More than 30 states have medical marijuana programs — yet scientists are only allowed to use cannabis plants from one U.S. source for their research. That's set to change, as the federal government begins to add more growers to the mix.
After more than 50 years, the federal government is lifting a roadblock to cannabis research that scientists and advocates say has hindered rigorous studies of the plant and possible drug development.
Since 1968, U.S. researchers have been allowed to use cannabis from only one domestic source: a facility based at the University of Mississippi, through a contract with the National Institute on Drug Abuse (NIDA).