THE THIN LINE

Just What Is The Link Between Hyperactivity Drugs And Cocaine Use?

CONTROVERSY has flared up again over the claim that the drugs used to treat
hyperactive children "prime" them to abuse cocaine. The latest studies
suggest that drug treatment actually makes children with attention
deficit-hyperactivity disorder less likely to become cocaine users.

Children with ADHD---mostly boys---constantly fidget and struggle to
concentrate. Their symptoms can be eased by certain stimulant drugs, the
most common being Ritalin. But in 1995, brain scans suggested that the
distribution of Ritalin in the brain was just like that of cocaine. Since
then, researchers have been studying children with ADHD to see if there is a
link between drug treatment and later cocaine abuse.

Worryingly, a study of more than 5000 children with ADHD done by Nadine
Lambert of the University of California at Berkeley suggested that those who
took Ritalin were three times more likely to use cocaine in adulthood (New
Scientist, 18 April 1998, p 18). But the results have still not been
published and other researchers have argued that the group who were treated
with drugs may have been different---for instance, their ADHD may have been
more severe.

Timothy Wilens and his colleagues at the Massachusetts General Hospital in
Boston have now investigated the use of alcohol, tobacco, marijuana,
hallucinogens and cocaine in what they claim is a better defined group of
boys with ADHD. All the boys were at least 15 years old, and those who took
drugs for the disorder had done so for an average of four years.

Boys with ADHD who were treated with Ritalin or similar drugs were
significantly less likely to have used illegal drugs than those who had not.
Drug treatment seemed to reduce the risk of illegal drug abuse by 85 per
cent compared with the untreated group. Only 1 out of 56 boys undergoing
drug treatment had used cocaine, compared with 3 out of 19 boys who had not
received treatment, Wilens reports in the online edition of Pediatrics (vol
104, e20).

"We're not seeing increased substance use in kids who are treated. We're
seeing decreased substance use," says Wilens. The researchers plan to follow
up the subjects in four years to see whether the risk of drug abuse
increases as the teenagers get older.

Lambert questions the significance of such a small study. But in any case,
she doesn't believe the new findings contradict her work. She notes that her
findings of increased susceptibility to cocaine abuse applied to adults
rather than adolescents. "When we studied our kids at the same age, they
didn't have very high stimulant or cocaine rates either."

But a small unpublished study of adults supports Wilens's findings. Jan
Loney of the State University of New York at Stony Brook recently finished a
follow-up study of treated and untreated ADHD sufferers at the ages of 21
and 23. "Contrary to what everyone had been afraid of, it was actually the
non-medicated kids who used drugs," she says.