ADHD is one of the most common childhood disorders and
can continue through adolescence and into adulthood. The
average age of onset is 7 years old.
The American Psychiatric Association (APA) states in
the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) that 5% of children have ADHD. However, studies
in the US have estimated higher rates in community samples.
As of 2011, approximately 11% of children 4-17 years
of age have been diagnosed with ADHD. Boys were affected
more likely than girls.
Prevalence of ADHD diagnosis varied substantially by
state: 5.6% in Nevada (lowest) and 18.7% in Kentucky (highest).
On average, there are 1-3 children who have ADHD in
every classroom of 30 students, and the rate of their emotional
development with ADHD is 30% slower than their non-ADHD
peers. These children were also more likely to have major
injuries, hospital inpatient, hospital outpatient or emergency
65% of children with ADHD have problems with defiance,
non-compliance and other problems with authority figures.
Accordingly, 25% of students with ADHD have other serious
learning problems in one or more areas such as oral expression,
listening skills, reading comprehension and math.
21% of teens with ADHD skip school repeatedly, 35% eventually
drop out of school, 45% have been suspended and 30% have
failed or had to repeat a year of school.
Studies show that the number of children being diagnosed
with ADHD is increasing, but it is unclear why.