Despite the considerable number of studies that have assessed evidence for a longitudinal relationship between eating pathology and depression, there is no clear consensus regarding whether they are uni- or bi-directionally related.
To undertake a meta-analysis to provide a quantitative synthesis of longitudinal studies that assessed the direction of effects between eating pathology and depression. A second aim was to use meta-regression to account for heterogeneity in terms of study-level effect modifiers.
Meta-analysis results on 30 eligible studies showed that eating pathology was a risk factor for depression (rm = 0.13, 95% CI: 0.09 to 0.17, P < 0.001), and that depression was a risk factor for eating pathology (rm = 0.16, 95% CI: 0.10 to 0.22, P < 0.001). Meta-regression analyses showed that these effects were significantly stronger for studies that operationalized eating pathology as an eating disorder diagnosis versus eating pathology symptoms (P < 0.05), and for studies that operationalized the respective outcome measure as a categorical variable (e.g., a diagnosis of a disorder or where symptoms were “present”/“absent”) versus a continuous measure (P < 0.01). Results also showed that in relation to eating pathology type, the effect of an eating disorder diagnosis (b = −0.06, t = −7.304, P ≤ 0.001) and bulimic symptoms (b = −0.006, t = −2.388, P < 0.05) on depression was significantly stronger for younger participants.
Eating pathology and depression are concurrent risk factors for each other, suggesting that future research would benefit from identifying factors that are etiological to the development of both constructs.
The authors have not supplied their declaration of competing interest.