attention deficit hyperactivity disorder (ADHD)

attention deficit hyperactivity disorder (ADHD) - A behavioural disorder in which a child has a consistently high level of activity and/or difficulty in attending to tasks. Attention deficit hyperactivity, or hyperkinetic, disorder affects up to 1 in 20 children in the UK.

The disorder, which is more common in boys, should not be confused with the normal boisterous conduct of a healthy child. Children with ADHD consistently show abnormal patterns of behaviour over a period of time. An affected child is likely to be restless, unable to sit still for more than a few moments, inattentive, and impulsive.

The causes of ADHD are not fully understood, but the disorder often runs in families, which suggests that genetic factors may be involved. ADHD is not, as popularly believed, a result of poor parenting or abuse.

Symptoms develop in early childhood, usually between the ages of 3 and 7, and may include inability to finish tasks; short attention span; inability to concentrate in class; difficulty in following instructions; a tendency to talk excessively, frequently interrupting other people; difficulty in waiting or taking turns; inability to play quietly alone; and physical impulsiveness.

Children with ADHD may have difficulty in forming friendships. Self-esteem is often low because an affected child is frequently scolded and criticized. Treatment includes behaviour modification techniques, both at home and at school. In some children, avoidance of certain foods or food additives seems to reduce symptoms.

In severe cases, stimulant drugs, usually methylphenidate, may be prescribed. Paradoxically, the use of stimulants in ADHD reduces hyperactivity and improves concentration. In general, the condition improves by adolescence but may be followed by antisocial behaviour and drug abuse or substance abuse.