

Genetic studies, including family, twin and adoption studies, show ADHD is a highly heritable disorder. No single ADHD gene appears responsible for causing ADHD. Instead, research suggests it is likely to result from number of interacting genes. Expression of these genes is thought to result in alterations in brain structure, neurochemical composition and availability, and brain connectivity and function.
It is estimated that ADHD effects around 5% of the Australian population, that is about one in 20 people or about 1 million Australians.
