The paradoxical moderating effects of metacognition in the relationships between self-esteem, depressive symptoms, and quality of life in anorexia and bulimia.

BACKGROUND: Self-esteem and depressive symptoms contribute to a lower quality of life in people suffering from eating disorders. However, limited research has examined whether other factors may affect how these variables influence one another over time. Metacognition is a previously unexplored determinant that may impact the relationships between self-esteem, depressive symptoms, and quality of life in instances of eating disorders. AIM: This study sought to examine metacognitive self-reflectivity and mastery as moderators of the relationships between self-esteem, depressive symptoms, and quality of life and to determine if these relationships are different in people with anorexia compared with people with bulimia. METHODS: Participants with anorexia (n=40) and bulimia (n=40) were recruited from outpatient clinics. The participants were assessed on their metacognitive ability and self-reported on measures to assess their depressive symptoms, self-esteem, and quality of life. RESULTS: The results indicate that metacognitive self-reflectivity moderates the relationship between self-esteem, depressive symptoms, and quality of life in people with anorexia such that when self-reflectivity is high, lower self-esteem and higher depressive symptoms are associated with a lower quality of life. These relationships did not appear to be significant when self-reflectivity was low. In contrast, in the anorexia and bulimia groups, metacognitive mastery appeared to moderate the relationships between self-esteem, depressive symptoms, and quality of life such that when mastery was low, lower self-esteem and higher depressive symptoms were associated with a lower quality of life. These relationships did not appear significant when mastery was high. CONCLUSION: Metacognitive self-reflectivity and mastery seem to play paradoxical moderating roles in the relationships between self-esteem, depressive symptoms, and quality of life in people with anorexia and bulimia. These findings pave the way toward further research and have important clinical implications.

Alterations of the Composition and Neurometabolic Profile of Human Gut Microbiota in Major Depressive Disorder.

Major depressive disorder (MDD) is among the most prevalent mental disorders worldwide. Factors causing the pathogenesis of MDD include gut microbiota (GM), which interacts with the host through the gut-brain axis. In previous studies of GM in MDD patients, 16S rRNA sequencing was used, which provided information about composition but not about function. In our study, we analyzed whole metagenome sequencing data to assess changes in both the composition and functional profile of GM. We looked at the GM of 36 MDD patients, compared with that of 38 healthy volunteers. Comparative taxonomic analysis showed decreased abundances of Faecalibacterium prausnitzii, Roseburia hominis, and Roseburia intestinalis, and elevated abundances of Escherichia coli and Ruthenibacterium lactatiformans in the GM of MDD patients. We observed decreased levels of bacterial genes encoding key enzymes involved in the production of arginine, asparagine, glutamate, glutamine, melatonin, acetic, butyric and conjugated linoleic acids, and spermidine in MDD patients. These genes produced signature pairs with Faecalibacterium prausntizii and correlated with decreased levels of this species in the GM of MDD patients. These results show the potential impact of the identified biomarker bacteria and their metabolites on the pathogenesis of MDD, and should be confirmed in future metabolomic studies.