
Long-term effects of Cannabis - akg
http://www.pnas.org/content/109/40/E2657/1
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sp332
Full text PDF <http://ernstchan.com.nyud.net/fefe/src/1346163651220.pdf>

Actual title is "Persistent cannabis users show neuropsychological decline
from childhood to midlife".

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revelation
Realistically, whats the chance you can get a statistically significant result
in the very hostile environment that surrounds cannabis use from such a very
broad study?

They couldn't closely control the purity, variety or frequency of cannabis
use. They obviously can't control for social stigma.

I guess this is just my general displeasure at articles fishing for
correlations in a sea of bad data, longing for that resolving barrier of
"statistical significance".

~~~
gillett
Normally I would agree with you, but the controls you are calling for are
unrealistic. While I'm no expert in the field, this is clearly not the first
study to suggest long-term cognitive decline in adolescent-onset users, and
any evidence that can support previous findings, albeit very small, is
important to consider.

I think the authors are correct in stating that there is a popular and naive
belief among adolescents that cannabis is safe - especially in moderation -
and the evidence to date does nothing but refute that. Hell, in this study
they found a statistically significant IQ drop (over the course of 20 years)
for adolescent-onset users that only smoked 14 days out of the year on average
(the median, to be precise). Even if they do put forth incomplete or
questionable conclusions, teens should be exposed to more of these findings
and be allowed to think for themselves. They certainly should not have to
endure the inane public service announcements that merely reinforce the belief
that marijuana is not actually "that bad."

~~~
andreasvc
There is an even more popular and naive belief that drinking alcohol is safe.
With the current social conventions and legislation the consumption of this
solvent is pervasive and deemed acceptable, while other drugs which are
objectively less harmful are criminalized ferociously. It has to be said that
all this is a rather arbitrary state of affairs.

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xk_id
This definitely echoes my own observations. Due to various circumstances, in
my life I have so far been thoroughly exposed to numerous, unconnected groups
of drug users – all of which were smoking weed more or less regularly, and
almost all of which were losers. I am very happy to find out about this study,
and I hope it receives an adequate exposure.

~~~
psweber
Sounds like you've never met a graphic designer.

~~~
Chaotic
Or a programmer.

~~~
bsenftner
or a successful entrepreneur

~~~
paulhauggis
But you don't know how much more successful they could be without smoking pot
regularly.

~~~
xk_id
thanks, I didn't want to say it myself :)

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thracky
Let's see who funded the study: (* added for emphasis) "This research received
support from UK Medical Research Council Grants G0100527 and MR/K00381X/1, US
National Institute on Aging Grant AG032282, US National Institute of Mental
Health Grant MH077874, and _US National Institute on Drug Abuse_ __ __ __ __*
Grant P30 DA023026. Additional support was provided by the Jacobs Foundation."

I agree adolescents probably shouldn't partake, but for adults, there's far
worse things.

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joekrill
The content is behind a pay wall

~~~
Fuzzwah
Welcome to the wonderful world of publicly funded science publication!

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xk_id
can anyone name one figure who had an important contribution to mankind, and
smoked weed?

~~~
yeabuddy
Carl Sagan

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xk_id
Thanks, I didn't know

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Chaotic
So wait, let me get this straight. Using cannabis irregularly means that I
will lose about one IQ point by the time I hit middle age? If there was ever a
reason to smoke up!

~~~
njs12345
6 IQ points is a bigger deal, but for any of the other groups, the effects are
certainly fairly minor..

