Gene-Environment Interplay Between Perceived Stress and ADHD Symptoms in Adults.

Objective: The association between perceived stress (PS) and ADHD symptoms in adulthood is well established, yet the underlying mechanisms remain unclear. This study employed a genetically informative design to investigate the roles of gene-environment (GE) correlation and gene-environment interaction (G × E) in explaining this association. Three G × E interaction models were considered: the diathesis-stress model, the bioecological model, and the differential sensitivity model.

Method: In total, 1,270 twins (mean age: 23.3 ± 2.4 years) participated in an online survey, which included ADHD symptoms and PS scales. The PS scale measured stress across five categories: Friendship Stress (FS), Family Conflicts (FC), Financial Difficulties (FD), Academic Stress (AS), and Future Career Concerns (FCC).

Results: Bivariate Cholesky model-fitting analyses revealed significant genetic correlations between ADHD symptoms and all five PS categories, indicating a pervasive influence of GE correlations on these associations. Further bivariate G × E model-fitting analyses showed that G × E interaction effects were not significant for FS or FC but were significant for FD, AS, and FCC. Specifically, the relationship between FD and ADHD symptoms aligned with the differential sensitivity model, where genetic variance was heightened at extreme levels of FD. The association between AS and ADHD symptoms followed the bioecological model, characterized by increased shared environmental variance at higher stress levels. Finally, the association between FCC and ADHD symptoms was consistent with the diathesis-stress model, where genetic influences amplified with increasing stress levels.

Conclusion: These findings underscore the complex interplay of genetic and environmental factors in the ADHD symptoms-PS relationship and suggest the importance of incorporating these mechanisms into intervention strategies for ADHD symptoms.