tDCS for Impulsivity and Compulsivity in Obesity

Minneapolis Veterans Affairs Medical Center31 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Interventions

Device: Active Transcranial Direct Current Stimulation (tDCS) coupled with cognitive trainingDEVICE

Cognitive training concurrent with 2 milliamperes (mAmps) of anodal stimulation applied to the right prefrontal cortex for total of 26 minutes.

Device: Sham Transcranial Direct Current Stimulation (tDCS) coupled with cognitive trainingDEVICE

Cognitive training concurrent with sham tDCS (30 secs ramp up/ramp down of current at beginning of session).

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

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.)

Outcomes

Primary Outcomes

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.

Time frame: 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.

Time frame: 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.

Time frame: 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.

Time frame: Change between baseline and 4 months post-stimulation (i.e., timepoint 8, final visit)

Secondary Outcomes

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.

Time frame: 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.

Time frame: Baseline visit