This article is more than 5 years old. Information may no longer be current.

Genetic risk scores may indicate risk for persistent ADHD symptoms

Persistence of ADHD symptoms across childhood and adolescence was associated with polygenic risk scores for ADHD, according to recent findings.

“Although ADHD is relevant across the lifespan, most children show a decline in symptom levels across childhood and adolescence, which also occurs in other childhood-onset neurodevelopmental disorders, such as autism spectrum disorder, communication disorders, and specific learning disorders. The determinants of the persistence of a neurodevelopmental disorder are not fully understood, although for ADHD, severity of initial symptoms, comorbidities, cortical maturation, and family history of ADHD, among other factors, have been considered as contributors,” Lucy Riglin, PhD, of Cardiff University, United Kingdom, and colleagues wrote.

To determine if genetic risk variant load for ADHD, as indicated by polygenic risk scores, is associated with population-based ADHD symptom trajectories in childhood and adolescence, researchers assessed data from the Avon Longitudinal Study of Parents and Children for 9,757 children with data on ADHD symptoms at multiple time points since September 1990. Polygenic risk scores (PRS) were generated using results from a genome-wide association study.

Researchers identified four ADHD symptom trajectories among the cohort: low (82.6%), intermediate (7.7%), childhood-limited (5.8%) and persistent (3.9%).

Mean PRS for ADHD were higher among children in the persistent trajectory, compared with each of the other three trajectories (P = .03).

Findings were specific to PRS for ADHD and PRS for other psychiatric disorders did not differ across trajectories, according to researchers.

Multi-morbidity was highest among children in the persistent trajectory (P < .001) and was associated with persistence of ADHD symptoms independent of PRS.

“We found genetic risk of ADHD to be associated with the developmental course of ADHD traits from early childhood to adolescence in the general population: specifically, ADHD genetic loading was highest in children with persistent symptoms,” the researchers wrote. “Genome-wide association studies may benefit from deeper phenotyping of cases to characterize the developmental course of psychiatric disorders. Persistence of ADHD was also associated with greater multi-morbidity of childhood neurodevelopmental impairments and conduct problems, which may be a phenotypic correlate of genetic loading and help to identify children with ADHD who are most likely to show persistence of symptoms into adolescence.” – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.