NEW YORK – Managing adherence, selecting the proper agent, and keeping a keen watch out for the risk of substance abuse are key to successfully treating attention-deficit/hyperactivity disorder in older adolescents and adults, according to Dr. Timothy E. Wilens.
“One thing we don't talk enough about is adherence,” Dr. Wilens, associate professor of psychiatry at Harvard Medical School, Boston, said at a pharmacology update sponsored by the American Academy of Child and Adolescent Psychiatrists. “You can do everything right, and still, when you look at adherence, it's terrible.”
He cited a study presented in 2005 at the annual international conference of Children and Adults with Attention Deficit/Hyperactivity Disorder showing that among 5,600 patients prescribed medications for ADHD, 50% stopped taking the drugs within 3 months, and 80% discontinued by 18 months.
Perhaps the gravest risk in treating older adolescents and adults for ADHD, and one which Dr. Wilens has studied extensively, is the abuse of substances–whether cigarettes, marijuana, or the very medications being prescribed for the ADHD. “Substance abuse is a major consideration,” he said, citing a study he presented last year at a meeting of the American Academy of Addiction Psychiatry showing that 20% or so of ADHD patients are dependent on an addictive substance at the age of 25. That comes to more than twice the rate of controls.
Because most ADHD patients are treated well before adulthood, he said, talking with patients early about substance abuse as a risk factor is important. “ADHD doubles their risk of having substance abuse 10 years later,” said Dr. Wilens, who also serves as director of substance abuse services, clinical and research programs in pediatric psychopharmacology at Massachusetts General Hospital. “Fifty percent of the kids who have ADHD and are smoking will go on to substance abuse. I say to them when they're young, 'I'm really concerned that you have twice the risk of becoming an addict with marijuana if you begin using it.' I tell them this over and over, 'You cannot do like your friends.'”
A reassuring result was seen in a case-controlled, prospective study led by Dr. Wilens involving 114 female adolescents diagnosed with ADHD. Five years after initial treatment, those who had received stimulant medications were significantly less likely to be smoking, drinking alcohol, or abusing drugs than were those who had not undergone treatment with stimulants (Arch. Pediatr. Adolesc. Med. 2008;162:916-21). “Treatment reduced cigarette smoking and substance abuse,” Dr. Wilens said. “That is great news.”
Other studies tracking such patients into adulthood, he noted, have likewise found that stimulant treatment for ADHD does not raise the subsequent risk of substance abuse, although most have found that it does not lower the risk, either.
For patients already diagnosed as substance abusers, Dr. Wilens said, there have been four double-blind studies showing that treating them with stimulants for ADHD results in no significant improvement of either condition.
“From the safety side, there was no worsening of substance use,” he said. “But it's not doing much. So if you have an active abuser who comes to you and says, 'You need to treat my ADHD so I'll get better,' don't fall for that.”
For patients who admit to using marijuana, he recommended asking about weekly frequency. “I would not refuse to treat their ADHD because they're smoking marijuana on weekends,” Dr. Wilens said. “But if they're smoking seven to eight joints a week, there's no evidence that treating for ADHD will benefit it. And telling them you won't treat until they stop gives them a message.”
If a physician suspects that a new patient is seeking ADHD medication merely to abuse or sell it, Dr. Wilens said: “Have them come back for a second session before you give them a prescription. Slow down the evaluation process. Ask them to bring in something from their parents or elsewhere to confirm the diagnosis. If they're trying to scam you, if they think you're onto them, they often won't come back for a second visit.”
When prescribing a stimulant to ADHD patients in whom the potential for abuse is suspected, he added, “I like to use extended release. Don't hand somebody you're worried about an immediate-release methylphenidate. If you do, you might as well hand them a mortar and pestle.” Indeed, while 11% of patients he's been tracking in an ongoing study have sold the stimulant medications they were prescribed for ADHD, all those cases involved immediate-release formulations rather than sustained release.
Beyond the risks of substance abuse, Dr. Wilens addressed other issues unique to older adolescents and adults with ADHD. He cited his own recent paper in the Journal of Clinical Psychiatry (2009;70:1557-62) showing that the most common presenting symptom in adult ADHD, present in more than 90% of cases, is being easily distracted.