By Connie Prater and Shari Rudavsky

People who use cocaine regularly may have a harder time breaking the habit if they used Ritalin or the club drug Ecstasy in their youth, a University of Miami study suggests.

The number of U.S. children and adolescents who were prescribed Ritalin and other stimulants surged dramatically in the 1990s.

The study, conducted on laboratory mice, found that rodents given Ritalin and Ecstasy, then later cocaine, showed higher sensitivity to cocaine than those that hadn’t been exposed to the first two stimulants.

”If they start using drugs, these guys that have been preexposed to Ritalin and Ecstasy may be more susceptible for relapse than others,” said Yossef Itzhak, a UM professor of psychiatry and the lead researcher on the study.

But Itzhak noted the study did not mirror real life because the mice did not have Attention Deficit Hyperactivity Disorder, the condition for which Ritalin is normally prescribed. One other caveat: It’s not clear how the relatively high doses of Ritalin he looked at for mice would translate into humans.

`WARNING SIGNAL’

”Higher doses may be much more dangerous than therapeutic doses,” he said, adding that his study may be more relevant for those who abuse Ritalin than those who take it on a carefully monitored prescription basis. “For Ritalin, caution should be used. For Ecstasy-using adolescents it’s a warning signal.”

Itzhak and his associates will present the results on Wednesday in Bal Harbour during the 65th annual meeting of the College on Problems of Drug Dependence, a national group of more than 1,000 scientists.

Ritalin is a stimulant used to treat millions of children and adults diagnosed with ADHD, thought to occur when the brain fails to produce a sufficient amount of a neurochemical called dopamine. Ritalin provides the chemical stimulant the brain lacks.

In the 1990s, the number of U.S. prescriptions for Ritalin and similar drugs rose fivefold to nearly 20 million by 2000, according to IMS Health, a national prescription auditing firm. About 80 percent of the prescriptions are written for children diagnosed with ADHD.

COLLEGE STUDENTS

Moreover, this doesn’t include an increasing number of college students abusing Ritalin for a high. The Partnership for Drug-Free America estimates that 9 percent, or 2.1 million teens, have taken Ritalin or similar drugs without a prescription.

”They trade it and they sell it,” said Itzhak. “It has so many characteristics of other types of stimulants.”

Ecstasy, or MDMA, is a methylated amphetamine that causes hallucinations. The Florida Department of Law Enforcement reported MDMA contributed to the deaths of 24 people statewide in 2002 and 37 the previous year.

According to the Partnership, about 1.1 million use Ecstasy on a regular basis.

Dr. Alan Singer, a South Miami psychiatrist who has treated adults and children with ADHD, said the UM study differs from earlier studies showing how children treated with Ritalin for ADHD have higher self-esteem in adulthood, and are less likely to abuse drugs than those diagnosed with ADHD and aren’t treated.

Still, he acknowledged, “The idea that stimulants predispose you to later substance abuse is something that clinicians have worried about for a very long time.”

CHANGES IN BRAIN

While Itzhak said that the exact mechanism behind his findings remain unclear, the use of these drugs does appear to produce long-term changes in the brain. Previous drug exposure sensitizes the regions of the brain associated with reward, he said.

”This is the million-dollar question, how to avoid or prevent changes in the brain so that they would not produce this factor for relapse and drug-seeking behavior,” said Itzhak.

The study had three groups of 4-week-old mice — those given Ritalin, those given the same dosage of Ecstasy and those given saline solution. They received one dose a day for seven days.

”We left them drug-free for one month with no treatment,” Itzhak said.

The researchers then gave all three groups cocaine daily for seven days. There was no significant difference among the three groups in their sensitivity to the drugs. They waited another two weeks and gave each group a smaller dose of cocaine.

The Ecstasy and Ritalin groups showed very high sensitivity to the cocaine, Itzhak said, while the mice that had gotten saline solution showed little impact.

Although Itzhak looked only at cocaine, he said it was possible that his results might apply to other psycho-stimulants, such as amphetamines.
 

Author: Connie Prater and Shari Rudavsky
Source: Northwest Center for Health & Safety