It occur before or after a baby is born and possibly occur in children between the ages of 3–5 years old.

ATTENTION-DEFICIT HYPERACTIVITY DISORDER (ADHD)

The occurrence of abnormal activities in certain parts of the brain causing the nerve cells to produce unusual signals. A person suffering from epilepsy may be

hyperactive, unable to concentrate and gets easily bored.

Sedative drugs (depressants)

Narcotic drugs

PARKINSON’S DISEASE

Autism

Hallucinogenic drugs

This disease is caused by the deterioration and death of motor neurones that control the movement of muscles such as chewing, walking and talking.

the myelin sheath in the brain and spinal cord.

ALZHEIMER’S DISEASE

Increases the activity of the central nervous system • Excessive use causes temporary euphoria which is followed by depression