What is Attention Deficit Hyperactivity Disorder (ADHD)? 

ADHD is generally considered to be a neurobiological disorder. It is characterised by impulsivity, hyperactivity and the inability to sustain focused attention. Researchers believe that the symptoms of ADHD are caused by an imbalance of two chemical messengers in the brain.

There are three types of ADHD, based on the the DSM-IV, the latest diagnostic criteria of the American Psychiatric Association:

1. ADHD with the combined characteristics of hyperactivity, impulsivity, and inattention;
2. ADHD with inattention as the primary characteristic; and
3. ADHD with hyperactivity and impulsivity as primary characteristics.

The first and third types are most often and easily identified, as children with these two types of ADHD tend to have symptoms that are highly noticeable. They are usually loud, extremely active, risk-takers, rebellious towards authority, and prone to engaging in dangerous behaviour. The second type of ADHD is more prevalent in females. Children who fall into this group often lose their personal belongings, have difficulty working alone or finishing tasks, and are lost in their own thoughts.

Some children are inattentive and impulsive but not hyperactive. They are termed as having Attention Deficit Disorder (ADD). Children with ADD are like those with ADHD, except that they do not exhibit much of the hyperactivity symptoms.

Researchers estimate that ADHD occurs in as many as 3 – 5% of school-going children. That translates into two ADHD children in a class of 40 in the Singapore context. ADHD/ADD is usually diagnosed when the child is aged 6 - 10, although some children may be diagnosed earlier or later. Boys are 4 - 6 times more likely than girls to have ADHD/ADD. Hence in this website, the male gender will be used when referring to the ADHD/ADD child.