tDCS for Impulsivity and Compulsivity in Obesity

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

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), PHQ-9 Depression Screen, and 4 domains of the NIH Examiner Battery. Weight will be tracked throughout the study. MN-BEST blast exposure screening tool is also conducted at baseline.

Impulsive Behavior, Behavior Control, Appetitive Behavior, Health Risk Behaviors, Compulsive Behavior

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).

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.

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

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

Differences in magnitude of changes in Flanker scores (numeric summary scores) between active tDCS-cognitive training and sham-cognitive training groups from baseline to follow-up sessions

Differences in magnitude of changes in Set Shifting scores (numeric summary scores) between active tDCS-cognitive training and sham-cognitive training groups from baseline to follow-up sessions

Differences in magnitude of changes in Dot Counting scores (numeric summary scores) between active tDCS-cognitive training and sham-cognitive training groups from baseline to follow-up sessions

Differences in magnitude of changes in Unstructured Planning Task scores (numeric summary scores) between active tDCS-cognitive training and sham-cognitive training groups from baseline to follow-up sessions

Differences in magnitude of changes in weight (pounds) between active tDCS-cognitive training and sham-cognitive training groups from baseline to end of study

Effect of traumatic brain injury history at baseline (none, single, multiple prior episodes), as measured with Minnesota Blast Exposure Screening Tool (MN-BEST), on differences in magnitude of changes in Binge Eating Scale Scores (numeric summary score) between active tDCS-cognitive training and sham-cognitive training groups from baseline to end of study

Effect of traumatic brain injury history at baseline (none, single, multiple prior episodes), as measured with Minnesota Blast Exposure Screening Tool (MN-BEST), on differences in magnitude of changes in Flanker scores between active tDCS-cognitive training and sham-cognitive training groups from baseline to end of study

Effect of history of traumatic brain injury on impulsive and compulsive eating behavior-NIH Set Shifting

Effect of traumatic brain injury history at baseline (none, single, multiple prior episodes), as measured with Minnesota Blast Exposure Screening Tool (MN-BEST) , on differences in magnitude of changes on Set Shifting scores between active tDCS-cognitive training and sham-cognitive training groups from baseline to end of study

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.)