|Toddlers of Mothers Who Smoked During Pregnancy
Show Behavior Problems
Study Supported by National Institute on Drug Abuse First to Show
Washington — New findings from a study supported by the
National Institute on Drug Abuse (NIDA), National Institutes of
Health suggest that toddlers of women who smoked during pregnancy
begin to show a pattern of behavior problems as early as 18-24 months
of age. It is the first study to show a link between smoking during
pregnancy and child behavior problems in the first years of life.
“We already know that smoking can negatively affect the physical
health of children,” said Elias A. Zerhouni, M.D., NIH Director. “This
study tells us we should also be taking a closer look at how it
affects development and behavior.”
“This study highlights the importance of better understanding
how prenatal exposure to nicotine affects the development of the
fetal brain, and how in turn this disrupts behavior later on in
childhood and adolescence,” said Nora Volkow, M.D., NIDA Director. “If
we can pinpoint what areas of the brain might be most affected
by prenatal cigarette smoke exposure, we can better tailor prevention
or remedial intervention while children are very young.”
The researchers followed 93 toddlers between their first and second
birthdays. Forty-seven percent were prenatally exposed to cigarettes.
First, researchers examined whether exposed toddlers’ behavior
patterns differed over time from non-exposed toddlers. Then they
tested if cigarette exposure was associated with specific types
of disruptive behavior.
The study was designed to delineate between the normal behavior
patterns typically seen in the “terrible twos” and more severe
behaviors. The researchers found that toddlers exposed to cigarette
smoke in utero exhibited higher levels of behavior problems
from 12 through 24 months. The level of behavior problems remained
relatively stable over time for the non-exposed toddlers, but for
the exposed toddlers the problems increased from 18 to 24 months.
Additionally, researchers found that nearly all toddlers with behavior
problems in the clinical range at age 2 had been exposed to cigarette
smoke. They also found that exposure to cigarette smoke was associated
with disruptive social behavior. Exposed toddlers were significantly
more likely to exhibit aggressive behavior and to stubbornly refuse
to follow directions. They were also less likely to seek out and
participate in playful social interactions with their mothers.
Researchers also found that exposure to cigarette smoke was associated
with social, rather than emotional aspects of early disruptive
behavior. For instance, compared to non-exposed toddlers, exposed
toddlers were significantly more likely to exhibit aggressive behavior
and to stubbornly refuse to follow directions. They were also less
likely to seek out and participate in playful social interactions
with their mothers. They were not more likely to have difficulty
regulating negative emotion.
"Research into the relationship between prenatal smoking and toddler
behavior adds a complex new dimension to our portfolio of knowledge
of the deleterious effects of smoking,” said Vice Admiral Richard
Carmona, United States Surgeon General.
This study does not prove whether or not prenatal exposure to cigarettes
causes behavior problems, but it does bring us closer to understanding
how that exposure affects fetal brain systems that regulate behavior.
The study is being published in the July/August issue of the journal
Child Development. The finding comes from a study funded by NIDA
and conducted by Lauren Wakschlag, Ph.D., and her colleagues at the
University of Illinois at Chicago, in collaboration with researchers
at the Universities of York (England) and Massachusetts (Boston),
and the National Institute of Mental Health.
The National Institute on Drug Abuse is a component of the
National Institutes of Health, U.S. Department of Health and
Human Services. NIDA supports most of the world's research on
the health aspects of drug abuse and addiction. The Institute
carries out a large variety of programs to ensure the rapid dissemination
of research information and its implementation in policy and
practice. Fact sheets on the health effects of drugs of abuse
and further information on NIDA research can be found on the
NIDA web site at http://www.drugabuse.gov.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.