Deep Transcranial Magnetic Stimulation (dTMS) of the Medial Prefrontal Cortex in Food Addiction and Obesity

Deep Transcranial Magnetic Stimulation (dTMS) of the Medial Prefrontal Cortex (mPFC) in Food Addiction and Obesity

This experiment is based on a unique technique of deep Transcranial magnetic stimulation (dTMS) of the brain's cortex, aiming to produce weight loss in food-addicted severely obese adults.

The neurobiological underpinnings of food addiction in obesity point to chemical, structural and functional imbalance in the mesolimbic dopaminergic brain system. This may cause symptoms of altered reward processing, excessive cravings for hyperpalatable food and repeated self-regulation failures to control food intake in this population. Specifically, the medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC) and deeper reward-related brain regions function differentially from healthy controls and similarly to individuals with substance or behavioral addiction. Deep transcranial magnetic stimulation of the mPFC has been shown efficacious in reducing cravings and other addictive symptoms in individuals with SUD, as well as symptoms of compulsivity in obsessive compulsive disorder (OCD). In this study the investigators use deep transcranial magnetic stimulation (dTMS) with an H-coil to safely stimulate the mPFC and deeper brain regions, in individuals with obesity and food addiction. The investigators aim to produce neuroplasticity favoring the restoration of mPFC functioning, alleviating food addiction symptoms and promoting weight loss.

Inclusion Criteria:

• 30 ≤ BMI ≥ 50.
• Having had at least one prior conventional weight loss attempt, but no current weight loss attempts or over the last 3 months.
• Having satisfied a safety screening questionnaire for TMS (Keel, 2001)
• Omnivorous
• Have not had experience with TMS of any kind
• Exclusion Criteria:
• They experience tremor in any limb.
• They experience seizures.
• They have a history of epilepsy or seizure (EXCEPT those therapeutically induced by ECT, or febrile childhood seizures).
• They are at increased risk for seizures for any reason, including prior diagnosis of increased intracranial pressure (such as after large infarctions or trauma), or a history of significant head trauma with loss of consciousness for > 5 minutes.
• A history of clinically significant neurological disorders, including organic brain disease, epilepsy, stroke, brain lesions, multiple sclerosis, previous neurosurgery or personal history of head trauma that resulted in loss of consciousness for > 5 minutes and retrograde amnesia for > 30 minutes (self-reported history).
• They have a clinically significant hearing impairment, unless a medical letter is provided permitting the participant to receive a dTMS treatment.
• The participant has an unstable physical disease, such as acute unstable cardiac disease, or high blood pressure (>150 mmHg, systolic/> 110 mmHg diastolic, unless a medical letter is provided permitting the participant to receive a dTMS treatment.

Exclusion criteria:

• They experience tremor in any limb.
• They experience seizures.
• They have a history of epilepsy or seizure (EXCEPT those therapeutically induced by ECT, or febrile childhood seizures).
• They are at increased risk for seizures for any reason, including prior diagnosis of increased intracranial pressure (such as after large infarctions or trauma), or a history of significant head trauma with loss of consciousness for > 5 minutes.
• A history of clinically significant neurological disorders, including organic brain disease, epilepsy, stroke, brain lesions, multiple sclerosis, previous neurosurgery or personal history of head trauma that resulted in loss of consciousness for > 5 minutes and retrograde amnesia for > 30 minutes (self-reported history).
• They have a clinically significant hearing impairment, unless a medical letter is provided permitting the participant to receive a dTMS treatment.
• The participant has an unstable physical disease, such as acute unstable cardiac disease, or high blood pressure (>150 mmHg, systolic/> 110 mmHg diastolic, unless a medical letter is provided permitting the participant to receive a dTMS treatment.
• The participant is at a high risk for severe violence or suicidal tendencies, has current DSM5 diagnosis of schizophrenia, bipolar disorder, or other psychotic disorder, as reported during the screening interview (see appendix 3).
• The participant has metallic particles in the eye, implanted cardiac pacemaker or any intracardiac lines, implanted neuro-stimulators, intracranial implant (e.g., aneurysm clips, shunts, stimulators, cochlear implants, or electrodes) or implanted medical pumps.
• The participant is having, or has had, any metal in the head (outside the mouth).
• The participant has any cognitive or functional disability, according to criteria specified in the DSM-V, such as active and unstable psychiatric disorder according to DSM-V (Axis I and Axis II), diagnosed within the last year.
• The participant has started or changed a psychotropic prescription within the past three months.
• The participant has current alcohol or other substance abuse or dependence, or has had one over the past 12 months prior to recruitment.
• The participant can't reliably communicate with the investigator, or is unlikely to cope with the requirements of the experiment.
• The participant is having a known or suspected pregnancy or lactation.
• The motor threshold can't be found or quantified.
• The PI decides that the participant should be withdrawn from the study for the safety and welfare of the participant. For example, the participant experiences adverse event which is contraindicated with the continuation in the study.
• The participant has a history of intolerance to a TMS treatment. The participant asks for withdrawal.