One Hit of Meth Enough to Cause 'News Defects'
By Barry Lester, Ph.D., Guest Commentary, JoinTogether.org, August 17, 2005
Recently (July 27, 2005), Medical News Today (MNT) carried a story with the alarming title, "Single prenatal dose of meth causes birth defects." Join Together, a prominent website, published a summary of the story with a similar headline and opening with the possibly more inflammatory, "Pregnant women who use methamphetamine even once put their unborn children at risk of birth defects" (July 29, 2005). These headlines misleadingly imply that the research involved women when it actually involved mice, and both the original story and the Join Together summary failed to mention that this animal research may have little if any bearing on the health outcome of humans prenatally exposed to methamphetamines.
Moreover, such reports distort our understanding of the contributions animal research can make, and can result in social policy that is not an accurate representation of what we know about how drug use during pregnancy affects children.
Animal research has always been critical for understanding human problems, in part because we can do some kinds of research with animals that we cannot do with humans. But there are also limits to applying animal findings to humans.
This is one of the lessons we learned from the hype that surrounded the media-created "crack baby" of the 1980s. The media was quick to report early animal studies suggesting that prenatal exposure to cocaine caused serious and irreversible defects in children. The first round of human studies also predicted dire consequences. But these studies were preliminary and flawed. The results of larger, well-controlled studies failed to find any of the serious defects or malformations shown by the early animal studies or human studies. The effects of cocaine were found to be far more subtle than originally anticipated.
Nevertheless, in response to this alarmist reporting, our nation became very angry with mothers who used cocaine during pregnancy and wanted them punished for harming their unborn child. Mothers were prosecuted instead of being offered treatment, and record numbers of children were removed from their biological mothers overburdening an already overburden foster-care system. Sadly, science was used to justify punitive social policy.
Unfortunately, the MNT story suggests that we are on the verge of repeating the mistakes of the 1980s with regard to prenatal exposure to methamphetamines. The actual title of the study discussed in MNT is "Methamphetamine-enhanced embryonic oxidative DNA damage and neurodevelopmental deficits." In this study, researchers from the University of Toronto injected methamphetamine directly into the membrane (peritoneum) that covers the reproductive and gastrointestinal organs in pregnant mice. The mice offspring that were produced after this direct exposure had poor motor coordination.
But what does this kind of animal research tell us about human babies? That question was addressed in March 2005 by a U.S. Department of Health and Human Services expert panel reviewing the literature on methamphetamine. They concluded that this kind of mouse study -- that uses direct injection into the peritoneum -- is not relevant to humans because pregnant women don't inject the drugs they are dependent upon into the peritoneum -- the membrane that surrounds the fetuses they are carrying.
Does that mean that this kind of research has no value? Of course not. Rather than trying to replicate human conditions, animal researchers are trying to understand the mechanism of how drugs work. So, for example, the University of Toronto investigators have now added a potentially important piece to the methamphetamine puzzle -- that because the developing fetus hasn't developed certain enzymes, it may be more vulnerable to DNA damage. Their choice of method for delivering the drug directly into the peritoneum was not based on what humans do, it was based on the method that they felt was most appropriate to test their hypothesis. The problem comes in the extrapolation of these findings to humans, and especially the leap by the media to pregnant women and birth defects in children.
Part of the problem in this case may be the University of Toronto public-affairs office. They prepared a press release claiming: "One shot of crystal meth enough to cause birth defects." And in case anyone missed the implication that this was about humans, the first sentence of the press release talks about long term neurodevelopmental problems in "babies." MNT then ran with it, re-printing the press release as if it were an actual news story. MNT offered no words of caution, failing to acknowledge limitations of the study. Join Together, as well as numerous other websites, then picked up MNT's misleading story, giving it even wider play.
The problem, however, is not the limitations of the study, nor the media alone. The bottom line is that we are all responsible -- the scientific community, policymakers, healthcare professionals, child welfare, and the legal and judicial communities -- for ensuring that public health and welfare polices are based on relevant research evidence, not press releases.
Research on the effects of prenatal exposure to methamphetamine in humans is just beginning. As with the early cocaine research, there is a body of animal studies that are finding some defects. And there are a few anecdotal reports and small, uncontrolled human studies that also report deficits in children prenatally exposed to methamphetamine. Fortunately, there is a major longitudinal multisite study underway funded by the NIH National Institute of Drug Abuse.
As a result, we will eventually have some answers. But until then, we need to prevent another "rush to judgment" in which children are labeled and stigmatized and families are destroyed based on pseudoscience. We made this mistake once already. Lets not make it again. Please.
Dr. Lester is Professor of Psychiatry and Pediatrics and Director of the Brown University Center for the Study of Children at Risk at Brown Medical School and Women and Infants Hospital in Providence, R.I.
Editor's Note: Join Together appreciates and agrees with Dr. Lester's criticism of our news summary, and we have corrected the story on our website.
This article is online at http://www.jointogether.org/y/0,2521,578073,00.html
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