Marijuana is the most commonly used illegal drug, and it is frequently used by adolescents during a time when substantive developmental changes are taking place in the brain. Therefore, its effects on brain structure and function are of considerable importance. It is well established that acute administration of marijuana has significant behavioral and physiological effects. However, data to support chronic and/or residual changes are more elusive. We have collected MRI and CBF data on 57 marijuana users. MRI scans were used to determine brain volume measurements. These data indicate significant differences in gray matter volume related to the age when marijuana was first used. Early users have significantly smaller gray matter volume compared to later users. In the proposed project, we will study two groups of marijuana smokers, those who started using marijuana before age 15 and those who started smoking after age 18, and compare them to drug-naïve normal controls. Exclusion of drug use in controls is difficult but essential in testing the hypotheses. We will compare subjects on volume estimates of gray and white matter in cortical and subcortical structures obtained with MRI, neuropsychological testing and measurement of cerebral blood flow obtained with Positron Emission Tomography (PET), while performing an activation task.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA011775-04
Application #
6515628
Study Section
Special Emphasis Panel (ZRG1-BDCN-5 (01))
Program Officer
Frascella, Joseph
Project Start
1999-05-01
Project End
2005-04-30
Budget Start
2002-05-01
Budget End
2005-04-30
Support Year
4
Fiscal Year
2002
Total Cost
$294,813
Indirect Cost
Name
Duke University
Department
Psychiatry
Type
Schools of Medicine
DUNS #
071723621
City
Durham
State
NC
Country
United States
Zip Code
27705
Mathew, Roy J; Wilson, William H; Davis, Robin (2003) Postural syncope after marijuana: a transcranial Doppler study of the hemodynamics. Pharmacol Biochem Behav 75:309-18
Mathew, Roy J; Wilson, William H; Turkington, Timothy G et al. (2002) Time course of tetrahydrocannabinol-induced changes in regional cerebral blood flow measured with positron emission tomography. Psychiatry Res 116:173-85