Tobacco exposure and impaired development: A review of the evidence

The relationship between children's exposure to tobacco and their cognitive and behavioral development is reviewed. Prenatal exposure to tobacco has clear and consistent effects on newborn neurobehavioral functioning. The extent to which these early neurobehavioral disturbances portend later impairments of cognitive functioning and academic achievement remains unclear. Inconsistent results and incomplete examination of covarying influences make it difficult to estimate the effects of tobacco on cognitive development. Research designs have not been adequately constructed to discern the extent to which the effects of prenatal exposures may be moderated by regulating postnatal environments. Studies of prenatal exposure on behavioral outcomes (such as behavior problems and Attention Deficit Hyperactivity Disorder) show a stronger link, even after control for covarying influences. The effects of prenatal tobacco exposure on attention and behavioral regulation are hypothesized to mediate the influence of tobacco on cognition and academic achievement. Animal studies of carbon monoxide and nicotine exposure strongly suggest that these toxins can adversely affect the cognitive performance and behavioral regulation of offspring exposed prenatally. Effects have been demonstrated on neuroanatomical and neurochemical structures and functions. The broad range of effects found for carbon monoxide and nicotine are consistent with the hypothesis that tobacco is neurotoxic in the developing human. MRDD Research Review 1997;3;:257–269.