Five patients are filing suit against the state of Colorado after the Board of Health decided not to approve cannabis as a treatment for post-traumatic stress disorder (PTSD).

“The board in effect established a standard that was impossible to meet. They insist on having a federal study, which in effect is a futile standard,” a lawyer for the patients told The Associated Press.

According to the board, there simply isn’t enough evidence and anecdotal reports don’t count.

The request was denied by a 6-2 vote back in July, after which veterans reacted with boos and hisses. They said that cannabis was a lot safer than the antidepressants and opioids being handed out at VA clinics.

Keeping cannabis medical in Colorado is important due to how recreational cannabis is taxed versus the medical supply. Furthermore, medical patients can carry with them twice as much as a recreational user. But medical patients need a doctor’s approval and so far the State’s laws, which don’t list PTSD as a condition that can be alleviated with cannabinoid treatment, bind doctors.