There were 140,000 past year initiates of heroin among individuals aged 12 or older in 2010 in the U.S., showing no significant change from 2002 & 2009 estimates.
The combination of Xanax and alcohol can potentially result in death, as both are central nervous system depressants that slow activity in the brain, so they should not ever be taken together.
Methadone withdrawal is so burdensome to those who are addicted and dependent to it, that someone who is using it may think that they will be on it for the rest of their lives, or at least for many years.
Smoking crack sends large quantities of the drug to the lungs, which creates an immediate and intense euphoric effect.