“Long-term marijuana use may fog the brain”

Thursday, March 23, 2006
Radio talk host Michael Medved cited a new medical study which claims “Long-term users of marijuana gradually become worse at learning and remembering things.”

“Long-term users performed worse in tests to measure memory, learning ability and the capacity to recall information. Asked to recall lists of 15 words that they had seen earlier, for example, the long-term users averaged seven, compared with nine recalled by short-term users and 12 by controls.

“Long-term users found it very difficult to learn through new information given verbally,” says Messinis. “It’s not to do with lack of attention but more the encoding process of memory.” Separate tests to probe attention span found that long-term users were able to pick up information immediately, without trouble.”

Study cited

Might this explain the weird reasoning of many leftists? Are they functioning on a lower level than their more conservative opponents? I haven’t given this much thought. Nonetheless, it might explain a lot of things. How many of the Daily Kos kids smoke marijuana on a regular basis? 10%, 20%, 30%---or even higher?


Syl said...


Puhlease. First, very few leftists actually USE marijuana. Second, I think this study is bogus.

I've sworn off 'studies'. Every day there's another one, or two, or three, proving or affirming someone's agenda.

How many studies with opposite results can we take anyway? To hell with the lot of them.

BTW, my short-term memory is shot to hell. Some days it's worse than other days and I can't even remember a phone number between the time I look it up and when my finger reaches the pushbuttons.

But it has nothing to do with marijuana or anyone else's pet bugaboo. It's my thyroid hormone level.

As Crichton reminds us, the brain is a complex system. And manifestations of complex systems cannot be explained by any study focusing on one parameter.

David Thomson said...

No, this is a very reputable study. Does it partly explain today's leftists? Especially those over 50? I think this is something we may have ignored for far too long.

Syl said...

Well, don't libertarians smoke marijuana too?

I think you're looking for too simple answers.

And they're all 'reputable' studies.

David Thomson said...

It does not explain everything. I don't think, for instance, Hillary Clinton smokes pot. She has other problems. Still, a number of hard core leftists do. This study clearly shows that mariuana smoking clouds one's reasoning abilities.

Eric Blair said...

I know plenty of 'conservatives' that toked up in college. It doesn't seem to have impaired them any.

Of course, they've out grown that, and are not using it now.

JB said...

"Well, don't libertarians smoke marijuana too?"

Yeah, and judging by the moonbats at Reason/Hit-and-Run there may be something to this study.

They should rename that magazine Emotion.

terrye said...


I think this study is about as reputable as the one Berkely did stating that whiny cranky kids grow up to be conservatives.

Morgan said...

Having read it, I'll say that this is a reasonably good study. However, here's the logic behind the conclusion:

People (who told us) that they were marijuana users who had (according to them) abstained from marijuana use for at least 36 hours performed much worse (as a group; for some reason) on a set of standard cognitive tests than did people (who told us) that they were not marijuana users.

The only thing we know was different about the two groups was that one said it uses marijuana, while the other said it does not.

Therefore, marijuana use clouds thinking.

That might be the most reasonable conclusion to draw, but it is not the only possibility.

No study is perfectly definitive - I just wish researchers were able to admit it.

Pastorius said...

What were we talking about again?

Pastorius said...

Couldn't help myself.

Rick Ballard said...

"What were we talking about again?"

I dunno, man, it's way complicated. Hey you got any papers?

Rick Ballard said...

If one considers that a primary claim of dope peddlers around the world is that it "takes the edge off", why is a study confirming the claim any surprise at all? A study showing that marijuana sharpens intellectual focus and mental acuity would be a surprise. This one just supports a major marketing premise.

I don't think that DT's extrapolation is particularly convincing - unless the hypothesis is extended to include a supposition that lefties alternate smoking dope with smoking crack.

terrye said...

I'm hungry.

Speaking of drugs, pot was a lot easier for me to walk away from than tobacco.

Syl said...

And speaking of tobacco...there were studies that said smokers concentrated better at work than non-smokers.

But there would be the corollary--if you are a smoker but haven't had one in 36 hours, your ability to concentrate is lessened.

But this isn't permanent. After a period of time without smoking, your brain goes back to the concentration level it had before you picked up your first cigarette.

Wouldn't surprise me if the same mechanism is involved here. It's the conclusions projected from the study that are in error.

Just like all those other studies we hear about day after day after day...somebody with an agenda puts a spin on it and leaps farther than the study merits.

Rick Ballard said...

JAMA Abstract of another recent study with the same results.

Seneca the Younger said...

You know, I was going to comment on this, but I forgot what I was going to say.

Seneca the Younger said...

Okay, everyone else made the joke too, but I don't care. It was a good line and I love it like it was my own.

Morgan said...

Am I the only person on the web who never toked?

loner said...

As a not infrequent user of the herb in question for a great many years prior to 1985, I can report that I quit at the beginning of that year because more and more often while under the influence I was suffering from a general paranoia regarding such things as being able to ascend and descend stairs.

Within a year of quitting I suffered through the first of what I came to understand were severe panic attacks. It took some years, but eventually my panic attacks were constant whenever I was outside my residence and not infrequently constant while I was awake.

When I finally sought help I decided to try biofeedback because I'd so far managed to confine my addictions to caffeine and nicotine and I didn't want to be dependent on a drug unless it was absolutely necessary. I began by giving up the caffeine (easily the most difficult of all the drugs to stop using) and nicotine, doing an hour of therapy once a week, doing relaxation exercises at least twice a day and looking for ways improve my quality of life. With time and work the panic attacks stopped.

What also happened is that my mind, freed from constantly concentrating on my anxiety, tended (and tends) to shutdown if I'm not paying attention. I've never been able to regain my focus. This is possibly because I've always feared that doing so would bring back the panic attacks and that would be intolerable.

That's my story. For a long time I got a lot of enjoyment from smoking the herb and didn't feel that either my concentration or my memory were being adversely effected. In fact, I think the computer has had a much more pronounced effect on my memory (or need thereof) than any chemical that has gone into my body. When the use of the herb ceased to produce a positive buzz I stopped using it.

As to ideology, for low these many years it seems to me that in the United States your ideological-spectrum label has mainly depended on whether or not you think whoever is president is doing a good job. I never think the president is doing a good job. I do think he is doing a difficult job, but I don't much credit that as he begged to do it. When I was using the herb I was more "conservative" than I am now except, of course, when it came to drug policy. There I've always been, and continue to be, a libertarian.

MaxedOutMama said...

From my personal observations of tokers, I think they tend to become mentally passive but very suggestible when they are not toking. I also think it stops a person's personality from maturing. The youngest 50 year-olds I have ever known are marijuana using college professors.

I'd be interested in a study of long-term marijuana users that looked at the whether they were particularly vulnerable to fixed thoughts stimulated by outside suggestion.

On the other hand, there is at least a decent possibility that long term marijuana use is somehow a compensation. Is it possible that the majority of people who use marijuana consistently for long periods of time don't like to be mentally stimulated, which would probably accentuate the normal effects of aging?

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