A Feasibility Study of Mindfulness Training Transcranial Direct Current Stimulation (tDCS) in Adults With Overweight and Obesity

King's College London52 enrolled

Overview

This study will investigate the feasibility of combining an app-based Mindfulness training (MT) with at-home administered transcranial direct current stimulation (tDCS) in adults with overweight or obesity and assess whether MT with tDCS may improve weight-related behaviours in this population. Specifically, the study will assess whether MT+ active tDCS, as opposed to MT+ sham tDCS or waiting list control, reduces high calorie food craving and consumption. Findings will inform the development of a future large-scale randomised controlled trial. The trial will be conducted in the UK.

A randomised controlled feasibility trial with three parallel arms: \[MT + real tDCS\] vs \[MT + sham tDCS\] vs \[Waiting list control group\].

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Enrollment

Conditions

Adults With Overweight and Obesity

Interventions

The MT is an established app-based programme delivered by Headspace®. During MT, participants complete guided meditation sessions which focus on mindful eating and on coping with cravings. Each MT session lasts 15 min. Participants in the MT+ real tDCS and MT+ sham tDCS groups will be given instructions to practice daily mindfulness for 3 weeks. During 10 of these sessions, MT and real/sham tDCS will be delivered concurrently. TDCS: During tDCS, a constant weak direct current is applied via electrodes (anode and cathode) placed on the scalp. In this study, the anode will be placed over the right dorsolateral prefrontal cortex (dlPFC) and the cathode will be placed over the left dlPFC. In the real tDCS condition, stimulation will be delivered at a constant current of 2 mA with a 10 second fade in/fade out for 20 minutes. In sham tDCS, the stimulator will deliver 60 seconds of active stimulation at the start ("ramping up") and end ("ramping down") of the 20 minute period.

Eligibility

Sex: FEMALEMin age: 18 YearsMax age: 60 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Adults aged 18 to 60 w * Overweight or obese (BMI ≥25 kg/ m2) according to World Health Organisation (WHO) criteria. * Use and understand English as a language for everyday conversation. * Have access to a laptop or desktop computer with webcam and to able to attend baseline, post intervention and follow up assessments in the Institute of Psychiatry, Psychology and Neuroscience (KCL). Exclusion Criteria: * Insufficient written and spoken English * All known contraindications to tDCS (Brunoni et al., 2012) * Pregnancy; history of neurological disease and/or seizure * Having any metallic implants in the head or body * History of head or eye injury * Significant health problems in the previous six months * A lifetime diagnosis of substance dependence, psychosis, bipolar disorder, borderline personality disorder; any other primary psychiatric disorder requiring treatment in its own right * Taking psychotropic medication * Taking medication for weight loss Regular, current or past, mindfulness meditation or yoga practice (defined as \> 20 minutes, twice or more per week during the past 2 months) * Consuming more than 14 units of alcohol per week who are unwilling to reduce their alcohol intake for the duration of the treatment * Current illicit drug use * Learning difficulties that would preclude safe tDCS self-administration and/or completion of questionnaire measures and neurocognitive tasks (e.g.; working memory and inhibitory control) * Current atypical anorexia nervosa or purging once a week or more.

Outcomes

Primary Outcomes

The feasibility of combining an app-based Mindfulness training (MT) with at-home Administered transcranial direct current stimulation (tDCS) by assessing intervention adherence

By assessing the tDCS session completed and the number of the MT sessions completed will be tracked through the app across the full 8 weeks

Time frame: post treatment assessment (assessed at week 3 post start of treatment)

The feasibility of combining an app-based Mindfulness training (MT) with at-home Administered transcranial direct current stimulation (tDCS) by assessing intervention recruitment rate

Recruitment rate/month over months will be assessed to demonstrate that recruitment targets for the main trial can be met within an adequate time-frame.

Time frame: post treatment assessment (assessed at week 3 post start of treatment)

The feasibility of combining an app-based Mindfulness training (MT) with at-home Administered transcranial direct current stimulation (tDCS) by assessing intervention retention rates

determine retention rates from randomization through intervention completion

Time frame: post treatment assessment (assessed at week 3 post start of treatment) and at follow up (assessed at week 8 post start of treatment)

Participant views about treatment acceptability

Treatment Acceptability Questionnaire: asking participants to indicate if MT with self-administered tDCS is an acceptable approach to treatment and whether they would recommend MT + tDCS to a friend if they were struggling with their weight.

Time frame: post treatment assessment (assessed at week 3 post start of treatment)

Secondary Outcomes

Change in high calorie food intake in the lab

Taste Test: actual food consumption will be measured by means of a bogus "taste test". Consumption will be determined by weighing the food before and after the "taste test" and the difference in weight from pre- to post-assessment will be converted into calories and used as a measure of food intake.