Marijuana: Opponents Factual Brief

Marijuana: Opponent's Factual Brief

OPPONENT'S BRIEF

Factual Proposition: Consuming marijuana is detrimental to one's health.

Definition of key terms:

1. Consumption= Smoking or eating marijuana. 2. Marijuana= Psychoactive mind altering substance, also known as cannabis. 3. Detrimental= Serious harm.

Primary Inference:

Smoking or eating marijuana is likely to create serious health problems for most individual users or society.

Overview:

Since the 1920's supporters of marijuana prohibition have exaggerated the drugs dangers. Many of the “reefer madness” tales that were used to bring support for early anti- marijuana laws , continue to appear in reports today.

The most important studies of recent times took place in the 1970's in Greece,

Costa Rica and Jamaica. These tests reported on the effects of marijuana on its users in there natural environment. The reports covered marijuana's effect on the brain, immune and reproductive systems. (1) These studies didn't answer all the questions about the effects of marijuana on the user, but supported the idea that marijuana for the majority of its users was not detrimental to the health of the users brain, immune or reproductive system. In looking at all the reports that are published there are perhaps, random studies which may indicate greater toxicity of the drug. But in all of these cases, the research was flawed or inaccurate since the findings cannot be duplicated by other scientists.

Contention I: Marijuana does not damage brain cells.

A. Claim: Use of marijuana does not cause memory loss.

1. Grounds: In a recent study rhesus monkeys were exposed to the equivalent of 4-5 joints per day for an entire year without any alteration of hippocampal architecture.(2) Slikker, W. et al,” Behavioral, Neurochemical, and

Neurohistological Effects of chronic Marijuana Smoke Exposure in the Nonhuman

Primate,”pp219-74 in l. Murphy and A. Bartke (eds), Marijuana Neurobiology and

Neurophysiology, Boca Raton: CRC press(1992)

2. Warrant: Alteration in hippocampal structure results in memory loss.

3. Backing: A study reports “ Any alteration of the hippo campus, a cortical brain region, results in negative consequences for learning and memory in humans.(3) Heath, B.C. et al, “Cannabis Sativa: Effects on Brain Function and Ultra structure in Rhesus Monkeys, “Biological Psychiatry 15:657 (1980).

B. Claim: Use of marijuana does not cause cognitive impairment.

1. Grounds: In a study it is reported "marijuana intoxication does not impair brain related cognitive functions"(4)

Weckowicz, T.E. et al, "Effect of Marijuana on Divergent and convergent Production Cognitive Tests," Journal of Abnormal Psychology 84:

386-98(1975)

2. Warrant: Studies have shown that marijuana does not effect brain related cognitive functions.

3. Backing: Researchers have proved scientifically that marijuana does not impair cognitive brain functioning include(5)Hooker, W.D. and Jones, R.T., “

Increased Susceptibility to Memory Intrusions and the Stroop Interference Effect