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Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
21–30 of 95 posts
Re: Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
#22My issue with this study is they based it around IQ points. I feel like IQ is a very bad measure of cognitive ability outside of determining if someone is competent of not. And the fact that it only went down by a mean of 5.5, I feel like that small of a decline could be attributed to someone just having a bad day or being a little groggy when they took the IQ test.
Had the measured brain waves or brain activity it would be one thing, but I feel like an IQ test is just not satisfactory for a study like this.
Re: Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
#23Look at the sample sizes and the demographics ( https://imgur.com/a/LG5vVMF ) of the groups the study ( https://moffittcaspi.trinity.duke.edu/sites/moffittcaspi.tri... ) compares. Also look at the publication bias of the first author ( https://scholar.google.com/citations?view_op=list_works&hl=e... ).
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Re: Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
#24Here's the actual paper. Long-term Cannabis Users Show Lower Cognitive Reserves and Smaller Hippocampal Volume in Midlife: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9426660/
From the abstract:
> We tested the hypotheses that long-term cannabis use is associated with cognitive deficits and smaller hippocampal volume in midlife, which is important because midlife cognitive deficits and smaller hippocampal volume are risk factors for dementia.
> Participants are members of a representative cohort of 1,037 individuals born in Dunedin, New Zealand in 1972–73 and followed to age 45 years, with 94% retention. Cannabis use and dependence were assessed at ages 18, 21, 26, 32, 38 and 45 years. IQ was assessed at ages 7, 9, 11, and 45 years. Specific neuropsychological functions and hippocampal volume were assessed at age 45 years.
> Long-term cannabis users showed IQ decline from childhood to midlife (mean=−5.5 IQ points), poorer learning and processing speed relative to their childhood IQ, and informant-reported memory and attention problems. These deficits were specific to long-term cannabis users because they were either not present or smaller among long-term tobacco users, long-term alcohol users, midlife recreational cannabis users, and cannabis quitters. Cognitive deficits among long-term cannabis users could not be explained by persistent tobacco, alcohol, or other illicit drug use; childhood SES; low childhood self-control; or family history of substance dependence. Long-term cannabis users showed smaller hippocampal volume, but smaller hippocampal volume did not statistically mediate cannabis-related cognitive deficits.
Re: Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
#25This is not a primary source of anything related to psychology. This site is article marketing for people in the mental health field. The primary motivation of the author's is to self promotion.
You might say that article is, in many ways, a puff piece.
Re: Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
#26My issue with this study is they based it around IQ points. I feel like IQ is a very bad measure of cognitive ability outside of determining if someone is competent of not. And the fact that it only went down by a mean of 5.5, I feel like that small of a decline could be attributed to someone just having a bad day or being a little groggy when they took the IQ test. Had the measured brain waves or brain activity it w…
5.5 is a massive decline in IQ.
Re: Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
#27I smoked weed constantly in college, and when I stopped, it was like a fog lifted. Its danger was comically exaggerated in the anti-drug propaganda they force fed to kids in the US for so long that a lot of people have a reactionary tendency to assume it's harmless, but they will soon be proven wrong. Still has nothing on America's number 1 hard drug, alcohol, though.
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Re: Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
#28My issue with this study is they based it around IQ points. I feel like IQ is a very bad measure of cognitive ability outside of determining if someone is competent of not. And the fact that it only went down by a mean of 5.5, I feel like that small of a decline could be attributed to someone just having a bad day or being a little groggy when they took the IQ test. Had the measured brain waves or brain activity it w…
Have you got any reason to think IQ is a bad measure of cognitive ability? And what makes you think 5.5 points is small? The average is 100 and a typical standard deviation is about 15; one third of a standard deviation looks pretty big to me.
Re: Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
#29This is pretty important kind of research. Tons of people are using this stuff medically and while it's obviously a better solution for pain management than long-term use of things that can kill you if they're suddenly unavailable, like opiates, we should still be highly aware of mitigating whatever harms could come from the widely used alternatives. It would also be more interesting to see harm in aspects of things…
Lots of people use it recreationally with the belief it’s not bad for you at all. This kind of research will help to show them that’s not the case.
Re: Long-Term Cannabis Use, Cognitive Decline, and the Hippocampus
#30Look at the sample sizes and the demographics ( https://imgur.com/a/LG5vVMF ) of the groups the study ( https://moffittcaspi.trinity.duke.edu/sites/moffittcaspi.tri... ) compares. Also look at the publication bias of the first author ( https://scholar.google.com/citations?view_op=list_works&hl=e... ).
if you mean the very small mean iq difference at baseline, that is hardly a significant concern, here especially in a longitudinal design. As far as publication bias, do you mean expert in his/her field?