomes. We focused on the between-subgroup difference between the placebo and the 120-mg MDMA dose, as well as between the placebo and the 80-mg MDMA dose. Effect sizes were calculated as Cohen's d using the effectsize package (R, version 0.8.3).Statistical significance was defined as a 2-sided P < .05.
Our findings in this randomized clinical trial demonstrate the importance of stratifying individuals by baseline circuit activity to differentiate acute MDMA-induced neural, behavioral, and affective responses. Specifically, following acute administration of 120 mg of MDMA, participants in the NTN A+ subgroup exhibited significant reductions in amygdala and sgACC activity, as well as increased connectivity between these regions. These results underscore the potential of using neural circuit markers not only to stratify patients based on threat reactivity, but also to quantify the mechanismspecific responses elicited by MDMA. Notably, the negative affect circuit markers that stratified participants and exhibited acute changes with MDMA were elicited during the nonconscious processing of threat stimuli. Implicit threats directly engage the amygdala, enabling the detecting of danger on an unconscious level, bypassing cognitive systems.The sgACC is functionally connected to the amygdala in response to implicit threatsand plays a key role in the implicit regulation of amygdala activity.Heightened amygdala activity during nonconscious threat processing is a well-established marker of threat reactivity in both PTSD and MDD,and it has been linked to poor responses to medication and psychotherapies.In PTSD, successful therapeutic extinction of implicit threat conditioning has been associated with increased amygdala-sgACC connectivity,highlighting the importance of this circuit in therapeutic outcomes. In the NTN A+ subgroup, the 120-mg MDMA dose alone-without accompanying therapy but within a supportive research environment-significantly reduced threat-related amygdala activity. This result aligns with prior fMRI findings in nonclinical participantsbut is specific to the MDMA dose of 120 mg. It reinforces the understanding of MDMA-assisted therapy, in which MDMA dampens automatic threat reactivity,enabling individuals to engage more emotionally with threat-and trauma-related memories. Our findings suggest that the pharmacological effects of MDMA play a crucial role in creating a more receptive neural state for processing trauma-related information. Additionally, the observed increase in amygdala-sgACC connectivity in the NTN A+ subgroup following MDMA administration indicates that these effects may enhance the implicit regulation of threat-or trauma-related stimuli. This implicit regulation facilitates contextual processing, potentially enabling participants to shift from hyperengagement with traumatic material to more integrated and contextually grounded processing.While our study used a supportive environment without any structured trauma therapy, pairing MDMA with therapy may further enable reappraisal of traumatic material within a controlled clinical setting. Participants in the NTN A+ subgroup who demonstrated high baseline amygdala activity also exhibited a bias toward implicit priming by the same threat stimuli used during fMRI. This bias was reflected in slowed reaction times to implicit priming, suggesting a heightened reactivity toward threat detection. These findings indicate that implicit priming serves as a behavioral surrogate for circuit-based markers activated by implicit threat stimuli, making it useful to complement fMRI measures for stratifying participants. Building on the neural findings, the NTN A+ subgroup also showed an increase in the likability ratings of threat faces under the 120-mg dose of MDMA. This suggests MDMA's potential to soften the emotional impact of threat-related stimuli in individuals with heightened baseline negative affect circuit activity. However, the NTN A+ subgroup reported subjective feelings of increased anxiety, despite the reduction in both amygdala activity and increased likeability for threat stimuli. These subjective feelings could reflect the discomfort of engaging with threat-related material, consistent with previous observations.Stratification in our study offers a promising approach for future US Food and Drug Administration (FDA) trials by identifying responders and nonresponders prior to treatment, enabling more targeted participant selection. This strategy can streamline trial designs, improve efficiency, and accelerate the development of MDMA-based therapies. Moreover, it mitigates potential risks, such as MDMA-induced vulnerability or misuse, ensuring safer and more effective clinical applications. Our study provides insights into the standalone pharmacological effects of MDMA, aligning with the FDA's call to better understand MDMA independent of therapy.By including a true baseline visit, we accurately measured predrug neural activity, ensuring that effects observed between the NTN A+ and NTN A-subgroups were not conflated with placebo responses. The addition of an 80-mg MDMA condition alongside the 120-mg dose reduced functional unmasking by lowering participants' ability to identify treatment conditions, with accuracy notably lower than in MDMA-assisted therapy trials,particularly for individuals in the NTN A-subgroup, in which accuracy ranged from 50% to 60%.
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Mitchell, J., Bogenschutz, M. P., Lilienstein, A. et al. · Nature Medicine (2021)
Mitchell, J., Ot’alora G, M., van der Kolk, B. et al. · Nature Medicine (2023)
Studerus, E., Vizeli, P., Harder, S. et al. · Journal of Psychopharmacology (2021)
Papers in Blossom that reference this study
Thuery, G., Crossen, F., Mc Loone, D. et al. · Therapeutic Advances in Psychopharmacology (2026)
Baseline stratification divided participants into NTN A+ (high threat-evoked amygdala activity) and NTN A- (low activity) subgroups using a median split, each with eight participants according to the extracted text. The NTN A+ subgroup had mean amygdala z scores above the healthy reference (mean z = 1.09) while the NTN A- subgroup had mean z below the reference (mean z = -0.57). The NTN A+ subgroup showed significantly greater amygdala activity than the NTN A- subgroup at baseline (mean difference 1.66; 95% CI, 1.00–2.32; Cohen d = 2.7; P < .001). Behaviourally, NTN A+ participants exhibited a larger implicit threat bias at baseline, with slower reaction times when implicitly primed with angry versus neutral faces (mean difference -0.93; 95% CI, -1.61 to -0.26; Cohen d = -1.48; P = .01). The investigators report that these subgroup differences were not attributable to baseline demographics, overall symptom severity, or early life trauma as measured in the study, although a relatively greater distribution of PTSD symptoms and traumatic events was seen in NTN A+ (supplementary figures referenced). For acute drug effects, distinct differences emerged for the 120 mg MDMA dose when compared with placebo in the NTN A+ versus NTN A- subgroups. In the NTN A+ subgroup, 120 mg MDMA produced significant reductions in threat-evoked amygdala activity (contrast estimate [CE] -1.43; 95% CI, -2.60 to -0.27; Cohen d = -1.22; P = .02) and sgACC activity (CE -1.48; 95% CI, -2.42 to -0.54; Cohen d = -1.56; P = .004). The same subgroup also showed an increase in sgACC–right amygdala connectivity (CE 0.65; 95% CI, 0.02–1.28; Cohen d = 1.02; P = .04). These neural changes were specific to the 120 mg dose in the reported comparisons. On behavioural and affective outcomes, implicit threat bias did not differ significantly between subgroups in response to MDMA (CE 0.45; 95% CI, -0.49 to 1.39; Cohen d = 0.38; P = .34). Perceived likability of threat faces, however, increased significantly in the NTN A+ subgroup under 120 mg MDMA compared with NTN A- (CE 14.38; 95% CI, 1.46–27.29; Cohen d = 0.86; P = .03), with effects particularly noted for angry faces. Self-reported affect showed subgroup differences for some items: the extracted text is truncated for one contrast (reporting that NTN A+ reported less increase in "wanting to be with others" with incomplete CI reporting), but it does report no significant increase in Impaired Control and Cognition (CE 11.07; 95% CI, -0.53 to 22.67; Cohen d = 0.74; P = .06). Narrative reports aligned with quantitative measures: NTN A+ participants described more introspective and emotionally nuanced experiences during 120 mg MDMA, whereas NTN A- participants described more positive and euphoric experiences. Results were robust to multiple imputation for missing data according to supplementary analyses. Masking outcomes showed that dose conditions were correctly identified across visits in 85% of clinician ratings (39 of 46), 81% of research coordinator ratings (38 of 47), and 77% of participant ratings (34 of 44). Accuracy was highest for placebo and lower for both MDMA doses; accuracy was notably lower in the NTN A- subgroup (reported range 50%–60% for some conditions).
Zhang and colleagues interpret their findings as evidence that baseline stratification by negative affect circuit activity can differentiate acute neural, behavioural, and affective responses to MDMA. They highlight that, following a single 120 mg dose of MDMA administered in a supportive research environment without structured therapy, participants with high baseline amygdala activity (NTN A+) exhibited reduced amygdala and sgACC activation in response to nonconscious threat and increased amygdala–sgACC connectivity. The investigators view these changes as a regularisation of threat circuitry, consistent with the idea that MDMA pharmacology can dampen automatic threat reactivity and thereby create a neural state more receptive to emotional engagement. The authors situate their results within prior literature showing amygdala hyperactivity during nonconscious threat in PTSD and MDD and note that increased amygdala–sgACC connectivity has been associated with successful extinction of implicit threat conditioning. They propose that the observed connectivity increase may reflect enhanced implicit regulation of threat, promoting more contextualised processing of trauma-related stimuli. Behavioural findings—particularly increased likability ratings of threat faces in the NTN A+ subgroup—are discussed as evidence that MDMA can soften the emotional salience of threat-related cues. At the same time, the NTN A+ subgroup reported some increases in subjective anxiety despite neural reductions, which the authors suggest may reflect the discomfort of emotional engagement with threat material even as neural markers move toward normalisation. Practical implications emphasized by the investigators include the potential use of circuit-based stratification to identify likely responders for future clinical trials, thereby improving trial efficiency and reducing risks associated with MDMA administration. They note that inclusion of a true baseline visit improved their ability to dissociate drug effects from placebo responses and that adding the 80 mg condition reduced unmasking compared with typical MDMA-assisted therapy trials. Key limitations acknowledged in the extracted text include the small sample size and the need for validation in larger cohorts; the authors recommend further clinical studies to determine whether the acute circuit changes observed translate to therapeutic outcomes when MDMA is paired with structured psychotherapy.