Margaret Haney, a professor of clinical neuroscience and the co-director of the Substance Use Research Center at Columbia University, does some cannabis myth-busting. Among her various data points:

Marijuana can produce dependence but at a lower rate than other drugs of abuse. Epidemiological data suggest that about 42 percent of the U.S. population has tried marijuana and about 9 percent met criteria for dependence on marijuana at some point in their lifetime, while 15 percent met criteria for dependence on alcohol and 32 percent for tobacco.

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