Prenatal Cocaine Exposure: The Effects

Prenatal cocaine exposure has significant effects on both behavior and brain functioning.  In animal studies, prenatal cocaine exposure during development in the womb causes disruptions in brain development and causes adverse effects on behavior in childhood that lasts through adulthood.  Similar studies in human populations have been limited due to ethical concerns.  The research that has been done regarding prenatal cocaine exposure in human populations have shown impairments in the attention, impulse control and emotion regulation portions of the brain, along with a heightened predisposition to initiate substance abuse.

Researchers from the Yale School of Medicine, headed by Dr. Rajita Sinha, had conducted a study to evaluate the grey matter of adolescents who had prenatal cocaine exposure in comparison to those who did not have prenatal cocaine exposure.  The researchers had surmised that adolescence is the time period in life when substance use begins.  The study was published in the June edition of Biological Psychiatry.

Forty-two adolescents between the ages of fourteen and seventeen were recruited for this particular study.  These adolescents had prenatal cocaine exposure and were part of a long-term study.  For comparison, twenty-one adolescents that were not exposed to cocaine in utero were also studied.  All participants were asked questions about their use of a wide range of illegal drugs, submitted urine samples and underwent structural neuroimaging scans.

The results of the study showed those adolescents subjected to prenatal cocaine exposure had lower gray matter volume in key brain areas associated with emotion, reward, memory and executive functioning, in comparison with those adolescents with no prenatal cocaine exposure.  Also of note was the volume of gray matter between those that had prenatal cocaine exposure and those adolescents with no prenatal cocaine exposure in the womb.  With each one milliliter decrease in brain matter, there was an increase of initiation of substance abuse by 69.6% to 83.6% depending on the region of the brain affected.

According to Dr. John Krystal, editor of Biological Psychiatry, The results of this study of prenatal cocaine exposure contain strong implications for those pregnant women who use cocaine.  Prenatal cocaine exposure may cause brain regions to develop abnormally even though structurally the brain may look normal.  The gray matter of the brain is the part of the nervous system that processes information.  Deficits in gray matter areas are documented in many other disorders such as schizophrenia and attention deficit disorders, among others.

The researchers of this study have noted, however, that participants in this study differed only in whether there was prenatal cocaine exposure; no other health or mental illnesses were noted in participants.  In the broadest scope, this study shows how prenatal cocaine exposure in the womb may translate to brain changes that impact emotion and cognition.  Dr. Sinha predicts that in the future the specific brain alterations that are a result of prenatal cocaine exposure may serve as biomarkers that can be targeted to prevent drug use and abuse.