With the arrival of the relatively inexpensive and smokable crack form of cocaine, the rate of newborns exposed to cocaine in utero rose dramatically in the early 1990s. In the mid-1990s it was estimated that 1.1% of pregnant women used crack cocaine. Early reports of neonatal behavioral abnormalities led to the label “crack baby syndrome” and were followed up with several large, longitudinal studies. Crack cocaine–exposed neonates were demonstrated to be more jittery and less likely to modify their attentional behavior based on their arousal state. During the first year, infants exposed prenatally to crack cocaine are rated as having more attentional abnormalities and being less successful at remembering stimuli in their environments. However, the term crack baby syndrome is now generally recognized as inappropriate beyond the early neonatal period, after which time the behavioral differences are more subtle and do not constitute a distinct syndrome.
Several large-scale studies were funded to follow crack cocaine–exposed babies over time. They found that the mothers who had used crack cocaine during pregnancy were different from pregnant women recruited from similar economic and ethnic/racial groups. The mothers of the cocaine-exposed infants were (1) more likely to have used alcohol, cigarettes, and marijuana during pregnancy; (2) were more likely to continue to use alcohol and drugs of abuse postnatally; and (3) were more likely to have symptoms of psychiatric distress prenatally/postnatally. These polysubstance use and psychological characteristics of crack cocaine–using women have been repeatedly documented and found to have their own negative effects on child development.
One question addressed by these studies is to what degree are any persistent difficulties seen due to the cocaine exposure itself, not the other risk factors. In regards to overall mental functioning in early childhood, some studies found small effects of the cocaine specifically and others found no effect. However, specific effects of cocaine exposure on global functioning reported in infancy were no longer detectable, or subtle, by school age.
However, several studies have shown that cocaine exposure is associated with disruptions in attention and inhibition that could not be attributed to differences in maternal functioning and exposure to other substances. These independent relations of cocaine exposure on attention and inhibition have been confirmed in animals and persist into school age. In particular, the difficulties seem to be in paying attention to the information that is important in the moment and using that information to reach goals, as opposed to acting impulsively. Unfortunately, the attentional and planning abilities that are particularly sensitive to crack cocaine are also vulnerable to alcohol, cigarette, and marijuana use during pregnancy. So although the specific effect of the cocaine may be small, crack cocaine–exposed children usually are exposed to multiple substances that all impact on the same system.
Although it may not ameliorate the effects of cocaine on attention, positive environments have been shown to reduce the rate of mental retardation and increase verbal IQ in cocaine-exposed children. The hopeful findings of researchers is that providing a home life supportive of mental development makes a substantial impact on how crack cocaine–exposed children are doing as they enter school age.
References:
- Bendersky, , Gambini, G., Lastella, A., Bennet, D. S., & Lewis, M. (2003). Inhibitory motor control at five years as a function of prenatal cocaine exposure. Journal of Developmental Behavioral Pediatrics, 24, 345–351.
- Harvey, A., & Kosofsky, J. A. (Eds.). (1998). Cocaine: Effects of the developing brain. Annals of the New York Academy of Sciences, 846.
- National Clearinghouse for Drug and Alcohol Abuse Information, http://www.health.org
- National Institute of Drug Abuse of the National Institute of Health, http://www.drugabgov
- Singer, T., Minnes, S., Short, E., Arendt, R., Farkas, K., Lewis, B., et al. (2004). Cognitive outcomes of preschool children with prenatal cocaine exposure. Journal of the American Medical Association, 291, 2448–2456.