(ATLANTA) -- "I apologize." That's what CNN's chief medical correspondent Dr. Sanjay Gupta said about marijuana on Thursday.
For years, he spoke out against the drug, which the U.S. government classifies as one of the most dangerous illicit substances that have "no accepted medicinal use and a high potential for abuse."
Now, after investigating the plant for his upcoming documentary Weed, he's come to the conclusion that he may have been wrong.
"We have been terribly and systematically misled for nearly 70 years in the United States," he wrote.
Gupta decided to take a scientific approach to evaluating the drug, going back to the original research that led to it being classified as a "schedule 1" substance, on par with heroin.
Pot was originally classified as a dangerous drug in 1970, after the recommendation of Roger O. Egeberg, a doctor who was the assistant secretary of health at the time.
"Since there is still a considerable void in our knowledge of the plant and effects of the active drug contained in it, our recommendation is that marijuana be retained within schedule 1 at least until the completion of certain studies now underway to resolve the issue," Egeberg wrote.
In an article about his own investigation, Gupta cites research from before marijuana prohibition, from 1840 to 1930, an era when scientists looked at the medicinal value of the drug.
Nearly all studies on illegal drugs today look at the harm they might cause, not the potential medicinal purposes. According to Gupta, about 6 percent of marijuana studies look at the benefits of the drug. The rest focus on the potential negatives.
He makes a case for medicinal marijuana, pointing out that someone dies from an overdose of a prescription drug every 19 minutes. Meanwhile, he couldn't find evidence of a single marijuana overdose.
His look at pot could carry a good deal of weight. Many doctors have touted the benefits of medicinal marijuana for years, as well as its relative harm when compared to legal drugs like alcohol and tobacco.
More than half of Americans already support marijuana’s full legalization.
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