Tennessee lawmakers picked back up the debate over medical marijuana Tuesday by hearing testimony about one claimed benefit of cannabis — lowering anxiety from post-traumatic stress disorder.

The claim is that marijuana cut PTSD with fewer side effects than prescription drugs.

Dr. Suzanne Sisley says she was initially skeptical. But then she talked to veterans about it.

"It's clear that in states that have medical cannabis law, patients are choosing cannabis as a safer alternative," she told lawmakers.

Sisley practices medicine in Arizona, which has allowed medical marijuana for five years. She also oversees doctors in 13 other states that are prescribing cannabis.

One study she presented showed marijuana cutting PTSD by 75 percent. Another claimed that states with medical marijuana have 25 percent fewer deaths from opioids.

Backing her up was Roberto Pickering, an Iraqi War veteran from California who says he was able to stop taking more than a dozen prescription drugs and get a full night's sleep again after he started using marijuana.

But Tennessee lawmakers remain skeptical.

Springfield Republican Sabi Kumar, a doctor himself, noted that many other studies show a downside to cannabis. And, he pointed out, there are few guidelines for using marijuana medicinally.