Marijuana, Cannabis Sativa, has been used for centuries for its medicinal and euphoric properties, and its fibers, to produce hemp fabrics and paper. In medicine, between 1850 and 1942, it was prescribed in the United States Pharmacopeia as a remedy for a variety of ailments including gout, tetanus, depression, and cramps (Farthing 1992). Today it is used to reduce intraocular pressure due to glaucoma, as an antiemetic to relieve nausea associated with chemotherapy, and as an appetite stimulant in AIDS patients. For recreational purposes, it is the most used illicit drug, especially among adolescents. The main psychoactive component of marijuana is 9-tetrahydrocannabinol (THC). Other important cannabinoids include cannabidiol, cannabinol, and 9-tetrahydrocannabinic acid. Together, these compounds contribute to various behavioral and cognitive changes, which may differ slightly based on the route of preparation and administration (Farthing 1992 is found in the sticky resin of the cannabis plant, with the highest concentration in the flowering tips (buds) of the female) . Marijuana is a preparation of leaves, stems and buds, while hashish is a concentration of the resin. Smoking and oral ingestion are the most common modes of administration and may produce slightly distinct effects due to different digestive filtering methods. tract and lungs. The subjective experience of marijuana may include a prolonged passage of time, impaired awareness of self and environment, and occasional paranoia or increased anxiety. At sufficiently high doses one may even experience hallucinations (Farthing 1992). A wide range of acute cognitive effects, including difficulty with motor skills, have been reported during intoxication. (As cited by Chan et al. 1998) Drew WG et al. Effects of hippocampal brain damage on recent auditory and visual memory: comparison with marijuana intoxicated subjects. Biological Psychiatry 15 (6): 1980. Farthing, G. W. The psychology of consciousness. Prentice Hall (1992). Gazzaniga, MS, Ivry RB, & Mangun, GR Cognitive neuroscience: the biology of the mind. W. W. Norton & Company (1998). Herkenhaum, M. et al. Localization of cannabinoid receptors in the brain. Proceedings of the National Academy of Sciences USA 87: 1932-1936 (1990). Kandel, E. R. & Schwartz, J. L. Principles of Neuroscience. Elsevier (1985). (As cited by Amen & Waugh 1998) Murray, Effects of JB Marijuana on human cognitive functions, psychomotor functions, and personality. The journal of general psychology 113(1): 23-55 (1985).