New ADHD findings

November 14, 2011

A combination of rare and common genetic variations could play a part in biological pathways linked to Attention Deficit Hyperactivity Disorder (ADHD).

Cardiff University scientists revealed last year that children with the condition, like those with autism, were more likely than unaffected individuals to carry duplicated or omitted small DNA segments known as (CNVs). The findings suggested that rare genetic variations contribute to ADHD risk. Similar findings have been found for autism, schizophrenia and .

Now a wider study by the same team and colleagues in Eire and Scotland has replicated the initial findings that these large, rare CNVs are more common in children with ADHD than amongst the general population. Their findings additionally suggest a more common type of genetic variant called Single-Nucleotide Polymorphisms (SNPs) may also be relevant to ADHD risk. It has been difficult to identify specific common genetic variants for disorders like ADHD and autism. However the new study found that both rare and common types of genetic variations appeared to impact on the same biological pathways The findings suggest that different types of genetic variations impact on similar pathways that are linked to the disorder.

is characterised by extreme restlessness, fidgetiness, concentration problems and impulsiveness leading to social and educational difficulties. Many affected children also have , autistic type symptoms, dyslexia, developmental problems, motor-coordination difficulties and . For the study published last year, the Cardiff team analysed data from 366 children with ADHD. For the new research, they studied twice as many – 727 – and still found the rare CNVs were more common than in children without the condition.

The team also examined more common SNP variants and found there was no significant difference between children with or without ADHD. However, 13 biological pathways which linked to CNV variants also linked to the SNP variants. The identified pathways affect the development of the central nervous system and four were related to cholesterol, an important component of the brain.

Professor Anita Thapar, Professor of Child and Adolescent Psychiatry at Cardiff University’s School of Medicine, who led the study, said: "These results replicate our finding last year that large, rare copy number variants are significantly more common in children with ADHD than those unaffected. However, we also show that other genetic variants need to be examined and SNPs cannot be ruled out of playing a part. We have also identified 13 biological pathways for further investigation ADHD is a complex disorder like all neuropsychiatric problems which means multiple types of genetic and non-genetic risk factors will be involved".

The full paper Investigating the Contribution of Common Genetic Variants to the Risk and Pathogenesis of ADHD has just been published in the American Journal of Psychiatry.

Explore further: Study finds new ADHD genes, links susceptibility with autism and other neuropsychiatric conditions

Related Stories

Mutant gene linked to ADHD

April 18, 2011

( -- In a recent study published in Nature Medicine, Dr. Eunjin Kim from the Korea Advanced Institute of Science and Technology uncovers a genetic fault that triples the chances of a child having ADHD (Attention ...

Recommended for you

Unhealthy diet during pregnancy could be linked to ADHD

August 18, 2016

New research led by scientists from King's College London and the University of Bristol has found that a high-fat, high-sugar diet during pregnancy may be linked to symptoms of ADHD in children who show conduct problems early ...

Epilepsy may triple ADHD risk, Danish study finds

July 13, 2016

(HealthDay)—Children who suffer from epilepsy or fever-related seizures may face a higher risk of also having attention-deficit/hyperactivity disorder (ADHD), new Danish research suggests.

Exercise may help ease adult ADHD symptoms

July 6, 2016

(HealthDay)—A burst of moderate exercise may improve motivation and energy in adults with symptoms of attention deficit hyperactivity disorder (ADHD), a small new study suggests.

Study highlights multiple factors of ADHD medication use

June 8, 2016

Youth who take Ritalin, Adderall or other stimulant medications for ADHD over an extended period of time early in life are no more at risk for substance abuse in later adolescence than teens without ADHD, according to a University ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.