Except in the law, there is no formal boundary between youth and adulthood.
That's a good point to remember when young people treated for
attention-deficit/hyperactivity disorder (ADHD) become old enough to vote and
migrate from pediatricians to adult internists for their medical care, said
Paula Riggs, M.D., an associate professor of psychiatry at the University of
Colorado School of Medicine.
"There's nothing magical about turning 18," said Riggs, in an
interview with Psychiatric News. "Some young people with ADHD
have symptoms that continue into adulthood, so there's no cut
If medications have worked to control symptoms, there is no indication that
a change is necessary, she said.
Nevertheless, some unanswered questions about this transition call for more
research into its consequences, according to Heather Ashton, Peter Gallagher,
and Brian Moore of the Department of Psychiatry at the University of
Newcastle-upon-Tyne, in the United Kingdom, in an article in the september
Journal of Psychopharmacology.
They explored the literature on the long-term risks of psychostimulants,
their effects on the developing brain, and whether those drugs should be
continued or withdrawn as patients age into adulthood.
On one hand, they said, "the psychostimulants used therapeutically in
adhd share major pharmacological properties with cocaine and amphetamine....
[and] there is a high rate of comorbidity (approximately 30 percent to 70
percent) of substance-abuse disorders and ADHD in human adolescents and
On the other hand, they noted that patients treated with psychostimulants
for ADHD present half the risk of misusing drugs compared with untreated
subjects. There is evidence of a protective effect against later substance
abuse when ADHD is diagnosed and treated in childhood.
"Psychostimulants don't lead to drug abuse," Riggs maintained.
Comorbid ADHD and substance abuse should be treated together, she said, citing
studies that found psychostimulants helped with ADHD symptoms and didn't
worsen drug abuse. Reducing the latter requires treatment designed
specifically for substance abuse. She is now completing work on a study of
methylphenidate in 300 drug-abusing ADHD children who are in substance-abuse
treatment but are not abstinent. She expects to publish the study in 2008.
Symptoms of ADHD continue into adulthood for many children, although
hyperactivity and impulsivity often give way to inattention as the predominant
feature. Some of the adults who experience this change in ADHD signs may
benefit from continued medication, said Ashton, Gallagher, and Moore in their
report. However, they added, "... there is no information on how to
select patients for continued treatment, no experience on how long medication
should be continued, or how the drugs should eventually be withdrawn, nor
whether drug tolerance develops in adult patients."
They could find no trials of psychostimulant withdrawal in adult ADHD
patients, leaving them uncertain about how long such treatment ought to be
continued. Tolerance to methylphenidate is possible, and the drug's chemical
similarity to addictive drugs might raise concerns about withdrawal symptoms.
There is little information in the literature about withdrawal reactions,
although the small number of case reports indicates they are uncommon.
"There is insufficient evidence to give precise advice to clinicians
faced with the decision of whether to continue or discontinue drug treatment
in 18 year olds presenting with ADHD and a history of long-term
psychostimulant use," wrote the authors. They suggested that physicians
consider a trial discontinuation of psychostimulants, with dosage tapered, and
the patient closely monitored to see if adverse effects occur.
Practice standards for treating ADHD are better elaborated for children
than for adults, said Riggs. Stimulants, though, are the first treatment
choice for younger patients and work better than any behavioral therapy, she
said. New, longer-acting formulations are less abusable than are short-acting
versions and improve compliance. However, if a patient has reacted badly to
the prescribed drug or has a co-occurring anxiety disorder (which could easily
be worsened by stimulants), or if drugs did not improve symptoms, she
suggested use of a nonstimulant drug to treat the ADHD.
The choice to go off a successful psychostimulant should be carefully
discussed between doctor and patient, said Riggs. The patient should ask,"
Do I need to be on this drug for the rest of my life? Have I developed
strategies for coping without the drug?"
Patients should be taught how to track impulsivity or poor focus.
"It's important to empower patients," she said. "Then
give it a try off medications and see how they cope."
An abstract of "The Adult Psychiatrist's Dilemma:
Psychostimulant Use in Attention-Deficit/Hyperactivity Disorder" is