Discussion on Marijuana and its Long-term Effects: with Studies

So far this has been a two-part discourse. The first part was my elucidating of a study on marijuana usage, and the second part I’ll post in a “reply-post” or two. It contains his reply in full, and in order, with my responses interspersed.

Hey Ben,

A study called “The Toxicity of Cannabis”, available here (click “Get PDF” at the bottom), published in a journal of chemistry and biodiversity, concludes (page 20 of the pdf, with my bolding): The recently observed increase in cannabis use, particularly among younger people, poses potential harm to individuals and society at large, and must clearly be attended to by society. The extent of the risks associated with cannabis use depend on several factors. According to the above review, young age among users, regular and heavy use, and the smoking of cannabis cigarettes are factors most likely to increase the negative effects of cannabis use. The greatest concerns should be associated with minimizing cannabis use by young adolescents. Potentially negative long-term effects of cannabis use, including dependency, induction of psychosis, effects on cognition and academic achievement are more severe in young people than in adults.Some long-term effects are summarized this way in the abstract: Effects on cognitive abilities seem to be reversible after abstinence, except possibly in very heavy users.A very relevant paragraph on page 14 of the pdf reads: Among these studies is the one by Pope et al. who compared three groups of individuals aged 30 to 55 years with regard to their cognitive abilities following cessation of cannabis use: 63 current heavy users of cannabis, 45 former heavy users, and 72 nonusers [116]. Some cognitive deficits were detectable at least seven days after discontinuation of heavy cannabis use. By day 28, however, there were virtually no significant differences among the groups on any of the test results, suggesting that cannabis effects on cognition in heavy users appear to be reversible and related to recent cannabis exposure. However, another investigation suggests that very heavy use of cannabis may be associated with irreversible decline in cognitive performance [117].Footnotes:[116] H. G. Pope, A. J. Gruber, D. Yurgelun-Todd, Curr. Psychiat. Rep. 2001, 3, 507.
[117] K. I. Bolla, K. Brown, D. Eldreth, K. Tate, J. L. Cadet, Neurology 2002, 59, 1337.Cognitive deficits are apparent at least after seven days! That’s significant – and that’s not just for heavy users. The same study states (see below) that long-term effects in regular/moderate users can be reversed if subjects stop using the drug a week prior to testing – which makes sense, because if they stop using it there’s no reason to expect they won’t recover. Nevertheless, that shows that moderate users AND heavy users BOTH test poorly in tests of cognitive function, unless they quit the drug; and it takes heavy users significantly longer to recover (up to 28 days). Both durations of impairment are significant to any average person in society, unless he stays at home for a week (or 28 days) and doesn’t use the drug during that time.

Text of that section (page 14 of the pdf, with my bolding): Participants were divided according to the number of joints smoked per week into light users (mean: 11 joints), medium users (mean: 42 joints), and heavy users (mean: 94 joints). Very heavy users performed significantly worse on 5 of the 35 tests compared to light users even after 28 days of controlled abstinence. Memory, executive functioning, psychomotor speed, and manual dexterity were affected. In a more recent study, no differences in the performance of moderate regular cannabis users, who were abstinent from the drug for one week, and non-users in tasks on working memory and selective attention were observed [118].Footnote: [118] G. Jager, R. S. Kahn, W. Van Den Brink, J. M. Van Ree, N. F. Ramsey, Psychopharmacology 2006, 185, 358. I’d love to see you refute this information.

God bless!
-Dan Marcum

This is the second part of our dialog. His replies are reported in full and in order, with my responses interspersed:

Hey Ben,

"From the same study:

“Adverse effects of medical cannabis use are within the range of effects tolerated for other medications [11] [67] . Long-term medical use of cannabis for more than 15 years is reportedly well-tolerated without significant physical or cognitive impairment [68] . Side effects observed in acute clinical studies diminish considerably with longer medicinal use [7].”

Medical use isn’t at issue. No one is opposed to that. We’re discussing recreational use. Imagine trying to legalize steroids as a performance enhancer, on the basis that it can be used in medical treatments without issue. That’s what you seem to be trying here.

“The medical benefits of cannabis for some indications and the problems caused by continued prohibition of its medical use, recently prompted several medical journals to endorse reconsideration and reclassification of medical cannabis. In 2005, the editors of MedGenMed and the Journal of the American Medical Association pleaded for a reclassification of cannabis in the USA, so that its medical use would be allowed under federal law [176] [177].”

First, I thought that medical use of marijuana was already permitted in most localities, and perhaps it actually is, even though this study seems to imply otherwise. But even if medical usage isn’t currently permitted, there is a difference between legalizing marijuana for medical study and usage on the one hand, and legalizing marijuana for recreational usage on the other. And even if they couldn’t legalize the one without legalizing the other, it does not follow that it should be legalized for the sake of potential medical benefits; rather, it should be kept illegal, for the known problems it causes in the mind, and other products should be studied and used for medical treatments, if it isn’t possible to study marijuana unless it is first legalized wholesale. Because the real problem with marijuana is simply that, in ordinary usage, it significantly separates people from their reason and judgment, not only in the short-term (which would be grounds enough to keep it illegal), but long-term as well (a week or more, depending on how heavy you hit it).

“The Editors of the Journal of the Canadian Medical Association not only advocated the legal medical use of cannabis but also the general decriminalization of cannabis for personal use. They argued that the social and legal consequences of being arrested for cannabis possession and obtaining a criminal record far outweigh the minimal health effects of moderate cannabis use [178] .”

That is an argument for a particular policy; it is not proof against my argument, which is this: marijuana does significantly affect people’s reason/judgment in ways that risk a negative impact to society. Society has an interest in preventing its own harm. Therefore, society should outlaw recreational marijuana use.

The fact that the authors of that study disagree with this political argument is not proof against it. The scientifically demonstrated reality is that regular marijuana use does have a negative impact on people’s reason/judgment, not only in the short-term, but in a way that affects them in the outside world too.

“This review of the toxicology of cannabis and the effects of currently used control strategies suggests that cannabis is a drug of moderate toxicity, particularly when used by adults. Because it may create undesirable effects on personal development and health, cannabis use by adolescents should be discouraged effectively. The medical use of cannabis appears to offer some persons benefits for a wide range of indications.”

This only supports marijuana prohibition. You are right that moderate toxicity wouldn’t be enough by itself; but the effects of this substance – and note the admission about the effects on health – are just further grounds for prohibiting it among everyone, not just adolescents. And as for its medical potential, that is not at issue, because that can be permitted without legalizing its recreational use.

Cont’d next.

Cont’d from last.

I am a little concerned with how you presented the bulk of your information. You presented me with a work citing almost two hundred sources that concludes cannibis use AT WORST is comperable to cigarettes and may have A WIDE RANGE OF BENEFITS including but not limited to: reduced pain for numerous neurological diseases, including MS and use as a potential cancer reducer and inhibitor. All cited within the paper.

First, I am not at all afraid of this information; if I was, I wouldn’t have linked you to it and cited page numbers for your review – I just would have quoted it out of context and kept you in the dark as to the rest of the research. The numerous sources it cites about the medical benefits are completely out of left-field when the position I am advocating is that marijuana be kept illegal except for medicinal use – just like steroids already is.

Second, your statement that the “worst” effects of cannabis are comparable to those of cigarettes, is a blind way of reading the cognitive data, which speaks of verifiably lower scores on cognitive reasoning tests among regular users of moderate amounts of marijuana. I’m sorry, cigarettes won’t do that to you. Perhaps the physical effects are not worse than cigarettes, but the physical effects are not the real problem here.

Regarding the Pope paper (the one study that you relied upon entirely out of 187 studies cited) the crux of your argument lies in the following sentence:

“Potentially dependency, induction of psychosis, effects on cognition and academic achievement are more severe in young people than in adults.”

Wrong. The crux of my argument rests in the study about moderate users’ cognitive problems. Unless users quit the drug a week prior to testing, they test poorly on cognition. That demonstrates that even moderate marijuana use hurts your mind in verifiable ways, and moderate use requires “recovery time” in order to restore your usual intellectual powers.

The problems it has on young people, which are even more pronounced, are just further evidence that it should be prohibited.

The study is also inconclusive and states: Few differences were found between late-onset users and controls on the test battery. After adjustment for verbal IQ, virtually all differences between early onset users and controls on test measures ceased to be significant.

The authors suggested three alternative explanations for poorer cognitive performance in early-onset cannabis users:

  1. innate differences between groups in cognitive ability, antedating
    first cannabis use;
  2. an actual neurotoxic effect of cannabis on the developing brain; or
  3. poorer learning of conventional cognitive skills by young cannabis users who have eschewed academics and diverged from the mainstream culture.

So adolescents might not suffer greater damage than adults. Okay, but this only supports my point, because an age-based test of damage intensity PRESUPPOSES that all users suffered a certain amount of cognitive damage! That is where my beef lies. These tests all show that cognitive function is verifiably impaired, both among moderate users and, especially, among heavy users, where it is sometimes, perhaps, irreversible. Therefore, marijuana use should continue to be prohibited.

This single paper out of the 187 cited, doesn’t reach the conclusion you infer and you MUST be careful not to misrepresent information. You cited me the strongest sentence of the abstract that supported your position and OMITTED the conclusion of this massive accumulation of data that undermined your position.

The single paper supports the conclusion I inferred and I did not misrepresent it. None of the other research undermines my position, but rather, much of it further obviates the detrimental effects of recreational marijuana use on society, which is grounds for keeping it illegal. The abstract supported my position, and the conclusion did not contradict that; some statements in the conclusion back me up even further, even though the authors have a political disagreement about the best way to handle the problems posed to society by marijuana usage. But they admit, in the conclusion, that it poses problems: “The recently observed increase in cannabis use, particularly among younger people, poses potential harm to individuals and society at large, and must clearly be attended to by society.”

If all you’ve got in favor of legalization, is that there may be some helpful medical benefits, and the old “everybody’s doing it anyway” argument, I submit that reason will prevail in the public eye, and marijuana will remain illegal. Anyway, we can hope that discussions like this will promote the public discourse on the subject.

It’s been fun for me, and I’d like to continue if you have further thoughts. So email me back and we’ll talk some more.

God bless!
-Dan Marcum

Their cognitive skill might go down for up to a month after smoking weed but its not like they have to stay home or that they can’t function during that month, lol. Unless people are going around killing people if they can’t answer somewhat complex math problems and puzzles I don’t think it is really an issue. Either way it seems like a non issue because the study suggests that even long term users can pretty much be back to full mental capacity within a month of stopping. That is far from the truth with alcohol and other drugs as far as I know.

And this has what to do with apologetics?

First, that’s a very low standard of conduct to demand; as if all laws are reduced to “Are you running around killing people?”

Second, you have no evidence that these tests were just math problems and puzzles; you ought to check out the study before criticizing its methodology.

Giving reasons for opposing marijuana usage. Apologetics is not just slinging Bible-quotes, you know. Politics is one place where your faith should inform your positions, and good solid data backs up the Catholic position on marijuana use.

Ah, ok. Carry on…

Why did God create it.

You’ll have to ask Him; perhaps it was to teach us, with another example, that not all plants are good for you if you ingest them, and to give us an opportunity to do what is right, in spite of the presence of an alternative.

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