:: What causes ADHD :: Signs and symptoms of ADHD :: Problems associated with ADHD :: Managing ADHD :: Helping your students :: Students like yours Nobody knows for sure what causes ADHD. Scientific research suggests that people with ADHD have an inefficiency of chemicals called neurotransmitters in the brain. Also, the way the brain uses glucose, its main energy source, seems to be different in people with ADHD. Genetic factors may play a role in ADHD, as the disorder tends to run in families. For some people there is evidence that certain foods can cause ADHD-type symptoms.