Neural Mechanisms of the Sensorymotor Circuit in Sensory Phenomena in OCD

Neural Mechanisms of the Insula-Supplementary Motor Area Circuit in Sensory Phenomena in Obsessive-Compulsive Disorder

The goal of this clinical study is to investigate the neural mechanisms of abnormal sensory phenomena in patients with Obsessive-Compulsive Disorder and to evaluate whether modulation of the insula-supplementary motor area circuit can improve these symptoms. The study will include adult patients with OCD (with or without sensory phenomena) and healthy volunteers.

The main questions it aims to answer are:

• Do patients with OCD show abnormal activity in the insula-SMA circuit compared with healthy controls?
• Is this abnormality associated with the presence and severity of abnormal sensory phenomena?
• Can low-frequency rTMS targeting the Supplementary Motor Area improve sensory phenomena and obsessive-compulsive symptoms? Researchers will compare an on-line rTMS group (viewing body-focused videos during stimulation) with an off-line rTMS group (resting during stimulation) to evaluate whether task engagement enhances treatment effects.

Participants will:

• Complete clinical assessments and behavioral tasks.
• Undergo EEG and fMRI assessments.
• Receive low-frequency rTMS targeting the Supplementary Motor Area.
• Repeat assessments after the intervention.

Study Overview

• Status: Not yet recruiting
• Conditions: Obsessive - Compulsive Disorder
• Intervention / Treatment: Device: repetitive transcranial magnetic stimulation (rTMS)

Detailed Description

Phase 1:

This part adopts a cross-sectional design. A total of 30 patients with Obsessive-Compulsive Disorder with sensory phenomena, 30 OCD patients without sensory phenomena, and 30 healthy controls will be recruited. Clinical assessments will be conducted, including evaluation of the severity of sensory phenomena, as well as obsessive-compulsive, depressive, and anxiety symptoms. Resting-state functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) data will be collected. In addition, during a body-focused video task designed to activate the insula-SMA circuit, task-based fMRI-EEG data will be simultaneously acquired.

Phase 2:

This part adopts a randomized parallel controlled design. Based on the 30 OCD patients with sensory phenomena included in Phase 1, an additional 30 patients will be recruited, resulting in a total of 60 OCD patients with sensory phenomena. After completing baseline clinical scale assessments, behavioral tasks, fMRI, and EEG data collection, participants will be randomly assigned to an on-line group or an off-line group. Both groups will receive low-frequency repetitive transcranial magnetic stimulation (rTMS) targeting the Supplementary Motor Area for six consecutive days, with five sessions per day. In the on-line group, participants will watch body-focused sensory videos during each stimulation session, whereas the off-line group will remain at rest during stimulation. After completion of the intervention, clinical scale assessments, behavioral tasks, and fMRI and EEG data collection will be repeated.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jiayue Cheng, Master; Phone Number: +8602134773503; Email: chengjy_94@163.com

Study Locations

• China
  • Shanghai, China
    • Shanghai Mental Health Center
    • Contact: Jiayue Cheng, Master; Phone Number: +8602134773503; Email: chengjy_94@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

OCD with abnormal sensory phenomena

1. Meet the diagnostic criteria for Obsessive-Compulsive Disorder according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
2. Aged 18-55 years.
3. Score ≥16 on the Yale-Brown Obsessive Compulsive Scale, indicating moderate to severe symptoms.
4. Score >6 on the Sensory Phenomena Scale (SPS), indicating moderate to severe sensory phenomena.
5. Right-handed.
6. Either medication-free or on stable medication for at least 8 weeks.

OCD without abnormal sensory phenomena

1. Meet the diagnostic criteria for Obsessive-Compulsive Disorder according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
2. Aged 18-55 years.
3. Score ≥16 on the Yale-Brown Obsessive Compulsive Scale.
4. Score ≤6 on the Sensory Phenomena Scale (SPS).
5. Right-handed.
6. Either medication-free or on stable medication for at least 8 weeks.

Exclusion criteria

1. Meeting diagnostic criteria in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition for psychiatric disorders other than OCD or obsessive-compulsive personality disorder.
2. OCD symptoms so severe that required assessments cannot be completed.
3. Presence of severe suicidal ideation or high suicide risk.
4. Pregnant women or women planning pregnancy in the near future.
5. History of epilepsy or any medical condition that may induce seizures or intracranial hypertension.
6. Contraindications to MRI, such as metallic implants.
7. Clinically significant medical illnesses or abnormal laboratory findings.
8. Inability to complete study procedures due to severe symptoms, low cognitive functioning, or poor cooperation.

Healthy Controls Inclusion criteria

1. No current or past psychiatric disorders meeting diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
2. Aged 18-55 years.
3. Right-handed. Exclusion criteria

1. Pregnant women or women planning pregnancy in the near future. 2. History of epilepsy or any medical condition that may induce seizures or intracranial hypertension.

3. Presence of severe suicidal ideation or high suicide risk. 4. Contraindications to MRI, such as metallic implants. 5. Clinically significant medical illnesses or abnormal laboratory findings. 6. Inability to complete study procedures due to severe symptoms, low cognitive functioning, or poor cooperation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: online group; The on-line group will watch body-focused sensory videos during each rTMS session.	Device: repetitive transcranial magnetic stimulation (rTMS); Repetitive transcranial magnetic stimulation (rTMS) will be delivered at 1 Hz with a total of 1,200 pulses per session, administered five times per day for six consecutive days. Target localization will be based on each participant's T1-weighted structural MRI, using a neuronavigation system to establish an individualized head model and identify the Supplementary Motor Area. The stimulation intensity will be set at 110% of the individual resting motor threshold (RMT).
Active Comparator: off-line group; The off-line group will remain at rest during each rTMS sessions.	Device: repetitive transcranial magnetic stimulation (rTMS); Repetitive transcranial magnetic stimulation (rTMS) will be delivered at 1 Hz with a total of 1,200 pulses per session, administered five times per day for six consecutive days. Target localization will be based on each participant's T1-weighted structural MRI, using a neuronavigation system to establish an individualized head model and identify the Supplementary Motor Area. The stimulation intensity will be set at 110% of the individual resting motor threshold (RMT).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Yale-Brown Obsessive Compulsive Scale(Y-BOCS) score	It assesses the severity of OCD symptoms. The Y-BOCS scale ranges from 0 to 40, with 0 being no symptoms and 40 being severe.	Up to 6 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Sensory Phenomena Scale (SPS) score	A semi-structured scale used to assess the presence and severity of sensory phenomena occurring before or during repetitive behaviors. It consists of two parts: a symptom checklist and a severity rating.	Up to 6 days
Change in Beck Depression Inventory(BDI) score	It consists of 21 items and uses a 0 to 3 severity scale. Total scores range from 0 to 63, with higher scores indicating more severe depression symptoms.	Up to 6 days
Change in Beck Anxiety Inventory (BAI) score	It is an inventory of anxiety symptoms with 18 items that are rated on a 5-point Likert scale(0 to 4). Total scores range from 0 to 72, with higher scores indicating more severe anxiety symptoms.	Up to 6 days
Change in Perceived Stress Scale(PSS) score	It is a 10-item, 5-point Likert scale(0 to 4) to measure the degree to which situations in one's life are appraised as stressful.The total score ranges from 0 to 40, with lower total scores representing a better outcome.	Up to 6 days
Change in Obsessive-Compulsive Inventory-Revised (OCI-R) score	It is a self-report instrument derived from the original 42-item OCI for assessing obsessive-compulsive symptoms. It contains 18 items divided into six subscales, each with three items, assessing six symptom dimensions: washing, obsessing, hoarding, ordering, checking, and neutralizing. Each item is rated on a 5-point scale from 0 to 4, with higher scores indicating more severe symptoms.	Up to 6 days
Change in Obsessive Beliefs Questionnaire (OBQ) score	This scale consists of 44 items and includes three factors: responsibility/threat estimation, perfectionism/certainty, and importance/control of thoughts.	Up to 6 days
Change in Intolerance Of Uncertainty Scale (IUS-12) score	This scale consists of 12 items rated on a 5-point Likert scale ranging from "strongly disagree" to "strongly agree." Higher scores indicate lower tolerance of uncertainty. The scale includes two dimensions: inhibitory anxiety and prospective anxiety.	Up to 6 days
Change in Intolerance Of Not Just Right Experiences Questionnaire Revised, (NJRE-Q-R) score	This scale is used to assess the presence and severity of Not Just Right Experiences in individuals.	Up to 6 days

Collaborators and Investigators

• Sponsor: Shanghai Mental Health Center

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: March 13, 2026
• First Submitted That Met QC Criteria: March 13, 2026
• First Posted (Actual): March 18, 2026

Study Record Updates

• Last Update Posted (Actual): March 20, 2026
• Last Update Submitted That Met QC Criteria: March 18, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: obsessive-compulsive disorder; neuromodulation; insula; supplementary motor area; sensory phenomena
• Additional Relevant MeSH Terms: Mental Disorders; Personality Disorders; Anxiety Disorders; Compulsive Personality Disorder; Obsessive-Compulsive Disorder; Therapeutics; Magnetic Field Therapy; Transcranial Magnetic Stimulation
• Other Study ID Numbers: SP-OCD

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No