The Ritalin Riddle
The rumors haunted Kay Gilmore like they do most parents whose children are diagnosed with attention deficit hyperactivity disorder. If she gave her child medications like Ritalin, a tightly regulated stimulant, would she be increasing the risk that he would later abuse drugs?
That was the fear, the innuendo, that for years has swirled around parents dealing with the common childhood behavioral disorder.
“It crosses every parent’s mind,” says Gilmore, of Newbury Park. “The logical assumption is if you are giving your child stimulants, there might be a relationship to drug abuse.”
However, for many families, including the Gilmores, Ritalin and other stimulant medications have helped their children to perform well in school, behave appropriately in social situations and cooperate better at home.
And, over the past decade, other outstanding concerns--that the medication might stunt growth or cause the child to become addicted to stimulants--have been largely allayed.
Now, the lingering question of substance abuse may also be nearing a resolution. In a study released last week in the journal Pediatrics, researchers at Massachusetts General Hospital in Boston found that children with attention deficit hyperactivity disorder, or ADHD, who receive stimulant medication were far less likely to abuse drugs during adolescence compared to children with the disorder who were not medicated.
“I think this will be an important message to parents” and researchers, says psychologist Stephen Hinshaw, director of the clinical psychology training program at UC Berkeley and an expert in treatment of ADHD. The new study is the latest in a long history of research on stimulants that has produced mixed messages on whether stimulants can increase drug abuse. While some studies have found no connection, others have come to alarming conclusions.
For example, as recently as November, a UC Berkeley education professor presented the results of a 26-year study that tracked children well into adulthood and found a marked increase in drug abuse among children treated with stimulants.
And several earlier studies overwhelmingly concluded that children with the disorder (no matter what kind of treatment they receive) are more likely to abuse drugs--including tobacco, alcohol, marijuana, cocaine and stimulants--than children without ADHD.
The new study, undertaken to try to clarify the controversy, is considered the most scientifically rigorous to date. And although it is not the final word on the matter, the findings are convincing, several experts say.
The study--which followed 212 boys for four years--suggests that stimulant medication protects children with ADHD from a further risk of substance abuse, perhaps by helping them function better at school and home.
“If the medication has a good effect, which it does in 80% of children, then it reduces a lot of stress and anxiety. And that would be the mechanism to reduce substance abuse. But it doesn’t do it in all cases,” says Dr. James Swanson, a UC Irvine professor of pediatrics and a leading researcher on ADHD.
In contrast, children who do not receive help in coping with the problems related to ADHD may wind up as social outcasts or school dropouts, which in turn can lead to substance abuse, says Matthew Cohen, president of the Children with Attention Deficit Disorders, a national support group based in Landover, Md.
“Substance abuse can be an outgrowth of the difficulties a child is having,” Cohen says. “This study helps to dispel some of the erroneous information that is out in the media and on the street about the impact of using medication.”
Resolving the question of stimulants’ link to substance abuse can hardly be overstated, according to experts, because of the number of children who receive, or potentially could receive, medication. An estimated 3% to 5% of school-age children are thought to have ADHD, making it the most commonly diagnosed behavioral disorder of childhood, according to a 1998 statement by the National Institutes of Health.
Symptoms of the Disorder
Children with the disorder typically have a lot of trouble paying attention, concentrating on tasks, and are easily distracted and often impulsive. There are two major subsets of the disorder: one in which children have an attention disorder but are not unusually active, and one in which children are also extremely active, fidgety and restless.
If not treated with either counseling therapies or medication, children with the disorder often struggle in school and wreak havoc at home.
Throughout the 1990s, diagnosis of ADHD has accelerated rapidly, with enormous numbers of children increasingly being treated with stimulant medications, including Ritalin, Dexedrine, Adderall and Cylert. Last year, for example, more than 2.2 million prescriptions were written for Ritalin. Stimulants work by affecting areas of the brain that support attention and organization.
Long thought to be exclusively a childhood illness that required only temporary treatment with medication, newer research has shown that 50% of children with ADHD may carry the disorder into adulthood.
“There has been a dramatic increase in use of stimulants over the last five years,” Swanson says. “Children are staying on medication longer than they used to. It used to be they stopped at puberty, but more are staying on in the teen years.”
So the idea that stimulant medication is linked to drug abuse has become hugely important. Even the National Institute of Drug Abuse has indirectly addressed the potential for a substance abuse catastrophe by helping to fund much of the recent research.
Stimulants, which are amphetamines, are a commonly abused and addictive class of drug in American culture. In addition, animal studies have suggested a physiological mechanism that would pave the way for abuse.
“Studies in rats and mice have shown that when given stimulants early in development they go on to want to self-administer stimulants if given the chance,” Hinshaw says.
But, he points out, the large amounts of stimulants fed to laboratory animals in studies were much higher and do not mimic the controlled, low-dosing used for ADHD treatment in children.
However, Nadine Lambert, a UC Berkeley education professor who is an expert in learning disorders, suggests that animal studies show that users of stimulants can become sensitized to the drug.
And, in her study on ADHD, presented in November at a National Institutes of Health meeting, Lambert followed 492 children for 30 years, from elementary school into adulthood. She found that both treatment with stimulants and the severity of the disorder were linked to much higher rates of smoking once the children stopped taking the medication and to later abuse of cocaine and other stimulants.
“There is some interaction between stimulant use and initiation into tobacco use. And tobacco is a gateway drug,” she says. “My thinking now is that [people with] ADHD smoke because it operates in the same way the stimulants do. Tobacco is a stimulant. It helps them concentrate and function the same way.”
Study Results Called Skewed
Lambert’s study, however, has not been widely embraced among ADHD researchers. Critics say her results could be skewed because three decades ago only children with severe behavior disorders were put on medication.
“Dr. Lambert is probably picking up the most severe kids, including those who have conduct disorder,” says Dr. James McGough, an associate clinical professor in UCLA’s division of child and adolescent psychiatry. In a study of adults with ADHD, McGough found that the presence of conduct disorder made nicotine use 20 times more powerful.
Conduct disorder is a behavioral disorder distinct from ADHD in which a child severely acts out with aggression and disregard for rules and which is strongly linked to subsequent substance abuse.
But, Lambert says: “People need to know if there is a risk. I don’t think [stimulants] are a harmless substance.”
The most recent study, by Dr. Timothy Wilens and his colleagues at Massachusetts General Hospital, reflects more modern methods to diagnose and treat ADHD, experts say. Wilens’ study is also the first published, long-term, controlled trial looking at stimulant treatment and later substance abuse.
The study followed three groups of boys for four years, concluding when the boys were all age 15 or older. Fifty-six of the boys had ADHD and were treated with stimulants; 19 had ADHD but were not medicated; and 137 were boys without ADHD but who were similar in age, race and economic status.
As expected, children without ADHD had the lowest rates of drug abuse. But among children with ADHD, those treated with stimulants experienced an 85% reduction in risk.
“This shows us that stimulant treatment brings the risk down significantly, but not all the way back to the non-ADHD group. We don’t know why that is,” says Wilens.
Reducing Later Drug Risks
According to Wilens, the study mimics other preliminary research from the National Institute of Drug Abuse, which suggests that early and aggressive treatment of children with other types of psychiatric and behavior disorders may reduce the later risk of substance abuse.
“The issue becomes: Is substance abuse preventable?” Wilens says. “Maybe if you treat the underlying psychiatric condition, you can reduce the risk of substance abuse.”
Nevertheless, many questions remain. For example, Wilens’ study only followed kids through their midteens. While severe substance abuse problems often begin in the early teen years, the major risk period for developing abuse disorders is around age 18 to 19.
The study will continue to follow the boys until adulthood, Wilens says.
More research is also needed to look at the impact of medication on girls and members of various ethnic groups with ADHD.
“We have almost no long-term follow-up in those groups,” Hinshaw says.
Moreover, the often-repeated fear that too many children are being improperly diagnosed with ADHD and treated with stimulants must be closely addressed, he says. Wilens’ study showed medication had a good effect among children who were properly diagnosed.
“Are we treating too many kids with stimulants?” Hinshaw says. “Are some kids underachievers or lack perfection instead of having ADHD? What we really need now is careful assessment. You don’t diagnose ADHD in a 10-minute office visit.”
