Actively Recruiting
Fluoxetine and Dextromethorphan in Obsessive-Compulsive and Related Disorders: An Open-Label Crossover Pilot Study
Led by Stanford University · Updated on 2026-05-20
60
Participants Needed
1
Research Sites
87 weeks
Total Duration
On this page
Sponsors
S
Stanford University
Lead Sponsor
A
Avy L. & Roberta L. Miller Foundation
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are evaluating the tolerability and effectiveness of combining dextromethorphan, an over-the-counter cough suppressant, with fluoxetine to relieve symptoms in people with obsessive-compulsive disorder (OCD) and related disorders such as body dysmorphic disorder, somatic symptom disorder, and illness anxiety disorder. These psychiatric conditions involve recurring intrusive thoughts and repetitive behaviors that cause significant distress and disability, and current treatments may not fully address these symptoms. Participants are divided into two groups. Group A will take fluoxetine 20mg daily for 4 weeks, then continue fluoxetine while adding dextromethorphan twice daily with increasing doses over the next 4 weeks. Group B will take both fluoxetine and dextromethorphan together for 4 weeks, followed by fluoxetine alone for another 4 weeks. The dosing of dextromethorphan starts at 15mg per dose and is increased weekly as tolerated to a maximum of 60mg per dose. During the 8-week study, participants will be monitored for symptom improvement using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) at 4 and 8 weeks. Researchers will also assess clinical insight changes using the Brown Assessment of Beliefs Scale (BABS). The study involves randomized assignment to treatment sequences and includes safety monitoring. The total participation duration is 8 weeks, with symptom and insight assessments at specified intervals.
CONDITIONS
Brief Title
Study of Dextromethorphan in OCD and Related Disorders
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Diagnosis of obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), illness anxiety disorder (IAD) or somatic symptom disorder (SSD)
- Living within California
- Capacity to provide informed consent
- Age between 18 and 65 years
You will not qualify if you...
- Current bipolar disorder or psychotic disorder
- Active moderate or severe substance use disorder, lifetime severe substance use disorder
- Pregnant or nursing women
- Use of prescribed psychotropic medications other than fluoxetine for 2 weeks prior to study start
- Having commenced OCD-targeted exposure and response-prevention (ExRP) psychotherapy within 2 months of study start
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 8 weeks
Participants take fluoxetine daily for 8 weeks. Participants in one group add dextromethorphan with doses increasing weekly during the last 4 weeks, while the other group starts both drugs together for 4 weeks and then continues fluoxetine alone for 4 weeks.
Weekly visits for 8 weeks
Trial Site Locations
Total: 1 location
1
Stanford University
Stanford, California, United States, 94304
Actively Recruiting
Research Team
A
Alessa Gaeta, BA
How is the study designed?
Study Type
INTERVENTIONAL
Masking
SINGLE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
TREATMENT
Number of Arms
2
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