The first long-term, large-scale study
designed to determine the safety and
effectiveness of treating preschoolers who
have attention deficit/hyperactivity disorder
(ADHD) with methylphenidate (Ritalin) has
found that overall, low doses of this
medication are effective and safe. However,
the study found that children this age are
more sensitive than older children to the
medication's side effects and therefore
should be closely monitored. The 70-week,
six-site study was funded by the National
Institutes of Health's National Institute of
Mental Health (NIMH) and was described in
several articles in the November 2006 issue
of the Journal of the American Academy of
Child and Adolescent Psychiatry.
"The Preschool ADHD Treatment Study, or PATS,
provides us with the best information to date
about treating very young children diagnosed
with ADHD," said NIMH Director Thomas R.
Insel, MD. "The results show that
preschoolers may benefit from low doses of
medication when it is closely monitored, but
the positive effects are less evident and
side-effects are somewhat greater than
previous reports in older children."
Methylphenidate is the most commonly
prescribed medication to treat children
diagnosed with ADHD. But its use for children
younger than 6 years has not been approved by
the Food and Drug Administration. And until
PATS, very few studies—and no large-scale
ones—have been conducted to collect reliable,
consistent data to help guide practitioners
treating preschoolers with ADHD.
The 303 preschoolers enrolled in the study
ranged in age from 3 to 5 years. The children
and their parents participated in a
pre-trial, 10-week behavioral therapy and
training course. Only those children with the
most extreme ADHD symptoms who did not
improve after the behavioral therapy course
and whose parents agreed to have them treated
with medication were included in the
medication study. In the first part of the
medication study, the children took a range
of doses from a very low amount of 3.75 mg
daily of methylphenidate, administered in
three equal doses, up to 22.5 mg/day. By
comparison, doses for school-aged children
usually range from 15 to 50 mg total daily.
The study then compared the effectiveness of
methylphenidate to placebo. It found that the
children taking methylphenidate had a more
marked reduction of their ADHD symptoms
compared to children taking a placebo, and
that different children responded best to
different doses.