---
title: Role of Serotonin in Acute and Subacute MDMA Effects
nct_id: NCT00838305
overall_status: COMPLETED
phase: NA
sponsor: California Pacific Medical Center Research Institute
study_type: INTERVENTIONAL
primary_condition: MDMA Mechanism of Action
countries: United States
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT00838305.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT00838305"
ct_last_update_post_date: 2013-05-31
last_seen_at: "2026-05-12T07:07:15.213Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# Role of Serotonin in Acute and Subacute MDMA Effects

**NCT ID:** [NCT00838305](https://clinicaltrials.gov/study/NCT00838305)

## Key Facts

- **Status:** COMPLETED
- **Phase:** NA
- **Study Type:** INTERVENTIONAL
- **Target Enrollment:** 13
- **Lead Sponsor:** California Pacific Medical Center Research Institute
- **Conditions:** MDMA Mechanism of Action
- **Start Date:** 2009-02
- **Completion Date:** 2011-08
- **CT.gov Last Update:** 2013-05-31

## 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.

## Eligibility

- **Minimum age:** 18 Years
- **Maximum age:** 50 Years
- **Sex:** ALL
- **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
```

## Arms

- **Placebo** (PLACEBO_COMPARATOR) — drug: placebo subjects also get citalopram and placebo in a 2x2 crossover design
- **mdma** (EXPERIMENTAL) — drug: mdma subjects also get citalopram and placebo in a 2x2 crossover design

## Interventions

- **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

## 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** _(time frame: 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** _(time frame: post 1-4 hours)_

## Locations (1)

- CPMC Research Institute, St.Luke's Hospital, San Francisco, California, United States

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.phases` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.maxAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `outcomes.secondary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.cpmc research institute, st.luke's hospital|san francisco|california|united states` — added _(2026-05-12)_

---

*Canonical: https://parkinsonspathways.com/agent/trials/NCT00838305.md*  
*Source data (authoritative): https://clinicaltrials.gov/study/NCT00838305*  
*This page is a raw mirror with no AI summary, no editorial enrichment, and no Parkinson's-specific filtering.*