tDCS for Impulsivity and Compulsivity in Obesity

Study Overview
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Brief Summary
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Even when they know it can improve health, many individuals with loss of control eating struggle when they are trying to make and sustain new health habits for weight loss and maintenance of weight loss. Impulsivity, characterized by lack of foresight and planning and excessive risk taking, and compulsivity, characterized by inability to break old habitual behaviors, may play a role in refractory obesity. The primary objective of this pilot study is to investigate the effect of a novel neuroplasticity based intervention, cognitive training coupled with transcranial direct current stimulation (tDCS), on measures of impulsivity and compulsivity in individuals with obesity.

Detailed Description
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Impulsivity and compulsivity are two psychological factors which contribute to addictive behaviors. Impulsivity is characterized by lack of foresight and planning, and excessive risk taking. Impulsivity is a characteristic of poor executive functioning, and reflects deficits in goal-oriented behavior and self-regulation. Compulsivity is characterized by inability to break old habits. Both of these traits may play a role in refractory obesity. Transcranial direct current stimulation (tDCS) coupled with cognitive training may strengthen key circuitry involved in impulse control within the prefrontal cortex. tDCS coupled with cognitive training has the potential to reduce impulsivity and compulsivity in individuals with obesity, with the potential for therapeutic application as a non-pharmacologic approach to management of food-related eating behaviors which may impact weight. For this double-blind, randomized, placebo (sham) controlled study pilot study the investigators aim to recruit and complete studies in approximately 20 individuals, randomly assigned to receive either active or sham tDCS, both coupled with computerized cognitive training tasks, for five days. Additionally, participants will attend follow up visits at approximately 2, and 4 months after the course of intervention visits is completed. Testing pre- and post-intervention will include the Binge Eating Scale (BES), Patient Health Questionnaire 9 (PHQ-9) Depression Screen, and 4 domains of the NIH Examiner Battery. Weight will be tracked throughout the study. The Minnesota Blast Exposure Screening Tool (MN-BEST) is also conducted at baseline.

Official Title
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Role of Transcranial Direct Current Stimulation to Decrease Impulsivity and Compulsivity in Individuals With Obesity

Conditions
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Obesity, Impulsivity, Compulsive Overeating

Intervention / Treatment
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* Device: Device: Active Transcranial Direct Current Stimulation (tDCS) coupled with cognitive training
* Device: Device: Sham Transcranial Direct Current Stimulation (tDCS) coupled with cognitive training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Obese (BMI>30) Adults ages 18 years or older receiving care through the Minneapolis VA Healthcare System Able to understand English, self-consent and follow study-related procedures Willing to use a reliable form of birth control if they are of females of child-bearing potential. Exclusion Criteria: History of any of the following issues: seizures, severe or moderate head injury, head surgery, significant neurological disorder(significance based on Principal Investigator's judgment), frequent severe headaches History of scalp conditions such as eczema or seborrheic dermatitis Metal in head (other than in mouth) including shrapnel/surgical clips/welding fragments Implanted medical devices (including pumps and cardiac pacemakers) Pregnancy Active substance abuse Psychological or medical disorders requiring inpatient treatment Presence of a known metabolic or hormonal disorder (such as Cushing's) which affects weight/appetite. (History of hypothyroidism is acceptable if subject is on treatment with normal thyroid stimulating hormone (TSH) and free thyroxine (FT4) on most recent check within the last 3 months and has been on stable dosage of l-thyroxine for at least 3 months, taking it as prescribed.)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The study is not a disease treatment study. It involves of an Non-Significant Risk (NSR) device coupled with a set of computerized cognitive tasks in a small group of participants with primary outcome of change in an NIH Examiner domain (Flanker).
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active tDCS with cognitive training<br>Participants will receive 5 sessions of cognitive training concurrent with transcranial direct current stimulation (anode over right frontal cortex, cathode over left frontal cortex; 2 mAmps for 26 minutes). | Device: Device: Active Transcranial Direct Current Stimulation (tDCS) coupled with cognitive training<br>* Cognitive training concurrent with 2 milliamperes (mAmps) of anodal stimulation applied to the right prefrontal cortex for total of 26 minutes.<br>|
| Sham Comparator: Sham tDCS with cognitive training<br>Participants will receive 5 sessions of cognitive training concurrent with sham tDCS. For sham tDCS, electrodes are placed at the same locations as for active tDCS, but current is ramped up for the initial 30 secs, then immediately ramped back down. This method mimics the initial physical sensation of stimulation, but there is no active current for the remainder of the session. | Device: Device: Sham Transcranial Direct Current Stimulation (tDCS) coupled with cognitive training<br>* Cognitive training concurrent with sham tDCS (30 secs ramp up/ramp down of current at beginning of session).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in NIH Examiner Flanker Task Reaction Time | Differences in change in Flanker Task reaction time (score at final follow-up visit minus score at baseline) between active tDCS-cognitive training and sham-cognitive training groups. NIH Flanker absolute value range: 0 to 5 seconds. Higher values represent a better outcome. In the Flanker Task, a participant is instructed to press a key in response to viewing a stimulus presented on-screen. The Reaction Time, or the amount of time in seconds between presentation of the stimulus and the response, is measured. | Change between baseline and 4 months post-stimulation (timepoint 8/final visit) | 
| Change in NIH Examiner Set Shifting Task Score | Difference in change in Set Shifting Task scores (score at final visit minus baseline score) between active tDCS-cognitive training and sham- Higher values represent a better outcome. Set Shifting Scale absolute value range: Minimum -10, Maximum 10. The Set Shifting Task Score is a combination of two subscores for reaction time and accuracy on the task. | Change between baseline and 4 months post-stimulation (timepoint 8, final visit) | 
| Change in NIH Examiner Dot Counting Task Score | Differences in change in NIH Examiner Dot Counting Task scores (i.e., score at final visit minus baseline score) between active tDCS-cognitive training and sham-cognitive training groups. The change in score is equal to the score taken at the final follow-up visit minus the score taken at baseline. NIH Dot Counting absolute value range: numerical value -27 to +27. Higher values represent a better outcome. The Dot Count Task Score is the total sum of points awarded for dots a participant counts on the screen. The total score is a sum of scores for 27 individual trials. | Change between baseline and 4 months post-stimulation (i.e., timepoint 8/final visit) | 
| Change in NIH Examiner Unstructured Planning Task Score | Differences in change in NIH Examiner Unstructured Planning Task scores (i.e., score at final visit minus baseline score) between active tDCS-cognitive training and sham-cognitive training groups. The change in score is equal to the score taken at the final follow-up visit minus the score taken at baseline. Higher values represent a better outcome. The Unstructured Task Score is a numeric summary score that is equal to the total sum of points awarded for completed puzzle items. The total absolute score is a sum of scores for 3 individual trials, Absolute score range :-1469 to +1469. | Change between baseline and 4 months post-stimulation (i.e., timepoint 8, final visit) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Weight | Difference in change in weight (pounds) between active tDCS-cognitive training and sham-cognitive training groups (i.e., end of study weight minus baseline weight). A more negative score indicates a better outcome. | Change between baseline and 4 months post-intervention (i.e., timepoint 8/final visit) | 
| Effect of History of Traumatic Brain Injury on Impulsive and Compulsive Eating Behavior | Effect of history of a traumatic brain injury (TBI) on impulsive/compulsive eating behavior. A status of either TBI+ (positive for history of TBI) or TBI- (negative for history of TBI) was determined at the baseline visit with the Minnesota Blast Exposure Screening Tool. Impulsive/compulsive eating behavior was defined as the score on the Binge Eating Scale (BES) taken at the baseline visit. Scale range = 0-48. Lower scores indicate less impulsive/compulsive eating behavior (i.e., a better outcome). Calculation details: Average BES scores taken at baseline for TBI-positive participants and TBI-negative participants. | Baseline visit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Impulsive Behavior, Behavior Control, Appetitive Behavior, Health Risk Behaviors, Compulsive Behavior