U.S STUDY SHEDS SOME LIGHT ON THE EFFECTS OF RITALIN

Hyperactive Kids Don't Experience A 'high,' Researchers Say

WASHINGTON (Reuters) - Researchers say the drug Ritalin, which is given to
many hyperactive youngsters, does not become addictive when taken orally.

That's because it takes an hour for the stimulant, known generically as
methylphenidate, to reach its peak concentration in the brain.

The uptake is much slower than that of an addictive drug such as cocaine,
which reaches the brain in as little as five minutes.

"The fact that Ritalin taken orally is drawn so slowly into the brain is a
likely reason why patients do not experience a 'high' from this means of
use," say researchers at the National Institute on Drug Abuse, which funded
the study.

The use of Ritalin to treat attention deficit disorder and attention
deficit hyperactivity disorder is controversial, with some critics arguing
that it's wrong to drug children.

But several studies have supported the use of the drug.

The American Medical Association says it has found little evidence that
Ritalin, made by Novartis and also available generically, is over-used.

The association estimates that 3 to 6 per cent of the school-age population
may have attention disorders.

Children diagnosed with the conditions exhibit a series of problems
including inattentiveness, poor listening skills, failure to follow
instructions and difficulty organizing tasks.

Market research firm IMS Health says 13.9 million prescriptions of
stimulants including Ritalin were dispensed to U.S. children during the
last school year, an 81.2 per cent increase from the 7.7 million recorded
five years earlier.

Dr. Nora Volkow and colleagues at Brookhaven National Laboratory in New
York used brain scans to measure the drug's effects in the brain.

Positron emission tomography scans on seven adult volunteers who do not
have attention disorders showed the drug did what it is supposed to do -
block chemicals known as dopamine transporters, which in turn cuts down on
the amount of dopamine used in the brain.

Dopamine is a neurotransmitter, or message-carrying chemical, linked with
feelings of euphoria.

It is believed to be at the heart of drug addiction.

Of the seven volunteers, only one reported Ritalin produced a "high." In
contrast, Ritalin given intravenously does produce a "high" and can be
addictive.