A study of children who were prenatally exposed to methamphetamine, published online by the journal Pediatrics in March, prompted alarming headlines that recalled the “crack baby” panic of the 1980s and ’90s. “ ‘Meth Babies’ Show More Behavior Problems,” the Chicago Tribune announced. “Mom’s Meth Use During Pregnancy Causes Kids’ Behavioral Problems,” reported CBS News.
But just as the warnings about “crack babies” handicapped for life by their mothers’ drug use turned out to be wildly overblown, there was less to this study than the press coverage suggested. The researchers, led by Brown University psychologist Linda LaGasse, claimed to have identified “an important public health problem” that could “place tremendous burdens on society” based on small differences in test scores that may not even have been caused by meth exposure.
LaGasse and her colleagues administered a test called the Child Behavior Checklist (CBCL) to 330 children, half of whom were born to mothers who had used meth during pregnancy. Over all, the scores of the exposed and nonexposed kids, who were tested at ages 3 and 5, were virtually indistinguishable. The researchers focused on a few subscales where there were statistically significant differences, ranging from slightly less than a point to slightly more than a point.
“Because CBCL findings are based on caregiver report,” the authors conceded, “there could be reporting bias.” In other words, the mothers or other caregivers who answered the questionnaires on which the scores were based may have been more inclined to perceive and report problems precisely because they worried about the potential damage caused by meth exposure.
LaGasse et al. tried to control for various possible confounding variables—factors associated with meth use that might independently explain the results. But they conceded that “our measure of child abuse through caregiver report of Child Protective Services involvement likely underestimates abuse.” Likewise, their measure of “caregiver psychological symptoms,” which were associated with children’s behavior problems, may not have captured all of the relevant differences between women who use meth when they’re pregnant and women who don’t.