Source: New Scientest
Section: Letters
Pubdate: 4 April 1998
Contact:   http://www.newscientist.com/ns/lettersreply.html
Website: http://www.newscientist.com/

HIGH ANXIETIES

Like the premature reports of Mark Twain's death, New Scientist's report of
the alleged "suppression" by the WHO of our paper comparing the health
effects of cannabis with those of alcohol, opiates and tobacco has been
greatly exaggerated (This Week, 21 February, p 4). 

Our paper is being prepared for publication later this year (along with the
other background papers) by the Addiction Research Foundation and the WHO. 

The content of our paper was not reflected in the WHO report because some
of the experts who were consulted by the WHO in the process of peer
reviewing the report believed that there were too many uncertainties about
the adverse health effects of cannabis to permit such comparisons to be
made. These uncertainties were acknowledged in our paper, but we undertook
the comparison because of its public health policy significance. 

The fact that on current patterns of use, cannabis is a lesser public
health problem than alcohol and tobacco does not mean that cannabis use is
harmless or that its public health consequences are trivial. 

The comparison emphasises the unacceptable burden of disease and disability
that alcohol and tobacco cause in much of the developed and developing world. 

Finally, the disagreement between the experts about the validity of
comparisons of the adverse health effects should not detract from the fact
that they were agreed on the adverse health effects of cannabis summarised
in the report. They also agreed on the priorities for future research that
would enable us to better understand the adverse health effects of cannabis
use. 

WAYNE HALL 
National Drug and Alcohol Research Centre Sydney
ROBIN ROOM 
Addiction and Mental Health Services Corporation Toronto, Canada

THE EDITOR REPLIES: 
New Scientist was aware that a background paper comparing cannabis with
alcohol and tobacco is to be published later this year. If anything, this
adds to our suspicions about the WHO's decision to exclude the comparison
from its report. If the comparison is good enough to publish as a
background paper, why not include it in the report? Part of the answer is
that reports are widely circulated and read by policy makers and
journalists, whereas background papers are not. 

If "uncertainties" were the only reason for excluding the analysis, one
must question the consistency of the peer review process. Much of the
material deemed fit to include in the report could scarcely be described as
certain. Take one example, the hormonal effects of cannabis. Here the
report says: "This action of cannabis might be of importance in the
prepubertal male... however, at present this is purely conjecture." 

© Copyright New Scientist, RBI Limited 1998