Cannabis is widely used, psychoactive, and addictive. Given the choice, people in several US states and the District of Columbia have voted to legalize it. In the nation’s capital, it is now legal to possess as many as 3 Cannabis sativa plants. Meanwhile, it remains illegal to have cannabis on federal land, which is problematic in a mosaic of federal and local jurisdictions. Further, a federal worker stands to be fired if discovered to be using cannabis. In the cannabis debate, does the science of consequences and addictive liability matter? Studies of humans and animals strongly indicate that cannabis changes the structure and function of the brain,1 and the propensity to cannabis addiction is heritable,2 which means that some are more vulnerable. On the other hand, it has been advocated that cannabis should be legalized or at least delisted as a schedule I drug. Nicotine and alcohol are regulated, taxed, and routinely enjoyed, providing a blueprint for the deregulation of other drugs that are supposedly less noxious.3 However, these licit addictive drugs lead to serious social and medical consequences. For example, alcohol accounts for 5.1% of the global burden of disease and injury as measured by disability-adjusted life-years. We should be careful in extrapolating long-term consequences of cannabis legalization.
Goldman D. America’s Cannabis Experiment. JAMA Psychiatry. 2015;72(10):969-970. doi:10.1001/jamapsychiatry.2015.1332