OCD Biomarker Survey Employing sEEG and Stimulation: The OBSESS Trial (OBSESS)

Brown University, Carnegie Mellon University, Duke University, William Marsh Rice University, University of Washington, Mclean Hospital

Obsessive-compulsive disorder (OCD) has a lifetime prevalence of 2-3% and is a major cause of global disability. Deep brain stimulation (DBS) is an effective treatment for patients with severe, treatment-resistant forms, but access to and utilization of this therapy remains minimal despite FDA approval via HDE. The investigator's goal is to determine the neurophysiological basis of key symptom domains underlying OCD and derive individual-specific stimulation parameters to improve consistency of outcomes and facilitate outpatient therapy delivery. To do so, the investigators take advantage of key novel DBS device features, including imaging-based "inverse solutions" to determine optimal stimulation parameters, as well as on-device neural recordings that will guide therapy delivery. The investigators will recruit patients with OCD meeting established criteria for surgical evaluation. Each will be implanted with permanent DBS leads and temporary stereo-EEG (sEEG) electrodes. In the inpatient unit, the investigators will first demonstrate how these DBS leads anatomically engage these hub-like DBS target regions and physiologically affect pre-frontal networks. In the outpatient phase, the investigators implement the inverse solutions parameters in a double-blinded head-to-head trial to test whether these personalized parameter sets can reduce symptoms in the domain-specific manner in which the personalized parameters were designed. Doing so would be the first demonstration of data-derived, individual specific DBS programming. Demonstrating clinical outcomes comparable to those achieved by expert programmers but with software-generated stimulation parameters will help demystify the programming process and increase accessibility to this therapy. Finally, and critically, patients will provide chronic on-device recordings labeled with behavioral data from wearables and portables. These naturalistic data will transform the investigator's understanding of the physiological signatures of OCD and provide biomarkers of symptom severity, therapeutic response, and potentially side effects, which will guide future therapy.

Severity of depression symptoms. Changes in the Yale-Brown Obsessive Compulsive Scale survey/questionnaire. YBOCS is an assessment to rate symptoms of OCD on a scale of 0-50 (with a higher number indicating a more severe outcome ratings of OCD and 0 indicated no symptoms of OCD).

Severity of depression symptoms. Changes in the Hamilton Depression Inventory (HAM-D) score. HAM-D is an assessment to rate symptoms of depression on a scale of 0-52 (with a higher number indicating a more severe outcome ratings of depression and 0 indicated no symptoms of depression).

Inclusion Criteria: Principal diagnosis of OCD, confirmed by Structured Clinical Interview for DSM-IV (SCID-IV), judged of disabling severity with a Yale-Brown Obsessive Compulsive Scale (YBOCS) score of at least 28; Men and women (non-pregnant) between ages 21 and 70; The patient has had at least a five-year history of treatment-refractory OCD that causes substantial subjective distress and impairment in functioning; Comorbid signs and symptoms of depression deemed secondary (based on history and clinical judgment) to OCD with minimum score of 16 on the HAM-D; Has failed an adequate trial (≥3 months at the maximum tolerated therapeutic dose) of at least three of the following SSRIs: fluoxetine; fluvoxamine; citalopram; escitalopram; sertraline; paroxetine; Has failed an adequate trial (150 - 250 mg) of clomipramine; Has failed augmentation of one or more of the aforementioned drugs with at least one of the following antipsychotics: haloperidol; risperidone; quetiapine; zisprasidone; aripiprazole; Must have failed an adequate trial of CBT for OCD; defined as ≥20 sessions of documented exposure and response prevention (ERP) by an expert therapist; Stable psychotropic medical regimen for the month preceding surgery; Able to provide fully informed, written consent; A family member or significant other is available and willing to communicate with the research team if the patient's clinical status worsens (e.g., develops hypomania), and if necessary to accompany patients to study visits. Exclusion Criteria: Has a lifetime diagnosis of psychotic disorder such as schizophrenia; Comorbid Tourette's Disorder is exclusionary if the tic symptoms are the same presenting problem or at equivalent severity/impairment with OCD symptoms; Alcohol or substance abuse/dependence within 6 months, excluding nicotine; Deemed at high risk of suicidal behavior or impulsivity; MMSE score < 24; Premorbid IQ estimate < 85; Any neurological or medical condition/disorder that makes the patient, in the opinion of the surgeon, a poor candidate to undergo the intended surgical procedures of the study; Pregnant or plans to become pregnant in the next 24 months; Need for diathermy; Anticipated need for periodic MRI scans; Any psychiatric disorder that, in the opinion of the Scientific Steering Group, may interfere with the candidate's ability to participate in study activities.