According to a new study published in the online version of the medical journal The Lancet on Sept. 30, the majority of children who have attention deficit hyperactivity disorder (ADHD) carry a genetic abnormality that may predispose them to the condition.
Researchers at the Cardiff University School of Medicine in Wales analyzed genetic data of 366 children with ADHD and 1,047 children without it. They found that the children with ADHD have significantly more copy number variants in their DNA. According to the study, copy number variants (CNVs) are large, rare chromosomal deletions and duplications.
While having a high number of CNVs has already been known to be associated with a higher rate of other neurological disorders such as autism and schizophrenia, this is the first study to link this genetic abnormality to ADHD. The researchers suggested ADHD and autism may share a biological basis because they have overlapping symptoms (particularly learning problems) and they share the same genetic abnormality.
ADHD is a common condition affecting three to five percent of children in the United States, according to U.S. National Institute of Mental Health. Some medical professionals have blamed the increasing prevalence of this condition on social conditions such as high-sugar diets or bad parenting. These new findings, however, offer tentative proof that ADHD could be a disorder with a biological basis and "suggest that ADHD is not a purely social construct."
The researchers do note, however, that presence of CNVs does not mean that a child will necessarily develop ADHD or another neurological disorder; it only indicates an increased likelihood of developing such a condition. Future clinical use of these findings is still unclear; more research is needed to fully understand the links between this genetic abnormality and the neurological upshot.
To find out more about this disorder, visit the ADHD Learning Center.