One thing I am curious about with this research is how they would get reliable numbers for high functioning opiate addicts. Addiction is really a spectrum from "no dependence on the drug and no negative life consequences" to "high dependence on the drug and many negative life consequences". I'm sure that many people fall in the middle where they continue to responsibly live their lives while still being dependent on a drug that they may wish to quit, but can't because the withdrawal is too much. I also would not be surprised if many of these people did not seek out help and tried to hide their problem from others due to the major stigma associated with being addicted to opiates, not to mention those who are dependent on opiates but in denial about their dependence.