Research Findings - Research on AIDS and Other Medical Consequences of Drug Abuse - Non-AIDS Research

Relation of Coronary Artery Calcium to Left Ventricular Mass in African-Americans

Both coronary artery calcium (CAC) deposits and increased ventricular (LV) mass are important risk factors for coronary heart disease, but the relation between these two factors has rarely been studied. The investigators (Dr. Shenghan Lai and his colleagues at Johns Hopkins) examined the correlation of coronary artery calcium and left ventricular mass in 159 young to middle-aged African-Americans, and found that the average left ventricular mass indices were bigger in the CAC-positive groups than in CAC-negative groups in both genders [p=0.0004 in men and p=0.08 in women]. Studies are in progress to examine if drug abuse (e.g., cocaine) has an impact on cardiovascular disease (coronary artery calcium/ventricular function) in African-Americans. Tong, W., Lima, J.A., Lai, H., Celentano, D.D., Dai, S. and Lai, S. Am J. Cardiol., 93, pp. 490-492, 2004.

Assessment of Neurobehavior in Drug-Exposed and High-Risk Infants

A recently-published supplement to the journal Pediatrics provides information and data for the Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS). The NNNS was developed to assess the neurobehavior of drug-exposed and high-risk infants, as part of the multisite, prospective longitudinal study of in-utero drug exposure, the Maternal Lifestyle Study (MLS). MLS has been jointly-supported by NICHD and NIDA since it began in the early 1990s. The NNNS was developed because of a concern that existing instruments were not sensitive to the neurobehavioral effects of prenatal drug exposure and for infants at risk. The Pediatrics supplement provides the rationale for the NNNS and its procedures. It also includes NNNS data from the MLS and from a low-risk term sample, as well as a discussion of clinical uses. Lester, B.M., and Tronick, E.Z. (Eds.). The Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS). Pediatrics, 113(3), pp. 631-699, 2004.

Severity of Prenatal Cocaine Exposure and Child Language through Age 7 Years

Results of data analyses from a longitudinal cohort study at the University of Miami suggest that greater severity of prenatal cocaine exposure is associated with increased (although modest) deficits in aptitude for language performance, but not with a trajectory of language development through 7 years of age. Within the framework of the latent growth curve analysis utilized, the intercept of the language growth curve was interpreted as reflecting a relatively time-invariant aptitude for language performance, and the slope was interpreted as indicating a time-varying trajectory of language performance. Language was assessed at ages 3, 5, and 7 years. The observed association was independent of multiple other possible sources of variation in language development, including the child's intellectual functioning and language stimulation in the home. Severity of prenatal cocaine exposure was characterized using a construct combining maternal self-report of cocaine use during pregnancy with maternal and infant bioassays. The statistical analytical model included gender, and prenatal alcohol, tobacco, and marijuana among the covariates. The researchers note that although the study has many strengths, the sample is relatively homogeneous (e.g., full-term, relatively healthy African-American children residing in socially disadvantaged inner-city neighborhoods), and caution should be exerted in generalizing the cocaine-language estimate to other populations or settings. Furthermore, they call for further investigation in other scientifically rigorous studies with sufficient sample sizes, in order to understand mechanisms by which prenatal cocaine exposure may affect child language functioning. Bandstra, E.S., Vogel, A.L., Morrow, C.E., Xue, L., and Anthony, J.C. Severity of Prenatal Cocaine Exposure and Child Language Functioning Through Age Seven Years: A Longitudinal Latent Growth Curve Analysis. Substance Use and Misuse, 39(1), pp. 25-59, 2004.

Relationships between Marijuana Exposure and Response Inhibition in 18-22 Year-Olds

Researchers from the Ottawa Prenatal Prospective Study (OPPS) have reported initial fMRI results in an investigation of the effects of prenatal exposure to marijuana, and current use of marijuana, on response inhibition in 18-22 year-old study participants. OPPS participants have been assessed longitudinally on behavioral outcomes at multiple times since birth. Those who were prenatally-exposed to marijuana have been found to show differential performance, relative to non-exposed participants, on an aspect of executive functioning that involves inhibition of prepotent responses. In light of literature showing associations between executive functioning and maturation of the prefrontal cortex, the purpose of the fMRI analyses was to examine the putative association between prefrontal cortex activity of young adults and prenatal exposure to marijuana. fMRI analyses were also carried out relative to current marijuana use among the study participants. Thirty-five OPPS subjects were imaged using a 1.5 T Siemens MR scanner. A go/no go task was used to measure response inhibition. Results suggest that both prenatal exposure and current use were related to neurophysiological aspects of response inhibition. Prenatal marijuana exposure was most related to increased activity in left dorsolateral-prefrontal-cortex (DLPFC), and attenuated right DLPFC activity. Current marijuana use was most associated with right DLPFC activity. This is the first report of fMRI data relative to response inhibition in young adults prenatally exposed to marijuana. These investigators are continuing their fMRI explorations in this cohort. Smith, A., Fried, P., Hogan, M., and Cameron, I. The Effects of Prenatal and Current Marijuana Exposure on Response Inhibition: A Functional Magnetic Resonance Imaging Study. Brain and Cognition, 54(2), pp. 147-149, 2004.