Passage of a law that defies intrenched local custom evokes the threat of adverse social repercussions. That statement is amply supported by a study Westermeyer1 conducted between 1965 and 1975 in three Asian countries where anti-opium laws were enacted or enforced despite the fact that opium use had been traditional.
In their colony of Hong Kong, the British abandoned a laissez-faire policy and began enforcing narcotic laws after World War II. Before that time, opium addiction had been the only form of narcotic addiction known in the colony. By the 1960s, heroin became the favored drug among new narcotic users, and many persons formerly addicted only to opium had switched to heroin. The trend continued; a decade later, opium addiction continued to wane while heroin addiction was still increasing.
In Thailand, pressures from international organizations caused passage of a law whereby government physicians became obligated in 1959 to treat
Hussey HH. Prohibition of Traditional Addicting Drugs: Social Repercussions. JAMA. 1976;236(13):1501. doi:10.1001/jama.1976.03270140053027