Marijuana is the most commonly abused illegal drug in the United States. It is of particular concern that this drug is abused by large numbers of adolescents. Thus, the acute and chronic effects of marijuana and its active ingredients, including THC, are of considerable research interest and clinical significance. A number of investigators demonstrated alterations in brain function via neuropsychological testing in chronic marijuana users. With the recent advent of non-invasive techniques, it has become possible to measure cerebral blood flow (CBF) during cognitive testing in humans. In such activation studies, CBF serves as an index of regional brain function. All four available studies on CBF in chronic marijuana smokers found reduced global flow which reached statistical significance in three. Studies were conducted with the 133 xenon inhalation technique and positron emission tomography. Acute marijuana intoxication was found to increase CBF with more marked changes in the right hemisphere and in the cingulate gyrus. Behavioral studies have indicated a number of neuropsychological abnormalities, including impairment of short-term memory as measured with the digit symbol substitution test. In the proposed study we shall use PET to assess regional CBF changes during recognition and recall activation tasks following THC or placebo infusion in marijuana smokers. We shall also compare resting CBF with neuropsychological test.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA010215-02
Application #
2517986
Study Section
Human Development Research Subcommittee (NIDA)
Project Start
1996-09-25
Project End
1999-08-31
Budget Start
1997-09-01
Budget End
1998-08-31
Support Year
2
Fiscal Year
1997
Total Cost
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