Allegations from anti-pot proponents that cannabis use by adults causes serious harms are unwarranted and unproven. So says one of the nation’s leading marijuana researchers.
Speaking recently to the American Association for the Advancement of Science (AAAS), Dr. Igor Grant acknowledged, “There is no evidence for long-term damaging effects in adults.”
He ought to know. Over his professional tenure, Grant has authored several peer-review journal articles specific to the health effects of cannabis, including a 2003 report which concluded that the long-term heavy use of pot was not associated with the “substantial, systematic, and detrimental effect of cannabis use on neuropsychological performance.”
Grant also served as the director of the University of California Center for Medicinal Cannabis Research, during which time he oversaw the completion of a number of FDA-approved clinical trials assessing the safety and efficacy of whole-smoked marijuana. In 2012, he co-authored a summary of these trials for the scientific journal Open Neurology.
“Based on evidence currently available the Schedule I classification is not tenable; it is not accurate that cannabis has no medical value, or that information on safety is lacking,” the article concluded.
Speaking at this year’s AAAS meeting, Grant said that smoking cannabis long-term is associated with bronchitis. But he cautioned that purported links between cannabis and the onset of psychiatric disorders like schizophrenia have yet to be established. He also warned that allegations that cannabis harms the brain “are very weak at the moment.”
Grant further acknowledged that the present Schedule I classification of the plant is inappropriate and severely hampers investigators from studying its effects.
“In the U.S. there are certainly a number of hurdles and processes one has to go through, and I think this does inhibit ordinary investigators who don’t have the means or the knowledge or the staying power to get through the system,” he said.
On February 11, a federal judge for the Ninth Circuit heard closing arguments in a motion challenging the constitutionality of marijuana’s Schedule I classification. The case marks the first time since 1973 that a federal judge has weighed evidence in regard to whether there exists a “rational basis” for the government to maintain the plant’s prohibitive status The judge is anticipated to rule on the matter by mid-March.