Causes

Genetics

ADHD is a familial disorder; genetics play a large role and they are the cause of about 92% of cases.

Neurological

Neurological reasons such as:

• Infections during pregnancy, childbirth or the first few months after birth
• Lack of oxygen
• Brain inflammation
• Drinking alcohol during pregnancy
• Smoking during pregnancy

Biological

Neurophysiological and pharmacological studies and EEG tests have shown that the systems of neurotransmitters (dopamine and noradrenaline) in the frontal section of the brain, which play an important role in ADHD, show a chemical imbalance in terms of the reduced amount of chemical conductors. These conductors make it easier for brain cells to complete their tasks and communicate with other parts of the brain.

Environmental

In addition to maternal smoking and drinking mentioned above, there is ongoing research into possible environmental causes.

Additional Resources

• Video: The Genetics of ADHD (Dr Max Muenke)
• Video: The Biological Basis of ADHD (Dr James Swanson)
• Video: Environmental Causes of ADHD (Dr Bruce Lanphear)