Francis told delegates to a drug-enforcement conference in Rome that even limited attempts to legalize recreational drugs "are not only highly questionable from a legislative standpoint, but they fail to produce the desired effects.... Let me state this in the clearest terms possible: the problem of drug use is not solved with drugs!"
If the drug you're using failed to produce the desired effects... maybe you're using the wrong drug? Or not enough? Or too much? And most of the "problem[s] of drug use"—black markets, gang violence, mass (and racist) incarceration, adulterated drugs—stem from drug prohibition, not drug use. Solve the problem of prohibition and you'll solve most of the problems of drug use.