Prevalence

• Affects about 7% of US population• Children with ADHD have been identified in most

countries• ADHD is 3 to 5 times more common in boys than girls• Usually children with ADHD continue to exhibit the

disorder through adolescence and into adult years• Adult prevalence is between 2-4%• Almost half the referrals to mental health practitioners in

schools, clinics, or private practices are to treat children who have problems related to inattention, hyperactivity, or impulsivity

Causes

• Environmental agents – there is a possible correlation between the use of cigarettes and

alcohol during pregnancy and risk for ADHD in the baby.

– High levels of lead in the bodies of young preschool children may also be associated with ADHD. This is not as prevalent as it once was since lead is no longer allowed in paint or pencils.

• Brain injury – One early theory was that some children who have suffered

accidents leading to brain injury may show some signs of ADHD, but only a small percentage of children with ADHD have been found to have suffered a traumatic brain injury.

Causes (cont’d)

• Food additives and sugar – Symptoms of ADHD are exacerbated by sugar or food additives

– In 1982, it was found that diet restrictions helped about 5% of children with ADHD, mostly young children who had food allergies.

– A more recent study found that using sugar one day and a substitute on alternate days, without parents, staff, or children knowing which substance was being used, showed no significant effects of the sugar on behavior or learning.

• Genetics– Attention disorders often run in families

– Studies indicate that 25% of the close relatives in the families of ADHD children also have ADHD, whereas the rate is about 5% in the general population.