The risks of tobacco and alcohol are well documented (cannabis not so much, but there are known and proven risks) and the evidence of this is also prevalent in modern society - people still continue to use these substances even though they know the risks. Why should I pay for the treatment of someone who full well knew what they were subjecting their body to, yet continued doing it? What I'm saying is, people shouldn't be treated for misuse/negative effects of drugs. That's the responsibility of the patient, not the healthcare provider. Sure, it can be legal, but don't ask the 'system' to help you out when it screws your life up - normally, it's of your own doing, not anyone else.