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Therapeutic Alliance and Perceived Closeness in MDMA-Assisted Therapy for Social Anxiety Disorder

Joseph M. Diehl, Christina Chwyl, Liliana Kennedy, Jenna Lejeune, Jason B. Luoma

September 11, 2026 preprint DOI: 10.31234/osf.io/tezgw_v1 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Preregistered secondary analysis of an open-label pilot trial Pilot study
Sample size 20
Population Adults with social anxiety disorder (SAD)
Interventions 3 4-methylenedioxymethamphetamine-assisted therapy (MDMA-AT)
Duration Three preparation sessions, two MDMA dosing sessions, and six integration sessions
Measures Agnew Relationship Measure, Inclusion of Other in the Self Scale, Liebowitz Social Anxiety Scale
Topics Anxiety MDMA
Key findings Therapeutic alliance was high after preparation and increased significantly after the first MDMA session, with ceiling effects later. Perceived closeness to the therapist increased significantly during each MDMA session and decreased during the nondrug interval. Greater MDMA-session closeness predicted lower post-treatment social anxiety, including after adjustment for pre-MDMA closeness, and was associated with self-transcendent emotions and connection-related experiences.

Abstract

The therapeutic relationship is considered central to psychedelic-assisted therapy, yet little empirical research has examined how it changes during 3,4-methylenedioxymethamphetamine-assisted therapy (MDMA-AT) or relates to acute MDMA experiences and clinical outcomes, particularly for social anxiety disorder (SAD). This preregistered secondary analysis examined therapeutic alliance and perceived closeness during an open-label pilot trial of MDMA-AT for SAD (N = 20; NCT-redacted-for-anonymous-review). Participants completed three preparation sessions, two MDMA dosing sessions, and six integration sessions. Therapeutic alliance and therapist closeness were assessed before and after each MDMA session using the Agnew Relationship Measure and Inclusion of Other in the Self Scale, respectively. Social anxiety severity was assessed with the Liebowitz Social Anxiety Scale at baseline and post-treatment, and self-transcendent experiences were assessed following MDMA sessions. Alliance was high after preparation and increased significantly following the first MDMA session, with evidence of ceiling effects later in treatment. Closeness increased significantly during each MDMA session and decreased during the subsequent nondrug interval. Greater MDMA-session closeness predicted lower post-treatment social anxiety, including after adjustment for corresponding pre-MDMA closeness. Self-transcendent emotions and connection-related experiences were associated with greater MDMA-session closeness, and pre-dosing closeness predicted greater self-transcendent emotions during the subsequent MDMA session. These findings distinguish more stable therapeutic alliance from more dynamic felt interpersonal closeness and suggest that closeness may be a particularly sensitive relational process in MDMA-AT for SAD.