The exact causes of ADHD are not known.
Experts know that there are differences in brain chemistry and
brain activity among people with the condition as compared with
those who do not have ADHD. ADHD is not caused by home or school
situations or by poor parenting.
Here is what the experts know:
- Studies of the brain and its functioning show that children and
adults who have ADHD are likely to have abnormal functioning
(dysregulation) of certain neurotransmitters (chemicals in the
brain), as well as in the nerve pathways that regulate
behavior.
- There is a genetic link. ADHD tends to run in families. If one
or both parents have ADHD, their children are more likely to
develop the condition.
- Another factor that may play a role in causing ADHD is the
presence of certain toxins in the environment, such as lead. Such
toxins can interfere with the brain development of children exposed
to them and possibly lead to ADHD.
- Studies show pregnant women who smoke or drink alcohol may have
an increased risk of having a child with ADHD.
Research has shown that there is no evidence that ADHD is caused
by:
- Eating too much sugar
- Allergies
- Immunizations