Emotional overeating and depression in the Sri Lankan Twin Register

Associations between depression and obesity are often reported in epidemiological studies. Emotional overeating (EOE), the tendency to increase food consumption in response to sadness and stress, has been suggested as a link... [ view full abstract ]

Associations between depression and obesity are often reported in epidemiological studies. Emotional overeating (EOE), the tendency to increase food consumption in response to sadness and stress, has been suggested as a link between depression and obesity. EOE therefore poses as a potential target for behavioural intervention in people with co-morbid depression and obesity.  However, the aetiology of EOE is poorly understood, especially in the context of depression in populations with high levels of obesity. This study investigated the genetic and environmental contributions to depression and EOE in a Sri-Lankan population, using genetic model-fitting analysis. 3561 twins and singletons in the Colombo Twin and Singleton Study-Phase 2 rated their EOE behaviour and depressive symptoms (Beck Depression Inventory). EOE and depression were significantly associated (r=0.16 Males, r=0.17 Females). A correlated factors twin model suggested distinct aetiology of EOE and depression between males and females. Heritability was higher for both EOE and depression in females (EOE h2=27%, 95% CI: 5-46%; depression h2= 26%, 95% CI: 2-48%) than males (EOE h2=14%, 95% CI: 0-42%; depression h2= 8%, 95% CI: 2-8%), while shared environmental factors were more important in males (EOE c2=19%, 95% CI: 1-43%; depression c2= 20%, 95% CI: 4-36%) than females (EOE c2=4%, 95% CI: 2-4%; depression c2= 14%, 95% CI: 14-15%). Unique environmental factors explained the majority of variance in EOE and depression in males and females. This is the first twin study to examine EOE and depression in a non-Western population. Our results suggested sex differences in the aetiology of EOE and depression. Behavioural intervention for comorbid depression and obesity might be a useful avenue to explore in males.  Our findings differ from results reported from Western population, highlighting the importance of cross-cultural comparisons in behavioural genetic research.