Caloric Vestibular Stimulation for Modulation of Insight in Obsessive-Compulsive Spectrum Disorders

Study Overview
=================
Brief Summary
-----------------
This study investigates whether caloric vestibular stimulation can modulate a measure of insight in obsessive-compulsive spectrum disorders.

Detailed Description
-----------------
Obsessive-compulsive and related disorders (OCRD), including obsessive compulsive disorder and body dysmorphic disorder, are chronic and disabling conditions characterized by recurrent intrusive thoughts and associated compulsive behaviors that affect millions of individuals in the US each year. Individuals affected by OCRD differ in insight, or the degree to which they understand their intrusive thoughts to reflect illness. Impairments in insight limit individuals' motivation to engage in care and predict worse outcome in those who access treatment. This study seeks to explore whether unilateral stimulation of the vestibular system, which activates cortical areas hypothesized to underlie clinical insight, may beneficially modulate insight in individuals with OCRD.

Official Title
-----------------
Caloric Vestibular Stimulation for Modulation of Insight in Obsessive-Compulsive Spectrum Disorders

Conditions
-----------------
Obsessive-Compulsive Disorder, Body Dysmorphic Disorders, Illness Anxiety Disorder

Intervention / Treatment
-----------------
* Other: Caloric Vestibular Stimulation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age 18-65 Primary diagnosis of Obsessive-Compulsive Disorder, Body Dysmorphic Disorder, Illness Anxiety Disorder or Somatic Symptom Disorder (excluding with predominant pain) Strongly held OCRD-related concerns meeting BABS score criterion. No recent change in psychopharmacological treatment, if any Capacity to provide informed consent Exclusion Criteria: Psychiatric or medical conditions (eg, vertigo, history of otological surgery) that might make participation unsafe Pregnant or nursing women Active or recent substance use

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: randomized, controlled crossover study
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: right cold caloric vestibular stimulation<br>OCRD participants in this arm will receive an approx 60 second infusion of distilled cold(4)c water in their right external ear canal, with before and after measures of OCRD symptom severity and insight. | Other: Caloric Vestibular Stimulation<br>* Cold water creates a convection current in the semicircular canal of the vestibular apparatus, leading to brief (<3 min) and typically well tolerated sense of rotational movement. Similar stimulation is routinely used in standard vestibular diagnostic testing.<br>|
| Experimental: left cold caloric vestibular stimulation<br>OCRD participants in this arm will receive an approx 60 second infusion of distilled cold(4)c water in their left external ear canal, with before and after measures of OCRD symptom severity and insight. | Other: Caloric Vestibular Stimulation<br>* Cold water creates a convection current in the semicircular canal of the vestibular apparatus, leading to brief (<3 min) and typically well tolerated sense of rotational movement. Similar stimulation is routinely used in standard vestibular diagnostic testing.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in clinical insight as measured by the Brown Assessment of Beliefs (BABS). | Changes in clinical insight will be rated using the BABS, a gold-standard measure for assessing multiple dimensions of clinical insight across psychiatric disorders. The BABS is a 24 point scale for which scores ≥13 suggest poor or absent insight. | 1 hour | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Insight, Caloric Vestibular Stimulation