On Fri, 13 Apr 2001, Jim Clark referred us to a new study showing
that a drug purported to help in Down syndrome is, in fact,
worthless.
The report is:
Lobaugh, N. et al (2001) Piracetam therapy does not enhance
cognitive functioning in children with Down syndrome.
Archives of Pediatrics and Adolescent Medicine, 155, 442--
I tracked the article down at:
http://archpedi.ama-assn.org/issues/current/rfull/poa00273.html
where it's available in full-text and pdf format.
The background is that this is yet another untested drug hyped in
the media and by parents as a miracle treatment for some
condition (usually autism, but in this case Down). I always
welcome well-designed studies, which invariably turn out to
demonstrate that the enthusiasm is entirely unwarranted (not that
it stops the hype, unfortunately).
This seemed to be the case here. The study was based on 18
children, given either placeb-->piracetam or the reverse in a
randomized, double-blind, cross-over study, and assessed with a
wide variety of measures. The authors concluded that not only
did piracetam not enhance cognition, but that it was "associated
with adverse effects". Big surprise.
But I was intrigued to discover that hidden within the study were
some interesting indications of positive effects which the
authors either minimized or overlooked.
For example, on the parent and teacher questionnaires, there were
6 items. For four of these items, there was a significant
improvement in favour of piracetam and one which just missed
significance (p < .055). These were: improvements in leadership,
fewer thought problems, increased happiness, fewer internalizing
problems, and fewer total problems. Only one contrast was poorer
for piracetam (poorer attention). These were ratings, of course,
but the they were double-blind. The authors dismissed them
as small and not clinically significant.
But there were two other indications of improvement on drug that
I noticed hidden in their data, which the authors didn't mention.
One was in their Figure 2, where they listed 78 separate tests,
reported as placebo-better or piracetam-better. I deleted two
which seemed to sit exactly on the zero point. For the remaining
76, I counted 51 which were better for piracetam.
By binomial test, I calculated that the chances of getting an
outcome this good or better by chance were only p = .002.
Secondly, they noted that in interviews with the parents (still
double-blind, I think) 11/18 reported cognitive improvement in
the child on piracetam, and only 2/18 during placebo. By Fisher
exact test, 2-tailed, the probability of this outcome if there
was no difference between paracetam and placebo is only p = .004
So I conclude that the drug was having a beneficial effect on the
kids, one which was not well-assessed by the particular tests
that they used but was noticed by the parents. Perhaps the
experimenters were just too eager to conclude otherwise.
The adverse effects, BTW, were not observed on the formal tests
or questionnaires, but were apparently spontaneous reports by the
caregivers "mostly associated with central nervous system
stimulatory effects", such as increased aggressiveness or
agitation. As these effects were seen in 7 children on the drug
and none on placebo, they're probably real.
Note: I would appreciate having someone go over my stats and my
interpretation of them. I don't feel confident I've got them
right. Heck, go over the whole paper and see if you agree with
me.
-Stephen
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Stephen Black, Ph.D. tel: (819) 822-9600 ext 2470
Department of Psychology fax: (819) 822-9661
Bishop's University e-mail: [EMAIL PROTECTED]
Lennoxville, QC
J1M 1Z7
Canada Department web page at http://www.ubishops.ca/ccc/div/soc/psy
Check out TIPS listserv for teachers of psychology at:
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