Clinical TrialNeuroimaging & Brain MeasuresPlaceboCompleted

Investigation of Serotonin Neurotransmission in MDMA Users Using Combinated Dexfenfluramine Challenge and PET Imaging

Randomised, placebo-controlled crossover neuroimaging study (n=50) using oral dexfenfluramine (40–60 mg) challenge with [18F]-altanserin PET to compare 5-HT release capacity in current MDMA users, former users, and MDMA‑naïve controls.

Target Enrollment
50 participants
Study Type
Phase NA interventional
Design
Randomized, quadruple Blind

Detailed Description

Randomised crossover design: participants receive placebo and an oral (+)dexfenfluramine challenge in random order on two days separated by seven days; PET imaging with [18F]-altanserin is performed to assess 5‑HT2A receptor availability following challenge.

On each dosing day subjects receive placebo or 60 mg (+)FEN (reported range 40–60 mg), followed two hours later by intravenous administration of ~250 MBq [18F]-altanserin and dynamic PET acquisition for 90 minutes; cognitive testing (CANTAB) and repeated psychometric measures accompany scanning.

Primary aim is to quantify serotonin release capacity and compare current and former MDMA users with controls to investigate potential long-term MDMA-related alterations in serotonergic neurotransmission and associated cognitive/affective changes.

Study Protocol

Preparation

sessions

Dosing

2 sessions
90 min each

Integration

sessions

Study Arms & Interventions

Dexfenfluramine

experimental

Oral (+)dexfenfluramine challenge (active) in crossover with placebo.

Interventions

  • Compound60 mg
    via Oral• single dose• 1 doses total

    Oral (+)FEN challenge 40–60 mg (single application); given in random order vs placebo.

Placebo

inactive

Matching placebo comparator in crossover.

Interventions

  • Placebo
    via Oral• single dose• 1 doses total

    Matching placebo capsule

Participants

Ages
18 – 45
Sexes
male

Inclusion Criteria

  • Inclusion Criteria:
  • Current and former MDMA users: lifetime use of ≥ 50 tablets of Ecstasy
  • Current MDMA users: Ecstasy use in the last 4 weeks
  • Former MDMA users: at least 1 year of abstinence of Ecstasy and other psychostimulants
  • MDMA-naïve control subjects: no lifetime use of MDMA or other psychostimulants
  • Males aged 18–45 years; medically fit for PET and challenge; consent to procedures and urine drug screening.

Exclusion Criteria

  • Exclusion Criteria:
  • Female sex
  • Positive drug urine screening (with exception for cannabis)
  • Relevant somatic, neurological or psychiatric illness
  • Current use of psychotropic medication

Study Details

  • Status
    Completed
  • Phase
    Phase NA
  • Type
    interventional
  • Design
    Randomizedquadruple Blind
  • Target Enrollment50 participants
  • Timeline
    Start: 2006-04-01
    End: 2008-07-01
  • Compound
    Placebo
  • Topic
    Neuroimaging & Brain Measures

Locations

University Hospital of Psychiatry Zurich — Zurich, Canton of Zurich, Switzerland

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