Efficacy of neurofeedback vs. mental imagery for subclinical binge eating is differentially affected by impulsivity

Abstract

Background: Impulsivity is known to reduce the efficacy of interventions for dysfunctional eating behaviours. However, this relationship may depend on the specific type of treatment applied. The present study examined the relationship between impulsivity and treatment efficacy in two interventions against subclinical binge eating: neurofeedback and mental imagery. Neurofeedback is frequently and successfully used to treat disorders related to impulsivity. We thus hypothesised that neurofeedback would be more suitable for the treatment of impulsive individuals, showing less negative impact on treatment efficacy by impulsivity than a mental imagery treatment. Methods: Female restrained eaters (n=50) with regular episodes of subclinical binge eating were randomised to one of two treatments, applying either neurofeedback or mental imagery (n=25 each) after food cue exposure. Impulsivity was assessed at pre-treatment and its relationship with treatment efficacy (reductions in binge eating to a three months follow-up) was analysed. Type of treatment served as a moderator. Findings: There was a significant interaction between treatment type and impulsivity (t = -2.72, p = .009), with a negative effect of impulsivity on treatment efficacy in mental imagery (b = -0.26, p = .022), but not in neurofeedback (b = 0.17, p = .141). Discussion: For neurofeedback, impulsivity did not affect treatment efficacy, whereas outcomes in mental imagery were influenced by this trait. For eating-related health interventions, we thus recommend to assess impulsivity prior to interventions, as it may help to choose a suitable treatment and assure sufficient treatment success and health behaviour improvement in impulsive individuals.