• Causes of ADHD in children are attributed to various reasons like:
• Emotional trauma (like death in family or divorce)
• Undetected seizures
• Anxiety followed by depression
• Existing medical disorders concerning brain
• Smoking and drug abuse in pregnancy
• Environmental toxins (like lead and polychlorinated biphenyls)
• Heredity (1 in 4 children diagnosed have at least one relative with the same condition)
• Most of the causes originate from the biological aspects.
• It is believed that the change in the structure of the brain might be one of the dominant reasons.
• Further, there are certain environmental agents that could possibly modify a child's behavior.

Given below are some of the factors that have been identified by the researchers:

1. Modified Anatomy and Brain Routine

Children affected by this disorder have notable differences in the function of the brain as compared to their counterparts. The chemicals present in the brain, namely neurotransmitters, are responsible for this behavior. These neurotransmitters are essential for the interaction of the cells present in the brain. In affected children, a neurotransmitter called dopamine tends to malfunction, thereby causing unfavorable consequences, that include impulsiveness, lack of concentration, and hyperactivity. Further, it has been scientifically proved that a child with this disorder has significantly smaller volume of brain, as compared to a normal child. The affected children seem to be less sensitive in situations, where they are either complimented or punished.

2. Genes

This disorder is also believed to be transferred from parents, who are diagnosed of hypertension. Every fourth child affected by this disorder, has a relative affected by the same. This disorder is also more commonly found in identical twins. If the parents tend to have psychiatric disturbance, then there are possibilities of a child acquiring this disorder.

3. Maternal Factors

Pregnant mothers habituated to smoking are at higher risk of having an affected child. Likewise, using alcohol or other drugs during the gestation period can retard the activity of neurons that produce dopamine. Exposure to chemical poisons such as polychlorinated biphenyls (PCBs) during pregnancy may also be considered as one of the risk factors. This chemical is widely used in the pesticide industry. Consumption of drugs like cocaine has proved to hinder the normal growth of the brain receptors. Also, there are cases where the mothers are less affectionate and are very critical towards their own children. They also tend to severely punish the child for literally a tiny reason.

4. Exposure of a Child to Environmental Poisons

Exposure to environmental toxins such as lead and PCBs is another risk factor. Prolonged exposure to lead levels might even result in violent behavior. Lead is even found in sand, dust, and also in water pipes. Other possible environmental factors include pollution, consumption of food stuffs that have artificial colors, and exposure to fluorescent light. -Interestingly, even sugar has proved to shoot up the hyperactive behavior in certain cases.

5. Other Factors

Watching television for a longer period could possibly make the brain want a constant stimulation. Deficiencies in the child's daily diet accounts for poor nutrition and could result in the modified behavior. Children who are devoid of love and security might realize that their needs are not met, and this might lead to the development of symptoms similar to those of ADHD