Even aside from the general philosophical argument for the decriminalization of all drugs, there is a lot of evidence that the decriminalization of mushrooms in particular could be beneficial for a lot of people. In fact, the Food and Drug Administration has designated psilocybin a “breakthrough therapy” for depression. According to the company working toward approval of medicinal psilocybin, this means that “preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies.” “Breakthrough” status means that the therapy can move faster along the pathway to approval. As Reason notes in a column on the issue, a study sponsored by the British life-sciences company COMPASS Pathways found that its dozen participants experienced major improvements in their depression thanks to psilocybin. After one week, their mean score on the Quick Inventory of Depressive Systems, which ranges from 0 to 27, had dropped from 19.2 to 7.4. After three months, the mean was 10.0, which was 48 percent lower than the baseline.

Another study suggests that mushrooms are also helpful for the mental health of those who are suffering with life-threatening illnesses. In 2016, a Johns Hopkins study reported that cancer patients who had received psilocybin experienced an average 78 percent reduction in depression and an 83 percent reduction in anxiety.