The NIMH Collaborative Multisite Multimodal Treatment Study of Children
with ADHD, known as the MTA Study for short, is the largest ADHD
treatment study ever conducted. In this landmark study, 579
children carefully diagnosed with ADHD were randomly assigned to one of
four conditions:
- carefully managed and monitored medication treatment;
- intensive behavior therapy;
- the combination of careful medication treatment and behavior therapy;
and;
- routine community care.
The goal was to learn how state-of-the-art medication and behavioral
treatments compared to each other, to the combination of these
approaches, and to the care that children routinely received in
community settings. Treatments delivered by study investigators
lasted 14 months after which children received whatever treatment(s)
their parents elected. Detailed descriptions of the MTA
treatments can be found at
http://www.helpforadd.com/yr2000/janissue.htm
Outcome data at 14 months indicated that children in all groups showed
improvement relative to baseline. Although the results are
complicated and difficult to briefly summarize, children receiving
intensive medication treatment - either with or without behavior
therapy - showed significantly greater improvement in ADHD and
oppositional defiant disorder (ODD) symptoms compared to children
receiving community care or intensive behavior therapy alone.
There was also some evidence that combined treatment had benefits
beyond medication alone on certain outcomes including anxiety symptoms,
parent-child relations, teacher-rated social skills, and reading
achievement, but these were not especially strong effects.
Approximately 10 months after this initial outcome evaluation, the
initial advantage of combined treatment and medication treatment
relative to behavior therapy alone and community care was still
evident, but had dissipated by about 50%.
Detailed reports of these initial outcome studies can be found at:
http://www.helpforadd.com/yr2000/janissue.htm
http://www.helpforadd.com/2001/march.htm ,
and,
http://www.helpforadd.com/2004/june.htm
The next wave of outcome data was collected 36 months after the study
began, which was 22 months after MTA delivered treatments had
ended. Although all 4 groups continued to show improvement
relative to baseline, there were no longer significant group
differences in ADHD/ODD symptoms or other aspects of children's
functioning. Thus, there was no indication that carefully
monitored medication treatment, behavior therapy, or their combination
had benefits that persisted significantly beyond when these treatments
ended. Across all groups, between 45 and 55% of children
continued to meet diagnostic criteria for ADHD. A detailed
discussion of findings from this study can be found at
http://www.helpforadd.com/2007/august.htm
At this follow-up, researchers identified 3 classes of children who
showed distinctively different trajectories to their symptoms between
baseline and 36 months, irrespective of which group they were
originally assigned to. Class 1 (34% of the sample) showed a
gradual improvement over time. Class 2 (52%) showed a
significantly larger initial improvement that was maintained over time
and Class 3 (14%) had returned to pretreatment symptom levels following
an initially positive response. Children in Class 2 were those
who had been functioning better at baseline and who came from more
economically advantaged families.
Recently, the MTA Study group published 8-year follow-up data [MTA
Study Group, 2009. The MTA at 8 years: Prospective follow-up of
children treated for combined-type ADHD in a multisite study.
Journal of the American Academy of Child
and Adolescent Psychiatry, 48, 484-500.] At this
follow-up, data was collected on 436 of the original 579 participants
who now ranged in age from 13 to 18. The key study goals included
the following:
1. To learn whether any treatment group differences evident at the 14
and 24 month follow-up may have re-emerged now that participants were
adolescents.
2. To learn whether the different trajectories identified at the prior
follow-up predicted outcomes in subsequent years, and,
3. To compare the functioning of MTA adolescents relative to their
non-ADHD peers on a variety of important outcomes. Twenty-one
different outcomes were examined, including core ADHD symptoms, ODD
symptoms, antisocial behavior, various indices of academic achievement,
social functioning, depression, anxiety, and other psychiatric
problems. The comparison peers were 289 children recruited 24
months into the study from the same schools study children attended.
-
Results
-
1.
Did any benefits of MTA treatments
re-emerge in adolescence?
The answer to this question is an unqualified no. Of the over 20
outcomes examined not a single significant difference based on initial
random assignment was found. The general pattern was for any
initial group difference to converge over time and for children in all
groups to maintain improvement relative to baseline.
2.
Was continued medication use
associated with better outcomes?
Past year medication use at the 8-year follow-up was not associated
with better outcomes in any area except for math achievement.
Thus, there was scant evidence that medication treatment - at least as
provided in community settings - was associated with better adolescent
outcomes.
It is interesting to note that only 32.5% of participants had received
medication over 50% of days during the past year compared nearly twice
this figure, 63.3%, at the initial 14-month follow-up. Thus,
there was a steady decline in medication use over time.
3.
Did the classes of symptom
trajectories identified at 36 months predict outcomes in adolescence?
In general, yes. Children in Class 2 - those with the best
initial treatment response - continued to fare better over time than
children in classes 1 or 3. Thus, differences in children's
initial response to treatment - regardless of whether that treatment is
medication or behavior therapy - tended to predict longer term outcomes
as well.
4.
How were children with ADHD faring
in comparison to peers without ADHD?
Although children with ADHD had shown significant improvement since
their original diagnosis, they were still impaired in most areas
relative to peers. In fact, for 19 of the 21 specific outcomes
tested, adolescents in the ADHD group were doing significantly
worse. This was true even though only about 30% of MTA
participants still met full diagnostic criteria for ADHD.
About 25% of MTA youth were displaying clinically significant
antisocial behavior (vs. just 5 % of comparison youth) with roughly 27%
having been arrested at least (compared to 14% of peers). MTA youth had
significantly lower grades, were about twice as likely to have repeated
a grade (37% vs. 19%), and score about 0.5 standard deviations lower on
academic achievement testing.
-
Summary and
Implications -
The key findings from this study are as follows:
1. Any initial benefits of intensively delivered medication treatment
and behavior therapy relative to routine community care do not persist
significantly beyond when those treatments were administered.
2. The trajectory of ADHD symptoms in childhood - and how children
initially respond to treatment - is a good predictor of adolescent
outcomes. Specifically, children whose ADHD symptoms show the
best initial response are likely to maintain better outcomes in many
areas over time.
3. Despite overall gains relative to baseline for all study groups, and
even though only 30% of MTA youth continued to meet ADHD diagnostic
criteria in adolescence, they were still functioning significantly less
well than comparison peers. Thus, the adverse long-term outcome
of childhood ADHD was clearly substantiated.
What are the important clinical implications of these findings?
Some have suggested that because no long-term benefit of medication
treatment was found, there is little value in this treatment.
This does not seem like a reasonable conclusion, however, as benefits
of carefully monitored medication treatment were initially found but
those benefits do not last much beyond when this treatment is in
place. It is possible that if careful oversight of medication
treatment had been maintained across all 8 years, continued advantages
would have been found. However, as the authors note, this is mere
speculation and it may not even be possible to maintain adherence to a
carefully monitored medication treatment program over this time frame.
It is also evident that even though core ADHD symptoms may remit over
development to the point that full diagnostic criteria for ADHD are no
longer met, many youth will continue to struggle in multiple
areas. This highlights the importance of carefully attending to a
youth's overall functioning - and not just ADHD symptoms - in
determining the need for ongoing treatment, and to make sure that
treatments delivered specifically address the areas where functioning
is compromised.
Perhaps the most important implication - as the authors emphasize - is
the extent to which findings highlight the crucial need for developing
treatments that are "...efficacious, accessible, and lasting for high
school-aged youths with ADHD and their parents". They note that
teenagers with ADHD are not easy to treat, even though the numerous
outcome differences between MTA youth and comparison peers highlights
the frequent need for ongoing treatment.
While medication may be one component of effective treatment, adherence
to medication treatment in adolescence is notoriously poor and other
approaches clearly need to be developed. The authors suggest that
motivational approaches to "...encourage adolescent participation in
nonpharmacological interventions...and that also address continued
family and school involvement."
Clearly, it is time to move beyond the strong emphasis on studies of
medication treatment and behavior therapy for ADHD, as maintaining
adherence to behavior therapy in multiple settings is also exceedingly
difficult. In fact, one of the many very important contributions made
by the MTA Study is highlighting the limitations of medication and
behavioral treatments for ADHD, as this will hopefully expand serious
scientific study of alternative treatment approaches.
Fortunately, as recently published studies of neurofeedback, working
memory training, and other approaches suggest, this is already
beginning to happen. Lets hope it continues.