Effects of marijuana

Vachon L, Fitzerald MX, Solliday NH, Gould IA, Gaensler EA. Singledose effect of marijuana smoke bronchial dynamics and respiratory-center sensitivity in normal subjects. N Engl J Med 1973 288 985-989. 

Relatively few human imaging studies have evaluated the effects of marijuana or THC on metabolism or blood flow. Acute intravenous THC in both normal controls and habitual marijuana users led to increased an increased regional cerebral metabolic rate (CMR) in the cerebellum. This increase is positively correlated both with concentrations of THC in the plasma and with the intensity of the subjective sense of intoxication [5]. In a 1997 PET/[lsO]water study with 32 abusers [6], THC dose-depend-ently increased cerebral blood flow (CBF) in the frontal regions, insula... 

The involvement of the cerebellum in the psychoactive effects of marijuana and in changes in rCMR is consistent with the view that THC interacts with the high concentration of CB1 receptors in this brain area. Decreases in the cerebellar rCMR in habitual marijuana users may reflect the effects of chronic exposure to the drug. Functions known to be associated with the cerebellum, such as motor coordination, proprioception, and learning, are adversely affected both during acute marijuana intoxication and in habitual users. 

Bloch E (1983). Effects of marijuana and cannabinoids on reproduction, endocrine function, development and chromosomes. In KO Fehr and H Kalant (eds), Cannabis and Health Hazards. Addiction Research Foundation, Toronto. 

Dunn M and Davies R (1974). The perceived effect of marijuana on spinal cord injured males. Paraplegia, 12, 175. 

Kolansky H and Moore WT (1972). Toxic effects of marijuana use. Journal of the American... 

EFFECTS OF MARIJUANA COMPONENTS ON THE IMMUNE RESPONSE AND SUSCEPTIBILITY TO INFECTION... 

Chait LD. (1990). Subjective and behavioral effects of marijuana the morning after smoking. Psychopharmacology (Berlin). 100(3) 328-33. 

Feinberg I, Jones R, Walker J, Cavness C, Floyd T. (1976). Effects of marijuana extract and tetrahydrocannabinol on electroencephalographic sleep patterns, din Pharmacoi Ther. 19(6) 782-94. 

Harclerode J. (1984). Endocrine effects of marijuana in the male preclinical studies. NIDA Res Monogr. 44 46-64. 

Wilson WH, Ellinwood EH, Mathew RJ, Johnson K. (1994). Effects of marijuana on performance of a computerized cognitive-neuromotor test battery. Psychiatry Res. 51(2) 115-25. 

Another problem for the makers of naltrexone was recently uncovered by researchers testing the drug on marijuana smokers. To the researchers surprise, people who were given naltrexone and then smoked marijuana reported that they felt greater psychotropic effects from the marijuana than if they had simply smoked the marijuana alone. In other words, while naltrexone blocks the psychotropic effects of alcohol, heroin and opium, it appears to increase the effects of marijuana. 

The subjective effects of marijuana vary from individual to individual as a function of dose, route of administration, the experience and expectation of the subjects, and individual vulnerability to certain psychoactive substances. Motor coordination also may decrease, especially in situations requiring highly complex motor skills, such as flying an airplane and driving an automobile. 

A. Amaral. Effect of marijuana in the glucose-tolerance test. Ann N Y Acad Sci 1971 191 54-60. CS037... 

Jones, R. T. Cardiovascular system effects of marijuana. J Clin Pharmacol 2002 42(11 Suppl) 58S-63S. 

CS438 Block, R. I., W. J. Erwin, R. Farinpour, and K. Braverman. Sedative, stimulant, and other subjective effects of marijuana relationships to smoking techniques. Pharmacol Biochem Behav 1998 59(2) 405-412. 

The Schedule I designation of marijuana has been disputed over the past 15 or more years. Some physicians would like to see it as a Schedule II drug so that it could be used therapeutically in the treatment of the nausea, vomiting and anxiety caused by cancer chemotherapy and as an antiglaucoma agent (lowers intraocular pressure). It should be noted that the neuroleptic prochlorperazine is an effective antinausea drug which can be used without producing the psychoactive effects of marijuana. 

A relatively large number of studies have investigated the effects of marijuana on focused attention, including reaction time tests and the DSST. Marijuana (1.8 and 3.6% THC) was shown to slow responding on a simple, visual reaction time task 242 however, others have not found marijuana to impair simple reaction time performance.11,40,236 Similarly, some studies have shown that marijuana impairs complex or choice reaction time tasks,11,233 whereas others have shown no effect.234 O Leary et al.243 found no effect of a 20-mg marijuana cigarette on reaction time in a dichotic listening task. 

Marijuana also impairs sustained attention. In a 30-min vigilance task, hashish users exhibited more false alarms than non-using control subjects 257 This finding is consistent with the observation that the impairing effects of marijuana on sustained attention are most evident in tests that last 30 to 60 min tests with durations of 10 min are not adversely affected by marijuana.11... 

Yesavage, J.A. et al., Carry-over effects of marijuana intoxication on aircraft pilot performance a preliminary report, Am. 3. Psychiatry, 142, 1325, 1985. 

Heishman, S.J. et al., Acute and residual effects of marijuana profiles of plasma THC levels, physiological, subjective, and performance measures, Pharmacol. Biochem. Behav., 37, 561, 1990. 

Bolla, K.I. et al., Dose-related neurocognitive effects of marijuana use, Neurology, 59, 1337, 2002. 

Kelly, T.H. et al., Multidimensional behavioral effects of marijuana, Prog. Neuropsychopharmacol. Biol. Psychiatry, 14, 885, 1990. 

Block, R.I., Farinpour, R., and Braverman, K., Acute effects of marijuana on cognition relationships to chronic effects and smoking techniques, Pharmacol. Biochem. Behav., 43, 907, 1992. 

Liguori, A., Gatto, C.P., and Robinson, J.H., Effects of marijuana on equilibrium, psychomotor performance, and simulated driving, Behav. Pharmacol., 9, 599, 1998. 

Automobile and truck simulators have also been used in randomized studies to demonstrate the impairing effects of various doses of alcohol.78-80 Similar studies have been conducted using flight simulators.81-85 In addition, both types of simulators have been used to assess the effects of marijuana, nicotine, and other sedative medications.86-88 Simulations have also been used to examine other environmental perturbations, including sleep deprivation and elevated carbon dioxide levels.89,90... 

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