This is a pilot study to examine the tolerability, safety and early efficacy of two forms of transcranial magnetic stimulation (TMS) for treating adolescents with Obsessive Compulsive Disorder (OCD) who have experienced limited improvements with usual treatments for OCD in adolescents.

The project's primary goal is to examine whether adolescents can complete 3 consecutive weeks of TMS administered 5 days per week, and to describe the type of and how common individual side effects with TMS occur in adolescents with OCD.

Participants will:

• visit the clinic every weekday for 3 weeks (15 days) to receive TMS treatments
• have a brain MRI scan before TMS treatments begins and after finishing all TMS
• complete questionnaires and report changes in behavior and physical symptoms

This study's primary goal is to examine whether treatment with two forms of transcranial magnetic stimulation (TMS) called theta burst stimulation (TBS) show acceptable tolerability, safety, and preliminary signals of efficacy for adolescents with Obsessive Compulsive Disorder (OCD) that has not responded satisfactorily to 1st line treatments. While TMS is FDA-approved for OCD in adults, data on TMS in youth with OCD is limited. Results will inform on how suitable TMS treatment is for adolescents with OCD, and guide future, larger studies.

The study is considered a randomized, single blind, clinical trial.

The design of the study is a two-group parallel comparative study of two different TMS stimulation sites, the orbito-frontal cortex (OFC) and the dorsal medial prefrontal cortex (dmPFC).

Model description: both groups will receive active TMS treatment sessions in clinic every weekday for 3 consecutive weeks (15 days). During each TMS session, participants in both groups will receive 3 TMS stimulations separated by a rest period, for a total of 45 individual TMS treatments. Study participants will receive TMS to only their assigned stimulation site.

Number of arms: there are two treatment arms based on assigned treatment site, an OFC arm and a dmPFC arm.

Masking: an independent evaluator will be masked to treatment arm assignment and adverse events. All other study personnel will not be masked.

Allocation: participants will be randomly assigned to group according to a computer-generated assignment schedule.

Enrollment: total planned enrollment is 30 eligible participants who are randomized.

Arm Information:

Arm titles-- orbitofrontal cortex (OFC) and dorsal medial prefrontal cortex (dmPFC) Arm types: the dmPFC arm is considered the intervention arm; the OFC arm is considered the active comparator arm.

Interventions:

Intervention type: Device (both arms)

Intervention name(s):

OFC - continuous theta burst stimulation (cTBS) dmPFC - intermittent theta burst stimulation (iTBS)

Intervention description:

OFC - three stimulations per day of 1,800 pulses/stimulation cTBS for 15 days dmPFC - three stimulations per day of 1,800 pulses/session iTBS for 15 days

Inclusion Criteria:

1. outpatients
2. ages 13 - 17 years
3. meets current DSM-5 criteria for Obsessive Compulsive Disorder with screening CY-BOCS II score > 16 (moderate to severe).
4. stable on chronic psychotropic medications and/or therapy for 8 weeks prior to the study and agreeable to continue throughout the study without changes.
5. participants may continue to take medications and record daily usage throughout the study.
6. capacity to provide informed assent and parent or legal guardian able to provide consent.
7. ability to tolerate clinical study procedures.
8. successfully complete the screening forms without any contraindications.

Exclusion Criteria:

1. Psychiatric: history of schizophrenia, bipolar disorder, substance/alcohol abuse disorder, current elevated suicide risk, prior psychosurgery, prior ECT.
2. Neurologic: severe neurocognitive disorder, seizure disorder, certain structural brain lesions (e.g., intracranial mass lesions, hydrocephalus, sequelae of meningitis, frank brain injury).
3. TMS contraindications: implanted device; presence of metal in the head, including eyes and ears (excluding dental implants); certain tics; medications or systemic illness that predispose seizure risk; family history of 1st degree relative with seizure disorder.
4. Subjects with an unstable physical, systemic, or metabolic disorder (e.g., unstable hypertension, malnutrition secondary to eating disorder).
5. Females who are pregnant or nursing (as determined by a questionnaire and pregnancy test).
6. Current and anticipated continued treatment with excluded medication (See prohibited list).
7. Inability to complete the research protocol as determined by the Principal Investigator.

IPD to be shared will include both primary endpoint data and secondary endpoint data.

Beginning one year and ending 3 years after publication of results

Qualified researchers who submit a brief description of planned analyses must be submitted to the PI to review and approve data sharing