一項(xiàng)研究報(bào)告說,，近期一項(xiàng)研究所報(bào)告的在青春期開始使用大麻與智商下降之間的正關(guān)聯(lián)有可能用社會(huì)經(jīng)濟(jì)地位對(duì)智商造成的混雜的影響加以解釋,。Ole Rogeberg使用一個(gè)模擬模型評(píng)估了社會(huì)經(jīng)濟(jì)地位對(duì)智商的潛在影響，結(jié)果發(fā)現(xiàn)這種混雜因素足以重現(xiàn)智商變化和接觸大麻之間的聯(lián)系,，而該聯(lián)系是由此前新西蘭達(dá)尼?。―unedin）的一個(gè)大規(guī)模群組研究所報(bào)告的。此前發(fā)表的基于同一個(gè)達(dá)尼丁群組的論文指出,，早期開始使用大麻的情況在具有某些風(fēng)險(xiǎn)因素的人群中更常見,，這些風(fēng)險(xiǎn)因素與社會(huì)經(jīng)濟(jì)地位低有相關(guān)性。此外,，此前的研究提示有類似的智商但是社會(huì)經(jīng)濟(jì)地位不同的兒童自選或者被選入了對(duì)認(rèn)知有不同要求的環(huán)境,，而這反過來又導(dǎo)致了他們智商的分化。這位作者提出,，得出接觸大麻和智商下降之間的因果推論可能為時(shí)尚早,，而且對(duì)達(dá)尼丁群組的進(jìn)一步分析可能有助于區(qū)分有競(jìng)爭(zhēng)性的解釋,。這位作者說，根據(jù)智商變化是否由于大麻造成的永久性神經(jīng)毒性損傷,，或者智商變化是否由于不同的認(rèn)知環(huán)境造成的其他非永久性效應(yīng),，其所帶來的政策意義可能不同。(生物谷Bioon.com)
doi: 10.1073/pnas.1215678110
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Correlations between cannabis use and IQ change in the Dunedin cohort are consistent with confounding from socioeconomic status
Ole Rogeberg1
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.
