In recent years, addiction has been understood to behave differently than previously thought.

Rats who become addicted to cocaine or morphine drip are often raised in confined and stressed environments. Experiments like the Rat Park show us that addiction is not as much drug-induced as it is stress-induced. When rats addicted to morphine drip are placed in a larger and richer environment, they cease to self-administer morphine.

Heroin addicted soldiers returning from vietnam appear to drop all addictive behavior now that they are no longer in the stressful environment (pdf).

Psychedelics appear to greatly affect anxiety and from what I can tell psychedelic users are more adept at dealing with stress. Could it simply be that by improving the quality of life of addicts, they no longer need the fix to feel good?