Study of Dextromethorphan in OCD and Related Disorders

Obsessive-Compulsive Disorder Clinical Trial

Official title:

Fluoxetine/Dextromethorphan in Obsessive-Compulsive and Related Disorders: an Open-Label Crossover Pilot Study

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04899687
• Other study ID #: 60569
• Status: Recruiting
• Phase: Phase 2
• Start date: January 20, 2022
• Est. completion date: December 1, 2025

Study information

• Verified date: April 2024
• Source: Stanford University
• Contact: Pavithra Mukunda, MS
• Phone: 650 497 2578
• Email: ocdresearch[@]stanford.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 60
• Est. completion date: December 1, 2025
• Est. primary completion date: April 1, 2025
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

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

Related Conditions & MeSH terms

• Anxiety Disorders
• Body Dysmorphic Disorders
• Illness Anxiety Disorder
• Medically Unexplained Symptoms
• Obsessive-Compulsive Disorder
• Somatic Symptom Disorder

Intervention

Drug:
• Fluoxetine
Fluoxetine 20mg (or previously prescribed dose) will be taken once daily by mouth for 8 weeks
• Dextromethorphan
Dextromethorphan, an over-the-counter cough suppressant, will be taken by mouth twice daily for four weeks of the study, starting at 15mg per dose, and increasing weekly as tolerated to a maximum of 60mg per dose.

Locations

Country	Name	City	State
United States	Stanford University	Stanford	California

Sponsors (2)

Lead Sponsor	Collaborator
Stanford University	Avy L. & Roberta L. Miller Foundation

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Improvement in OCD or related disorder symptoms as measured by the Y-BOCS	Improvement in OCD severity is measured by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), a gold standard measure of the severity of obsessions and compulsions. Variants of the Y-BOCS designed for assessment of body dysmorphic disorder or illness anxiety disorder/somatic symptom disorder will be used as appropriate. Y-BOCS scores range from 0 to 40, with higher scores indicating greater severity of symptoms. Response will be defined as a 35% reduction in Y-BOCS score.	Change from baseline will be assessed at 4 weeks and at 8 weeks.
Secondary	Improvement in clinical insight as measured by the BABS	Improvement in clinical insight is measured by the Brown Assessment of Beliefs Scale (BABS), a scale assessing multiple dimensions of clinical insight as relevant to OCD and related disorders. The BABS rates multiple dimensions of clinical insight related to an identified belief. BABS scores range from 0-24, with higher scores indicating greater insight impairment. Response will be defined as a 35% reduction in BABS score.	Change from baseline will be assessed at 4 weeks and at 8 weeks.