Negative Affect Circuit Subtypes and Neural, Behavioral, and Affective Responses to MDMA: A Randomized Clinical Trial.

In a double-blind, placebo-controlled trial, 16 adults with subthreshold PTSD symptoms and early life trauma but no current psychiatric disorders were given 120 mg of MDMA or placebo. Participants were split into two groups based on baseline brain activity in the amygdala in response to nonconscious threat cues: those with high amygdala reactivity (NTNA+) and those with low reactivity (NTNA-). MDMA, compared with placebo, reduced activity in the amygdala and subgenual anterior cingulate cortex (sgACC), increased connectivity between the sgACC and amygdala, and increased liking of threatening facial expressions, but only in the NTNA+ subgroup. These findings suggest that baseline neural circuit profiles can identify who may benefit most from MDMA therapy and point to possible biomarkers for personalized treatment.

Study at a glance

Abstract

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. 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. 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. 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). 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. 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. 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. ClinicalTrials.gov Identifier: NCT04060108.