Study of Dextromethorphan in OCD and Related Disorders
Purpose
The purpose of the study is to assess the tolerability and efficacy of dextromethorphan in combination with fluoxetine for symptom relief in OCD and related disorders.
Conditions
- Obsessive-Compulsive Disorder
- Illness Anxiety Disorder
- Body Dysmorphic Disorders
- Somatic Symptom Disorder
Eligibility
- Eligible Ages
- Between 18 Years and 65 Years
- Eligible Genders
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- 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
Exclusion Criteria
- 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
Study Design
- Phase
- Phase 2
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover Assignment
- Intervention Model Description
- After signing consent and baseline assessments, participants will be randomized 1:1 to Group A or Group B for the purposes of sequencing fluoxetine vs combined fluoxetine/dextromethorphan treatment periods.
- Primary Purpose
- Treatment
- Masking
- Single (Outcomes Assessor)
- Masking Description
- Symptom rating will be done by independent evaluators blind to treatment allocation.
Arm Groups
Arm | Description | Assigned Intervention |
---|---|---|
Experimental Group A: fluoxetine then fluoxetine plus dextromethorphan |
Group A participants will take fluoxetine 20mg (or prior dose) daily for 4 weeks, and will then continue fluoxetine while adding over the counter dextromethorphan, with doses increasing weekly as tolerated, for 4 weeks. |
|
Experimental Group B: fluoxetine plus dextromethorphan then fluoxetine |
Group B participants will take fluoxetine 20mg (or prior dose) daily together with over the counter dextromethorphan, with doses increasing weekly as tolerated, for 4 weeks, and then will stop dextromethorphan, continuing fluoxetine alone for 4 weeks. |
|
Recruiting Locations
More Details
- Status
- Recruiting
- Sponsor
- Stanford University
Detailed Description
Obsessive compulsive disorder (OCD) and the related disorders body dysmorphic disorder (BDD), somatic symptom disorder (SSD) and illness anxiety disorder (IAD) are psychiatric conditions characterized by recurrent, intrusive thoughts, feelings or images (obsessions or preoccupations) and repetitive or ritualized behaviors or avoidance performed to relieve obsession or preoccupation-related anxiety. They are a significant cause of mental health-related disability, and are inadequately served by available treatments. This study tests whether an over-the-counter cough suppressant medicine, dextromethorphan, may offer symptom relief when combined with a low dose of fluoxetine, a standard prescription treatment for OCD and related disorders.