The shared and unique genetic relationship between mental well-being, depression and anxiety symptoms and cognitive...

Alterations to cognitive function are often reported with depression and anxiety symptoms, yet few studies have examined the same associations with mental well-being. This study examined the association between mental well-being, depression and anxiety symptoms and cognitive function in 1502 healthy adult monozygotic (MZ) and dizygotic (DZ) twins, and the shared/unique contribution of genetic (G) and environmental (E) variance. Using linear mixed models, mental well-being was positively associated (p < .01) with sustained attention (β = 0.127), inhibition (β = 0.096), cognitive flexibility (β = 0.149), motor coordination (β = 0.114) and working memory (β = 0.156), whereas depression and anxiety symptoms were associated (p < .01) with poorer sustained attention (β = -0.134), inhibition (β = -0.139), cognitive flexibility (β = -0.116) and executive function (β = -0.139). Bivariate twin modelling showed well-being shared a small environmental correlation with motor coordination and a small genetic correlation with working memory. Trivariate twin modelling showed well-being shared a small genetic correlation with inhibition, whereas depression and anxiety symptoms shared a small environmental correlation with inhibition. The remaining variance was mostly driven by unique G and/or E variance. Overall, well-being and depression and anxiety symptoms show both independent and shared relationships with cognitive functions but this is largely attributable to unique G or E variance and small shared G/E variance between pairs of variables.