Neuropsychological and metabolic interconnectivity in obesity, anorexia and bulimia nervosa - an integrative literature review.

Abstract

A dysfunctional bi-directional signalling of plural neural networks expresses distinct metabolic disruption with mental health consequences in obesity, anorexia nervosa and bulimia nervosa. Maladaptive brain-gut connectivities lead to multifactorial contributing factors raising the interest of researchers in an effort to address their neurobiological, psychological and metabolic factors to improved mental health outcomes. The first aim of this review was to collate clinical evidence on brainstem-hypothalamus pathways in obesity, anorexia nervosa and bulimia nervosa. Further, it sought to describe the chief brain-based interactions within both the brain-gut and brain-gut-adipose axis in these conditions. Another aim was to explore the interactions of prominent peptides within the brain-gut and brain-gut-adipose axes. The final aim was to integrate the knowledge of maladaptive neural, peptide and hormonal signalling interactions with the mental faculty. According to integrative review guidelines, the multileveled information was grouped into three superordinate themes: the brain neurofeedback, the stomach neurofeedback and the sympathoadrenal neurofeedback, with seven subordinate themes: brain stem, lateral nucleus of the hypothalamus, arcuate nucleus of the hypothalamus, mechanism of appetite regulation, short-term satiety and long-term satiety signalling as well as the mechanisms of glucoprivation and lipoprivation, presented in Table 1. Their interconnectivites are synthesised in seven Figures, presented at each subtheme section. This paper augmented our understanding of brain maladaptive interactions with gut peptides and hormones among people with obesity and eating disorders and may serve a roadmap to neurobiological and metabolic influences on physical and mental health. Limitations identify qualitative areas of research towards evidence-informed psychiatric and health counselling support.