Pubdate: Sat, 7 August 1999 Source: New Scientist (UK) Copyright: New Scientist, RBI Limited 1999 Contact: http://www.newscientist.com/ Author: Nell Boyce, Washington DC 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. - --- MAP posted-by: Jo-D