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Medication:
The smart-pill oversell
Evidence
is mounting that medication for ADHD doesn't make a lasting difference to
schoolwork or achievement.
12 February 2014
Ben
Harkless could not sit still. At home, the athletic ten-year-old preferred
doing three activities at once: playing with his iPad, say, while watching
television and rolling on an exercise ball. Sometimes he kicked the walls;
other times, he literally bounced off them.
School
was another story, however. Ben sat in class most days with his head down on
his desk, “a defeated heap”, remembers his mother, Suzanne Harkless, a social
worker in Berkeley, California. His grades were poor, and his teacher was at a
loss for what to do.
Harkless
took Ben to a therapist who diagnosed him with attention deficit hyperactivity
disorder (ADHD). He was prescribed methylphenidate, a stimulant used to improve
focus in people with the condition.
Harkless
was reluctant to medicate her child, so she gave him a dose on a morning when
she could visit the school to observe. “He didn't whip through his work, but he
finished his work,” she says. “And then he went on and helped his classmate
next to him. My jaw dropped.”
ADHD
diagnoses are rising rapidly around the world and especially in the United
States, where 11% of children aged between 4 and 17 years old have been
diagnosed with the disorder. Between half and two-thirds of those are put on
medication, a decision often influenced by a child's difficulties at school.
And there are numerous reports of adolescents and young adults without ADHD
using the drugs as study aids.
As
the drugs have become more widespread, so has their cultural cachet. Stimulant
medications have gained a reputation for turbo-charging the intellect. Even
news stories critical of their use refer to them as “good-grade pills”,
“cognitive enhancers” and “mental steroids”.
For
most people with ADHD, these medications — typically formulations of methylphenidate
or amphetamine — quickly calm them down and increase their ability to
concentrate. Although these behavioural changes make the drugs useful, a
growing body of evidence suggests that the benefits mainly stop there. Studies
indicate that the improvements seen with medication do not translate into
better academic achievement or even social adjustment in the long term: people
who were medicated as children show no improvements in antisocial behaviour,
substance abuse or arrest rates later in life, for example. And one recent
study suggested that the medications could even harm some children1.
After
decades of study, it has become clear that the drugs are not as transformative
as their marketers would have parents believe. “I don't know of any evidence
that's consistent that shows that there's any long-term benefit of taking the
medication,” says James Swanson, a psychologist at the University of
California, Irvine.
Now
researchers are trying to understand why. The answer could lie in sub-optimal
use of the drugs, or failure to address other factors that affect performance,
such as learning disabilities. Or it could be that people place too much hope
on a simple fix for a complex problem. “What we expect medication to do may be
unrealistic,” says Lily Hechtman, a psychiatrist at McGill University in
Montreal.
Unrealistic expectations?
In
1937, psychiatrist Charles Bradley noticed that problem children treated with a
stimulant, benzedrine sulphate, became quieter, better behaved and more
studious. Since then, studies have repeatedly demonstrated that stimulant
medications reduce the core symptoms of ADHD, which include incessant,
disruptive activity coupled with a lack of reflectiveness and inhibition.
Stimulants work by increasing levels of the neurotransmitter dopamine in the
brain, affecting regions involved in focus, self-control and the sense that an
activity is rewarding. They take effect immediately, and they help as many as
80% of those with ADHD — one of the best response rates for a psychiatric drug.
Years
of lab and classroom studies attest that the medications help affected children
to perform in school. Treated children fidget less. They do better on
laboratory tests requiring concentration and short-term memory. And they take
better notes and hand in more homework, making fewer careless mistakes. Nora
Volkow, director of the National Institute on Drug Abuse in Bethesda, Maryland,
says that these benefits carry over into the real world, at least in the short
term. “They help you pay attention,” she says. “The grades do improve.”
SOURCE:
IMS HEALTH/S. P. HINSHAW & R. M. SCHEFFLER THE ADHD EXPLOSION: MYTHS,
MEDICATION, MONEY, AND TODAY'S PUSH FOR PERFORMANCE (OXFORD UNIV. PRESS, IN THE
PRESS)
But
the few studies that have examined the effects of ADHD medication much beyond a
year have found that the benefits either vanish or shrink to clinically
meaningless proportions.
In
the early 1990s, as rates of stimulant prescriptions were beginning to climb,
the National Institute of Mental Health in Bethesda, Maryland, funded a study
to compare different treatments for the disorder. Known as the Multimodal
Treatment Study of Children with ADHD, or MTA, the study randomized 579
children aged between seven and ten with ADHD to receive one of four
treatments: stimulant medication, behaviour therapy, medication and behaviour
therapy combined or whatever care they had already been receiving.
After
14 months, the groups treated with medication alone and medication plus
behaviour therapy showed greater improvements in core ADHD symptoms than the
other two groups. For academic achievement, only the group receiving medication
and behaviour therapy combined outperformed the group receiving regular care2. By three years in, the four groups had
become indistinguishable on every measure3. Treatment conferred no lasting benefit
in terms of grades, test scores or social adjustment. Eight years later, it was
the same story4. “Nothing we did could tease out and say
there's a long-term effect,” says Swanson, who was one of the lead
investigators on the MTA.
The
MTA's findings are borne out in most of the studies that followed students for
long periods of time. A literature review in 2012, which included studies that
tracked children with ADHD for three years or more, found little evidence for a
significant effect on standardised-test scores, grades or on the likelihood
that a student would be held back a year5. A 2013 review of randomized controlled
trials longer than 12 months similarly concluded that there is scant evidence
for improvements in ADHD symptoms or academic performance lasting much beyond a
year6.
There
is even some evidence that ADHD medication could worsen outcomes. In 2013, a
team of economists published a study1 examining the effects of a policy change
in Quebec that resulted in thousands of children being given prescriptions for
methylphenidate. The authors found that children who began taking it actually
did worse at school and were more likely to drop out than those with similar
levels of symptoms who did not receive drugs. Girls taking the drug had more
emotional problems, and both sexes reported worse relationships with their
parents.
There
are a few studies that do show long-term gains in academic performance, but the
boost is not large. A study that tracked 594 students aged 5–11 with ADHD found
that those using medication for at least a year scored 3 points out of 100
higher on standardized maths tests and 5 points higher on reading tests than
those not taking medication7. But this was not enough to close the
test-score gap between those with ADHD and those without. And the gains faded
over time even if the children stayed on the drugs, according to study
co-author Stephen Hinshaw, a psychologist at the University of California,
Berkeley.
Related
stories
In
2012, a study in Iceland — the only country where rates of stimulant medication
use are comparable to those of the United States — found that although the
scores of all children with ADHD declined, on average, on standardized maths
tests between the ages of 9 and 12, those of students who started medication
earlier during that period declined less than those who waited longer to start8.
It
is possible that there are long-term benefits that studies so far have not
captured. But given the abundance and consistency of the data, the drugs cannot
be doing much for most of the millions of children who take them, says Alan
Sroufe, a psychologist emeritus at the University of Minnesota in Minneapolis.
“If they were, it wouldn't be hard to detect.”
Puzzling paradox
Researchers
are beginning to address this paradox. How can medication that makes children
sit still and pay attention not lead to better grades?
One
possibility is that children develop tolerance to the drug. Dosage could also
play a part: as children grow and put on weight, medication has to be adjusted
to keep up, which does not always happen. And many children simply stop taking
the drugs, especially in adolescence, when they may begin to feel that it
affects their personalities. Children may also stop treatment because of side
effects, which can include difficulty sleeping, loss of appetite and mood
swings, as well as elevated heart rate.
Or
it could be that stimulant medications mainly improve behaviour, not intellectual
functioning. In the 1970s, two researchers, Russell Barkley and Charles
Cunningham, noted that when children with ADHD took stimulants, parents and
teachers rated their academic performance as vastly improved9. But objective measurements showed that
the quality of their work hadn't changed. What looked like achievement was
actually manageability in the classroom. If medication made struggling children
appear to be doing fine, they might be passed over for needed help, the authors
suggested. Janet Currie, an economist at Princeton University in New Jersey,
says that she might have been observing just such a phenomenon in the Quebec
study that found lower achievement among medicated students1.
And
it may simply be that drugs are not enough. Stimulant medications have two core
effects: they help people to sustain mental effort, and they make boring,
repetitive tasks seem more interesting. Those properties help with many school
assignments, but not all of them. Children treated with stimulants would be
able to complete a worksheet of simple maths problems faster and more
accurately than usual, explains Nora Volkow. But where flexibility of thought
is required — for example, if each problem on a worksheet demands a different
kind of solution — stimulants do not help.
Beyond belief
In
people without ADHD, such as students who take the drugs without a prescription
to help with school work, the intellectual impact of stimulants also remains
unimpressive. In a 2012 study of the effects of the amphetamine Adderall on
people without ADHD, psychologists at the University of Pennsylvania in
Philadelphia found no consistent improvement on numerous measures of cognition,
even though people taking the medication believed that their performance had
been enhanced10.
Increased
focus has benefits, say some experts, but many children with ADHD need help in
more areas if they are to succeed at school. “Many things go into grades,” says
Joshua Langberg, a psychologist at Virginia Commonwealth University in
Richmond. “One of those is certainly a child's behaviour and ability to focus,
which medication does a nice job of improving. But they also include a child's
basic abilities in math and reading, their IQ and their ability to manage time
and plan. It's not clear why we would expect medication to impact those
things.”
“Only
one in four kids are getting anything close to what we would say is good
treatment.”
Some
researchers think that the lack of evidence for long-term academic benefits is
a result of flawed study design. Peter Jensen, a leader on the MTA study, says
he believes that if the children had been maintained on the study's protocol,
the initial gains they made would have lasted. Longer randomly controlled
trials would be challenging both from a technical and ethical standpoint, but
the suggestion highlights another problem, namely the discrepancy between the
optimal care given during a trial and that which most children receive.
After
the 14-month, randomized trial period, participants in the MTA study began to
receive what Jensen calls treatment 'in the community'. He says it is typically
of low quality. Few doctors monitor children closely enough to arrive at
optimal dosage or identify and treat co-occurring conditions — such as
depression and anxiety — that affect up to 70% of children with ADHD. “Only one
in four kids are getting anything close to what we would say is good
treatment,” Jensen says.
When
the MTA team examined the follow-up data, it found that many non-medical
factors play a big part in whether improvements last. The best predictor of a
child's response to treatment wasn't which treatment they were assigned, but a
cluster of factors that were present at the start. Children with more
advantages — higher intelligence, better social skills, intact families, higher
parental education, fewer conduct problems or higher socioeconomic status —
were likely to make big strides and hold onto them no matter what the treatment
was, whereas children without these advantages typically progressed more slowly
and regressed after treatment stopped2, 3, 4.
But
disadvantaged children benefited when they received both medication and
behaviour therapy. “The kids with the most problems needed the combination,”
says Jensen, who adds that parents should have easier access to proven
behaviour therapies. The effects of behavioural treatment don't seem to be
longer-lasting than those of medication, however: once active treatment stops, they
dissipate.
Future
studies might explore whether medication offers subtle benefits that are not
reflected in test scores or grades. Many researchers think that a stint on
medication, when it is needed, can create an upward spiral of self-esteem that
may make a crucial difference to a child's life — but there are no hard data to
support this. “It may be that treatment doesn't translate into better grades”
in the long term, Volkow says. “But what I'd like to see is, are those kids
overall better integrated?”
Some
experts think that the focus on academic achievement is misguided — that the
point of the drugs has never been to improve children's grades, or increase
their chances of admission to the best universities. “Medications are given for
their short-term effects,” says Swanson. “Don't expect medication to get rid of
every problem a child has. But if the problem right now is not passing the
second grade, or not having any friends in the third grade, we can do something
about that now.”
Some
parents seem to understand that. Suzanne Harkless says that her hopes for
medication are modest. She wants to keep Ben engaged in the fifth grade while
she looks for a middle school that might provide him with the structure he
needs. “My goal right now is not to get him into a good college,” she says. “My
goal is to keep him in school.”
Other
parents may pin unrealistic hopes on these drugs as their use goes up around
the world (see 'Popular prescriptions'). “Competition in today's
global economy is fuelling the dramatic increase in the use of ADHD
medications, especially in the United States,” says Richard Scheffler, a health
economist at the University of California, Berkeley, and co-author of a
forthcoming book with Hinshaw on the growing popularity of ADHD drugs.
For
Currie, the question comes down to transparency. “Parents do care about how
their children are doing in school,” she says. “It's misleading to tell parents
that this will help their children succeed, when there's no evidence that it's
the case.”
- Currie, J., Stabile, M.
& Jones, L. E. National Bureau of Economic Research Working Paper
19105 (NBER, 2013); available at http://www.nber.org/papers/w19105
- MTA Cooperative Group Arch.
Gen. Psychiatry 56, 1073–1086 (1999).
- Jensen, P. S. et al. J.
Am. Acad. Child Asolesc. Psychiatry 46, 989–1002 (2007).
- Molina, B. S. G. et al.
J. Am. Acad. Child Adolesc. Psychiatry 48, 484–500 (2009).
- Langberg, J. M. & Becker,
S. P. Clin. Child Fam. Psychol. Rev. 15, 215–233 (2012).
- Parker, J. et al. Psychol.
Res. Behav. Manag. 6, 87–99 (2013).
- Scheffler, R. M. et al.
Pediatrics 123, 1273–1279 (2009).
- Zoëga, H. et al. Pediatrics
130, e53–e62 (2012).
- Barkley, R. A. & Cunningham,
C. E. Clin. Pediatr. 17, 85–92 (1978).
- Ilieva, I., Boland, J. &
Farah, M. J. Neuropharmacology 64, 496–505 (2013).