Your poor son, if he thinks it's a disease over which he has no control and that most people die of it, because that isn't my experience. If only you and your son would read around the main forums, where the addicted people post. There are many, many people staying sober, with SR only, plus others with a variety of, and a mixture of other methods.
Your son needs hope, to see that many people recover, and that he can too. Why isn't your son posting in Newcomers on SR, there's lots of hope and support available. Your son is being victimised by his AV.