Polygenic scores, which summarize an individual's genetic risk for a given trait, have become essential tools in investigating the relationship between genetic predisposition and psychiatric disorders.
A recent cross-sectional study published in JAMA Psychiatry sought to determine whether Polygenic scores (PGSs) for psychiatric traits are associated with all symptoms of psychiatric disorders or specific subsets and whether PGSs are linked to comorbid phenotypes via specific symptoms.
The study analyzed data from two population-based cohorts in the UK: the Avon Longitudinal Study of Parents and Children (ALSPAC; n=5,521) and the Twins Early Development Study (TEDS; n=4,625). By combining psychological network and PGS approaches, the study found that PGSs were primarily associated with a restricted set of trait-relevant symptoms. For example, PGSs for attention-deficit/hyperactivity disorder (ADHD) were linked to being easily distracted (correlation coefficient, r = 0.07), while the PGS for body mass index (BMI) was associated with symptoms such as being bullied (r = 0.053) and impaired decision-making (r = 0.041).
The findings suggest that PGSs are not uniformly associated with all symptoms of a disorder but are more closely tied to core symptoms. The researchers propose that shifting from a disorder-level to a symptom-level perspective may enhance investigations into the development and comorbidity of psychopathology by focusing on individual transdiagnostic symptoms. The authors concluded that a symptom-level approach may provide more detailed insights into the role of polygenic risk in psychopathology and comorbidity.
However, the study's cross-sectional design precludes causal inferences, and the findings need to be replicated in more diverse samples. Despite these limitations, the study highlights the importance of considering symptom-level associations when investigating the role of polygenic risk in psychopathology and comorbidity.
For full disclosures and additional details, refer to the original study published in JAMA Psychiatry.
