I find drug abuse has become a major threat to humanity. Being one of the causes of crime, causing disorder and security, degeneration of the race, human dignity, undermining of family happiness, affecting health and especially infectious diseases. transmission of HIV / AIDS in the community; Consequences and harms caused by drug addicts cause serious impacts on economic development, threatening the stability, prosperity and longevity of each nation and each ethnic group. what's your opinion 
Physiologically, it depends on what drugs you take. There are stimulants and depressants.
Socially, it destroys the life of people who take and get addicted to it. If the user has a family, a wife and a kid most cases they end up having no parents to grow up with or greatly hate them. Users usually are incapable of thinking right so they might be get jailed or be killed because of it.
With the HIV part, I doubt though expect if drug users share same injectable needle or the have sexual intercourse while intoxicated.
