Disinhibited eating (DE) behaviors - such as overeating or binge eating - are common dysfunctional behaviors, especially in female populations. These behaviors can contribute to developments of overweight or obesity, and associated negative health consequences, like non-communicable diseases or eating disorders. Still, treatments for DE show moderate efficacy and may benefit from improvements. Recently, experts called for more research on brain-directed treatments to target DE and related eating disorders. Neurofeedback (NFB), using electroencephalographic (EEG) activity, is a well-established and safe neuromodulatory approach, based on an acquisition and online feedback of EEG-signals. It enables patients to regulate brain activity associated with dysfunctional psychological states or behaviors. However, EEG NFB had - to date - not been evaluated for the treatment of DE.
The present doctoral thesis reports on the development and evaluation of an EEG NFB protocol for the treatment of DE. The protocol is based on a synthesis of current theories on the etiology of DE, empirical findings regarding associated psychophysiological activity, and adaptable treatment components. It consists of ten sessions and incorporates self-regulation of tense physiological arousal, marked by EEG high beta activity, after exposure with personalized food cues.
Two randomized controlled trials and an experimental EEG study aimed at the evaluation of the general and specific treatment efficacy, as well as treatment mechanisms of the NFB. The studies were conducted in subclinical samples of female restrained eaters with DE.
Study 1 (initial sample: n = 34) compared a NFB group to a waitlist group and yielded evidence for the general efficacy of the NFB in reducing DE episodes. Results remained stable to a three-month follow-up. Further, the new NFB was well-accepted by the participants.
In Study 2 (initial sample: n = 75), NFB and an additional intervention with a highly comparable treatment (mental imagery) were compared to a waitlist condition. NFB, but not the alternative intervention, resulted in significant post-treatment reductions of DE episodes compared to the waitlist. Results remained stable to a three-month follow-up and indicated specific efficacy of the NFB approach.
Study 3 (n = 36) aimed at an evaluation of relevant treatment mechanisms in NFB. The experimental study compared the presence and influence of physiological learning (regulation of EEG high beta activity) and psychological learning (enhanced somatic self-efficacy) in the NFB and control intervention group. Analyses showed that physiological learning was only present in the NFB group and showed stronger relations to treatment outcomes than somatic self-efficacy. According to these results, physiological learning constitutes a relevant treatment mechanism in the developed NFB protocol.
In summary, the developed NFB could be evaluated as an efficacious and physiologically-based treatment approach for the treatment of DE. It may be a beneficial adjunct for treatments of eating disorders (e.g., binge eating disorder). Based on the results of this dissertation project, replications in clinical groups are now warranted. Additional implications for research and practice are discussed.