Advocates of increased use of pot through legalization often mock the 1930's film, "Reefer Madness." The idea seems to be that only Puritanical, moralistic, anti-science zealots could think the pot might adversely affect brain development.
Today comes news from that citadel of Puritanical, moralistic, anti-science zealotry, Northwestern University:
Casual marijuana use may come with some not-so-casual side effects.
For the first time, researchers at Northwestern University have analyzed the relationship between casual use of marijuana and brain changes - and found that young adults who used cannabis just once or twice a week showed significant abnormalities in two important brain structures.
The study's findings, to be published Wednesday in the Journal of Neuroscience, are similar to those of past research linking chronic, long-term marijuana use with mental illness and changes in brain development.
Ooooooops.
The study does not demonstrate that marijuana adversely affects brain development. It shows a correlation between changes in certain brain structures and marijuana use. It does not purport to demonstrate causation nor does it purport to show actual negative health effects by examining the impact of the structural changes on behavior or anything else.
Scientists should certainly continue to conduct research on the health effects of marijuana use. People should be informed of the risk of any behavior they engage in, and research on the harms caused by tobacco smoking certainly changed societal views and behaviors. I can't imagine that the quality and quantity of marijuana research is bolstered by prohibition, however. Probably difficult to do a longitudinal study of the impact of ongoing criminal behavior.