Causes of ADHD (Attention Deficit Hyperactivity Disorder). ADHD has multiple causes. Causes are both from the environment. And genetics. There are many researchers that research on the causes of ADHD but have not been able to know the exact cause. The group of guys we have interest in causing ADHD. Three reasons. The first is gene. Gene organisms inheritance. If a relative is ADHD. Many ADHD children are likely to be four times more than normal. The second cause is. The imbalance of chemicals in the brain. The reason for this is caused by a chemical in the brain's Web mail function of controlling the body and the concentration of child disorders. Children born to control behavior does not make a diagnosis ADHD. Causes. Three Drinking alcohol and smoking. The reason for this is due to the mother having inappropriate behavior during pregnancy. The drinking of alcohol cholesterol and smoking are toxins that affect the development. The brain of a child is in the womb. Finally, whether the reason mentioned above. Even when I was pregnant, should take care of themselves and their children in the womb, to reduce the risk that children will be as ADHD