I am not sure this article necessarily reflects local drug culture. From observation, the increases in seizure are much more likely down to the harassment and searching of Hong Kong's youth. I have noticed a huge increase in 'stop and search'. I have seen many more incidents of clusters of police around teens, often at MTR exits. Speaking to friends, they have told me their teenagers (particularly boys) are often stopped, questioned and having their bags gone through. So any decline is due to the youth of HK being cowed and avoiding trouble. It's not right. I'm no supporter of teens taking drugs, education rather than oppression would be a better route.