There's no mistaking kids with Attention Deficit Hyperactivity
Disorder (ADHD)--they are easily distracted, impulsive, and
hyperactive. So, it's hardly a stretch to suspect problems with
a chemical messenger in the brain, norepinephrine, that helps
control attention. Yet scientists have failed to nail down a
link. Now, a new study has for the first time connected the dots
by identifying a mutation that indirectly boosts norepinephrine
levels. The findings, if replicated, could improve understanding
of the disorder and better drugs. Norepinephrine is one of the
most important chemical messengers neurons use. The cells have
tiny pumps called transporters that maintain a balanced level of
the messenger in the brain. Both the messenger and the
transporter play significant roles in disorders such as anxiety
and depression. But the only solid evidence to for a role with
ADHD has come from the drug Strattera, which targets the
transporter and is used to treat some ADHD cases. Other studies
have failed to conclusivel