Non-invasive brain stimulation for food cravings, consumption, and disorders of eating: A review of methods, findings and controversies

Objective: To describe the state of the human research literature pertaining to the use of non-invasive brain stimulation (NIBS) procedures for modulating food cravings, food consumption, and treating disorders of eating (i.e., obesity, bulimia nervosa, and anorexia nervosa). Methods: A narrative review of methods, empirical findings, and current areas of controversy. Both single session experimental and multi-session therapeutic modalities are considered, separately for repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) technologies. Results: Single-session studies involving NIBS report more consistent effects of rTMS than tDCS, but this advantage is more clear in relation to food cravings than actual food consumption. Multisession therapeutic approaches have been applied to both obesity and eating disorders. With respect to obesity, the three published (tDCS) and one ongoing trial (rTMS) have yielded promising though very preliminary findings. Application of multi-session NIBS (predominantly rTMS) to eating disorders has also yielded promising but ultimately inconclusive results, both in relation to bulimia nervosa and binge eating disorder. Findings regarding excitatory NIBS in the context of anorexia are more controversial, with evidence of improvement in affective functioning, but a trend of iatrogenic weight loss. Conclusions: Excitatory NIBS-particularly rTMS-can reliably reduce food cravings in single and multi-session format. For multi-session treatment of clinical conditions, more studies are needed for both rTMS and tDCS, particularly in relation to obesity, bulimia, and binge eating disorder. Application of NIBS for anorexia is less clear at this point, and excitatory NIBS may be contraindicated on theoretical and empirical grounds. (C) 2017 Elsevier Ltd. All rights reserved.