Role of Serotonin in Acute and Subacute MDMA Effects

Brief Summary

The purpose of this study is to measure the effects of MDMA (particularly its emotional effects) and to determine the role of serotonin in these effects. Serotonin is a neurotransmitter, which is a chemical that is released by some brain cells to communicate with other brain cells. Many of the effects of MDMA are thought to be the result of increased serotonin release. In order to understand the effects of MDMA and role of serotonin in these effects, we will administer MDMA alone and in combination with the antidepressant citalopram (one trade name for this is Celexa). Citalopram decreases the ability of MDMA to release serotonin. Citalopram will therefore decrease any of MDMA's effects that are the result of serotonin release; we want to measure this.

Intervention / Treatment

  • MDMA and citalopram (DRUG)
    MDMA 1.5 mg/kg and citalopram 20 mg
  • Placebo (DRUG)
    drug: placebo subjects also get citalopram and placebo in a 2x2 crossover design

Condition or Disease

  • MDMA Mechanism of Action


  • Not Applicable
  • Study Design

    Study type: INTERVENTIONAL
    Status: Completed
    Study results: No Results Available
    Age: 18 Years to 50 Years
    Enrollment: 13 (ACTUAL)
    Funded by: Other
    Allocation: Randomized
    Primary Purpose: Basic Science


    • Participant
    • Investigator

    Clinical Trial Dates

    Start date: Feb 01, 2009
    Primary Completion: Dec 01, 2009 ACTUAL
    Completion Date: Aug 01, 2011 ACTUAL
    Study First Posted: Feb 06, 2009 ESTIMATED
    Results First Posted: Aug 30, 2020
    Last Updated: May 29, 2013

    Sponsors / Collaborators

    Responsible Party: N/A

    Participant Groups

    • drug: placebo subjects also get citalopram and placebo in a 2x2 crossover design

    • drug: mdma subjects also get citalopram and placebo in a 2x2 crossover design

    Eligibility Criteria

    Sex: All
    Minimum Age: 18
    Maximum Age: 50
    Age Groups: Adult
    Healthy Volunteers: Yes

    Inclusion Criteria:

    * Healthy men or women aged 18 to 50 years
    * Experienced with MDMA

    Exclusion Criteria:

    * Significant physical or psychiatric illness which might impair the ability to safely complete the study or that might be complicated by the study drugs, including prior seizures (after age 8), history of major depression, or other active neurological disease or clinically significant abnormalities on physical examination or screening laboratory values

    Primary Outcomes
    • To determine if administration of the selective serotonin reuptake inhibitor (SSRI) citalopram decreases the subacute (post 24hr) discontinuation effects of MDMA in experienced MDMA users given a modest dose of MDMA 24 hours
    Secondary Outcomes
    • To determine if administration of the SSRI citalopram decreases the acute (post 1 to 4hr) social and emotional and cognitive effects of MDMA post 1-4 hours

    More Details

    NCT Number: NCT00838305
    Other IDs: 28.065-1
    Study URL:
    Last updated: Sep 29, 2023