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View Diary: Your War on Drugs: 59 Police car chase, 137 bullets, 2 unarmed people dead. (134 comments)

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  •  Slightly OT (18+ / 0-)

    The propaganda war on marijuana got a boost last year in a study that found that adolescent use might interfere with neurological development and impair cognitive functioning. Well, it turns out the analyses failed to account for socioeconomic effects.

    Does cannabis use have substantial and permanent effects on neuropsychological functioning? Renewed and intense attention to the issue has followed recent research on the Dunedin cohort, which found a positive association between, on the one hand, adolescent-onset cannabis use and dependence and, on the other hand, a decline in IQ from childhood to adulthood [Meier et al. (2012) Proc Natl Acad Sci USA 109(40):E2657–E2664]. The association is given a causal interpretation by the authors, but existing research suggests an alternative confounding model based on time-varying effects of socioeconomic status on IQ. A simulation of the confounding model reproduces the reported associations from the Dunedin cohort, suggesting that the causal effects estimated in Meier et al. are likely to be overestimates, and that the true effect could be zero. Further analyses of the Dunedin cohort are proposed to distinguish between the competing interpretations. Although it would be too strong to say that the results have been discredited, the methodology is flawed and the causal inference drawn from the results premature.

    Be radical in your compassion.

    by DWG on Sat Mar 16, 2013 at 06:27:24 AM PDT

    •  Especially since IQ (12+ / 0-)

      tests are so culturally biased they are useless on most of the 47%.

      There is a long history of creative stimulation attributed to cannabis consumption by some of the greatest minds in history. Any study that makes weed something smart people stay away from is suspect in my eyes because of that.

      "Til you're so fucking crazy you can't follow their rules" John Lennon - Working Class Hero

      by Horace Boothroyd III on Sat Mar 16, 2013 at 06:52:54 AM PDT

      [ Parent ]

      •  True (5+ / 0-)

        The only thing I would add is that the measures were not standard IQ tests but rather tests of attention, memory, and executive (frontal lobe) function.

        The Dunedin data found no evidence of any relationship between adult cannabis consumption and cognitive function, but identified adolescent use as a risk factor for lower adult cognitive function. The authors offered up a critical period hypothesis to account for the effects. It is a bit like exposure to mercury or lead during neonatal development has profound effects on neurological function in later life. The problem with failing to adjust for socioeconomic status is that many factors known to impair neurological development during the critical period are associated with SES, including nutrition, toxic exposures, stress, and addictive substance abuse.

        Be radical in your compassion.

        by DWG on Sat Mar 16, 2013 at 07:26:33 AM PDT

        [ Parent ]

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