A recent theory of ADHD predicts a deficiency in
sense of time in the disorder. Two studies were conducted
to test this prediction, and to evaluate the effects of
interval duration, distraction, and stimulant medication
on the reproductions of temporal durations in children
with ADHD. Study I: 12 ADHD children and 26 controls (ages
6–14 years) were tested using a time reproduction
task in which subjects had to reproduce intervals of 12,
24, 36, 48, and 60 s. Four trials at each duration were
presented with a distraction occurring on half of these
trials. Control subjects were significantly more accurate
than ADHD children at most durations and were unaffected
by the distraction. ADHD children, in contrast, were significantly
less accurate when distracted. Both groups became less
accurate with increasing durations to be reproduced. Study
II: Tested three doses of methylphenidate (MPH) and placebo
on the time reproductions of the 12 ADHD children. ADHD
children became less accurate with increasing durations
and distraction was found to reduce accuracy at 36 s or
less. No effects of MPH were evident. The results of these
preliminary studies seem to support the prediction that
sense of time is impaired in children with ADHD. The capacity
to accurately reproduce time intervals in ADHD children
does not seem to improve with administration of stimulant
medication. (JINS, 1997, 3, 359–369.)