There are 12 genetic risk factors for ADHD, a new study found.
For the first time, researchers at the University of Cardiff have found that there are common genetic tendencies related to a disorder that is found in about one in 20 children.
Genetic information from about 55,000 people was analyzed to identify the differences between people with and without this condition.
The team also believes that these same genetic factors are shared with other psychiatric and physical disorders, including depression, obesity and type 2 diabetes.
Dr Joanna Martin, a research associate at the University of Cardiff, said: "We identified 12 genomic regions where people with ADHD differed compared to disadvantaged individuals, and several of these regions are in or near the genes with a known relationship to biological processes that are involved in healthy brain development. "
By researching more than 20,000 people with ADHD and 35,000 without studies, this study was the highest in the state to date, and researchers believe it could help in better treatment in the future.
Professor Anita Thapar said: "This study marks a very important step in starting to understand the genetic and biological background of ADHD.
"Genetic risk variants that relate to this condition play a significant role in the brain and other basic biological processes.
"The next step is to determine the exact role of these genes in ADHD to help us inform better treatments to support those affected by these conditions."
She added: "This is a feature of the study because it involved patients from all over the world.
"This large number of patient samples is missing from ADHD, which means that our understanding of ADHD genetics is lagging behind physical disorders and other psychiatric disorders such as schizophrenia and depression.
"Every person with the ADHD who participated in the research makes a real difference to improve our understanding of the situation and we hope that this study will lead to a higher level of participation and greater interest in Britain in support of ADHD research."
– Press Association