The role of worry and rumination in eating disorders (EDs) is controversial. This meta-analysis of the literature is aimed at clarifying the relationship between repetitive negative thinking (RNT) and EDs. In accordance with the PRISMA criteria, a comprehensive search of the literature was conducted on PubMed and PsycInfo from inception to March 2021. Search terms: “eating disorder/anorexia/bulimia/binge eating disorder” AND “worry/rumination/brooding/repetitive thinking”. A manual search of reference lists was also run. Forty-three studies were included. RNT was found to be associated with anorexia, bulimia, and binge eating disorder. A moderating effect was found for “presence/absence ED diagnosis” and “subtype of ED symptom”. ED patients showed higher RNT than the general population. No differences were observed for age or between worry and rumination in the magnitude of their association with EDs.

Background Separation anxiety disorder (SAD) and separation anxiety symptoms (SA) have been studied both epidemiologically and genetically; however, large between‐studies discrepancies emerge relative to the role of genetic, shared‐, and nonshared environmental influences on these conditions. Methods Based upon available literature, 18 cohorts and 31,859 subjects belonging to twin samples in Europe, the United States, and Australia were included in three meta‐analytic estimations of: the standardized variance components of etiological influences on SAD/SA, and on the effect of sex and rater. Results Meta‐analytic estimations carried out on all cohorts showed that within‐family (genetic 43% and shared environmental 17%) factors explain most of individual differences for SAD/SA. Meta‐heritability estimates were higher among females (.52) than males (.26), whereas nonshared environmental effects were stronger for the latter (.74) than for the former (.41). When SAD/SA was rated by parents, the shared environmental influences were higher than those obtained with self‐assessment instruments (.23 versus .05), but this may reflect an age difference between subsamples. Conclusions A shared environmental effect is present and important in SAD/SA. Our results support at an etiological level the involvement of parents in treating SAD/SA in children, and the provision of specific strategies to parents to manage their own anxiety. Depression and Anxiety 00:1–8, 2012.