cocaine was cheap and easy available a century+ ago (for example the original Coca-Cola was an over-the-counter headache treating mix which contained alcohol and cocaine). Didn't lead to much positive impact. (Note: i'm for full unlimited legalization, though not because it is that good, it is just that 1.the adults have the right to practice Darwin theories and 2.the Prohibition is really bad)
Maybe with robust social safety nets and mental health services available (Portugal model).