What causes ADHD? New study links potential risk genes to disorder
CTV
A new study has linked potential risk genes to ADHD, potentially furthering research on what causes one of Canada's most common and often misunderstood neurodevelopmental disorders.
While previous research has linked genetic factors to the cause of Attention Deficit Hyperactivity Disorder (ADHD), there is yet to be conclusive evidence to identify the specific genes that can cause the neurodevelopmental disorder.
However, a new study out of Denmark is getting closer to identifying these specific genes and why ADHD can develop in some and not others.
The study, published in the peer-reviewed journal Nature Genetics in January, analyzed data on more than six million genetic variants in 38,691 people with ADHD and 186,843 people without the disorder. The researchers were able to identify 27 variations in the human DNA code that were most present in people with ADHD; however, they estimate there could be as many as 7,300 of these genetic variants.
The study also indicated genes linked to ADHD often have a high level of gene expression in brain tissues during the brain development stage as early on as the embryonic stage, which is between the fifth and 10th week of pregnancy.
“This emphasizes that ADHD should be seen as a brain developmental disorder, and that this is most likely influenced by genes that have a major impact on the brain’s early development,” lead study author Ditte Demontis said in a news release.
According to the Centre for ADHD Awareness, Canada, the most common symptom of ADHD is a reduction in attention span and concentration. People with ADHD can experience being hyperactive by talking excessively or being impulsive, while others can be inattentive and some can experience a combination of both. In Canada, ADHD affects an estimated 1.8 million people.
The study found that these risk genes often affect dopaminergic neurons, which play a major role in a person's behaviour, affecting their mood, stress or a variety of feelings. Researchers also combined their results with data from 4,973 people that underwent neuro-cognitive tests and found these genetic variants can be linked to a person's reduced attention span, short-term memory, and reduced reading and mathematical ability.
