Lifetime history of depression and eating behaviours: a co-twin control study of the TwinsUK registry

The extent to which depression impacts eating behaviours, and the mechanisms underpinning their relationship are unclear. We aim to investigate the relationship between depression diagnosis and eating behaviours.

We analysed data from 1426 participants of the twins UK registry, which includes 722 monozygotic (MZ) and 702 dizygotic (DZ) twins. Eating behaviours were measured using the three-factor eating questionnaire while depression and antidepressant usage were self-reported. Co-twin control design was used to model the association between depression and eating. Sensitivity tests were implemented to exclude those using antidepressants.

The heritability estimates for eating behaviours were between 35 and 41 %. Twins with a history of depression had higher scores on the emotional (d = -0.31) and constrained eating (d = -0.18). The intraclass correlations revealed a higher covariation in MZ compared to DZ twins. A moderate relationship was observed between lifetime depression and uncontrolled (β = 0.61, 95 % CI [0.17; 1.06]), emotional (β = 0.38, 95 % CI [0.22; 0.55]) and restrained eating (β = 0.43, 95 % CI [0.10; 0.77]). After removing those on antidepressants (n = 195), the relationship between eating and depression attenuated, indicating a potential influence of antidepressants in this association.

Our findings suggest the association between depression and eating can be partly explained by pre-existing genetic and environmental vulnerabilities. Understanding the mechanisms underlying this relationship could guide the development of effective management strategies, including personalized nutrition plans, integrated mental and dietary care, and regular monitoring to mitigate the risk of maladaptive eating behaviours and eating disorders.