The Effects of Repetitive Transcranial Magnetic Stimulation in Obese People With BED

The Effects of Repetitive Transcranial Magnetic Stimulation in Obese Females With Binge Eating Disorder: a Protocol for a Double-blinded, Randomized, Sham-controlled Trial.

The presence of binge eating (BE) is a core feature of bulimic syndromes. Binge eating disorder (BED) is a new category in DSM-5 highly associated with higher body mass index (BMI). The neural mechanisms that underlie BE are of great interest in order to improve treatment interventions. Brain mechanisms underlying drug and food craving are suggested to be similar. These mechanisms demonstrated hyperactivity in the orbitofrontal and anterior cingulate cortex and lack of regulatory influence from lateral prefrontal circuits. Several novel studies began to assess the potential benefits of brain stimulation in reducing craving and associated addictive behaviors with promising results. Previous findings testing a one-off session of repetitive transcranial magnetic stimulation (rTMS) in healthy women identified as strong cravers and individuals with bulimia nervosa or bulimic-type eating disorders reported reduction of food craving and BE, providing evidence to support a broader and deeper investigation of the benefits associated with rTMS. Importantly, the use of brain imaging studies contributes to the understanding of psychiatric disorders and underlying mechanisms being target by the rTMS intervention.

Objectives: The primary aim is to investigate the effects of rTMS over BE frequency. Secondary aims include the evaluation of the effects of rTMS on food craving, body weight, brain activity, cognition, general psychopathology, hormonal regulation and neurobiological markers. Methods: Sixty obese females with BED will be randomized to receive 20 sessions of rTMS (n=30) or placebo (n=30) scattered 3 days/week.

Expected Results: Primarily it is expected that rTMS intervention will decrease BE frequency. Consequently, body weight will be reduced. It is also expected that food craving be decreased, cognitive performance be enhanced, and neurobiological markers be improved.

The primary aim is to investigate the effects of rTMS over BE frequency. Secondary aims include the evaluation of the effects of rTMS on food craving, body weight, brain activity, cognition, general psychopathology, hormonal regulation and neurobiological markers. Methods: Sixty obese females with BED will be randomized to receive 20 sessions of rTMS (n=30) or placebo (n=30) scattered 3 days/week.

Expected Results: Primarily it is expected that rTMS intervention will decrease BE frequency. Consequently, body weight will be reduced. It is also expected that food craving be decreased, cognitive performance be enhanced, and neurobiological markers be improved.

Inclusion Criteria:

• 18 to 55 years old
• Right handed
• Females
• BED diagnosis (EDE 16.0 - BED module) according to the DSM-5 criteria
• BMI ≥ 35kg/m2 and body weight ≤ 150kg
• Ability to write, read, and understand all elements of the study
• Safety laboratory blood work (fasting glucose, fasting glucose/insulin ratio, CBC, and TSH) within normal range
• Informed consent signed.

Exclusion Criteria:

• Past history of head or eye injury or epilepsy
• Body metallic implants, pacemaker, claustrophobia and any other contraindication to fMRI or rTMS;
• Current use of psychotropic drugs (except for antidepressants on a stable dose for at least one month)
• Current use of any anti-obesity drug (three months washout period for any other medication)
• Pregnancy or breastfeeding
• Diabetes Mellitus diagnosis
• Major psychiatric disorder requiring immediate treatment
• Substance dependence (SCID-I/P module for substance abuse and/or dependence applied for those who disclose substance use at checklist, following the DSM-5 criteria)
• Individuals currently receiving any psychological therapy for their eating disorder
• Cushing's and Turner's syndrome.