A new study finds that enrollment in medical cannabis programs rose nearly five-fold between 2016 and 2020, as more and more states legalized the drug’s use for a range of different health problems. Researchers said that enrollment was clustered in states with medical-only cannabis reform, while it is flatlining or declining in states with legal recreational marijuana. This is mostly due to the fact that medical marijuana requires a visit to a doctor and a processing fee, thereby driving up costs, while buying recreational marijuana only requires proper identification and age verification. The study identified chronic pain as the most commonly listed condition on medical license applications, followed by PTSD, although another study showed that there’s scant scientific evidence showing that marijuana is effective for treating chronic pain. Chronic pain patients also happen to be targeted with cannabis ads. In addition, the study found that the proportion of medical cannabis patients listing conditions not supported by substantial evidence increased between 2016 and 2020, indicating that more studies must be done in order to determine whether medical marijuana is safe and effective. And it also suggests that we need more oversight and regulation of medical marijuana advertising to crack down on false claims and scams.