Gene variants implicated in ADHD identify attention and language deficits in the general population.

Credit: Centre for Healthy Brain Ageing (CHeBA) 2014.

A new study from researchers at Cardiff University and the University of Bristol suggests that there is a spectrum of attention, hyperactivity/impulsiveness and language function in society, with varying degrees of these impairments associated with clusters of genes linked with the risk for ADHD.  The opensource study is published in the journal Biological Psychiatry.

The team asked the question, are deficits in attention limited to those with attention-deficit/hyperactivity disorder (ADHD) or is there a spectrum of attention function in the general population? The group state that the answer to this question has implications for psychiatric diagnoses and perhaps for society, broadly.  Viewing these functions as dimensions or spectrums contrasts with a traditional view of ADHD as a disease category.

The researchers used genetic data from patients with ADHD as well as data from the Avon Longitudinal Study of Parents and Children (ALSPAC). The ALSPAC is based in England and is a large, ongoing study of parents and children followed since birth in the early ’90s.

They created polygenic risk scores, a ‘composite’ score of genetic effects that forms an index of genetic risk,  of ADHD for 8,229 ALSPAC participants.

They found that polygenic risk for ADHD was positively associated with higher levels of traits of hyperactivity/impulsiveness and attention at ages 7 and 10 in the general population. It was also negatively associated with pragmatic language abilities, such as the ability to appropriately use language in social settings.

The research found that a set of genetic risks identified from UK patients with a clinical diagnosis of childhood ADHD also predicted higher levels of developmental difficulties in children from a UK population cohort, the ALSPAC.

The results provide support at a genetic level for the suggestion that ADHD diagnosis represents the extreme of a spectrum of difficulties. The results are also important as they suggest that the same sets of genetic risks contribute to different aspects of child development which are characteristic features of neurodevelopmental disorders such as ADHD and autism spectrum disorder.

It may be the case that at some point polygenic risk scores may, in conjunction with other clinical information, help to identify children who will struggle in school and other demanding contexts due to attention difficulties.  The objective of this type of early identification would be to provide children who are at risk for difficulties with support so that problems at school may be prevented.

Source:  Reed Elsevier Group PLC


Credit:  Centre for Healthy Brain Ageing (CHeBA) 2014.
Credit: Centre for Healthy Brain Ageing (CHeBA) 2014.