The exact cause of ADHD is unknown;
however the following contributing factors may play a role in a child developing ADHD:
* Differences of neurophysiology of the brain anatomy, electrical activity and metabolism
* Drug use during pregnancy such as nicotine and cocaine
* Chronic exposure to low levels of lead influencing behaviour and brain chemistry
* Lack of early attachment where the child does not have enough bonding time with parent or caregiver
* Early traumatic experiences relating to attachment resulting in inattention and hyperactivity.
* Childhood posttraumatic stress disorder due traumatic event which has similar symptoms to that of ADHD but treatment options is different.