Editor’s Note: “Weed 7: A Senior Moment” premieres Sunday, August 6, at 8 p.m. ET/PT on “The Whole Story with Anderson Cooper.”

CNN  — 

Prior to filming our first documentary on cannabis a decade ago, I was highly skeptical about its use as a medicine. I had even written a story for Time magazine a few years earlier to make the case that the evidence simply wasn’t there.

But, as so often happens when we start to dig into things, a different picture started to emerge. I traveled the world, visited tiny labs and, most important, spent time with patients — even young children — who changed my mind. I came to the realization that in some cases, not only did cannabis provide relief, it was the only thing that did so.

Yes, there are real risks, as with most things. And of course, it’s not a panacea. Nothing is.

While it is not something that will work for everyone, that should not mean it isn’t available to anyone.

Over the past few decades, we have experienced one of the most significant and uneven legal evolutions ever seen in the United States. Up until 1996, there wasn’t a single state that had legalized cannabis for any purpose, but now 38 states and the District of Columbia have some form of cannabis legally available, while it remains a Schedule I substance federally: “drugs with no currently accepted medical use and a high potential for abuse.“