> environmental related more than anything. It is likely both... that's usually what happens. This study also stopped tracking the twins at age 20, which is f

> environmental related more than anything. It is likely both... that's usually what happens. This study also stopped tracking the twins at age 20, which is far younger than most other studies. Although our study evaluated a subset of subjects who had been daily users over the course of 6 mo to a year, all participants were still young adults at their last assessment. Perhaps regular use over a more prolonged period would result in greater differentiation across groups. This is a possible explanation for the discrepancy of our findings from those of Meier et al. (23), whose subjects were aged 38 y at their last assessment. We additionally were not able to differentiate current heavy users from former heavy users, and thus our results cannot disentangle the acute from nonacute effects of marijuana use on intellectual functioning. To me this makes the conclusions pretty useless. They are still adolescents, not adults. They haven't used cannabis over a long period of time, which seems to be the real determining factor. > cannabis leads to a school dropouts Yeah, well that's my personal experience. I watched it happen in my own life. If that's not good enough for your "modern, scientific, society", why bother making this topic? I thought you wanted personal experiences.