Because of the popularity of 12 Step programs (mostly because they have been the most effective method for treating end-stage addicts), we tend to throw everyone into these programs who have substance abuse problems. It becomes another form of "Kill 'em all, let God sort 'em out" approach (I remember 20 years ago seeing those T-shirts, and I am glad the fad went away).
What it ends up doing is clogging up meetings with loads of unwilling people, but it also does no favors for people who are 'medicating' another problem which isn't really addiction.
If we follow the Big Book carefully, we see how the addict's central problem is his resentments and guilt, both of which stir up fears which are then 'coped' with using the addictive substance of choice. However, there are those who's real problem are not so much about their memories as they are about their overall disposition.
Bill W., as it turned out, struggled with depression in addition to a long life of destructive drinking. We have all encountered people in the program with moderate to severe mental illness, which the 12 Steps really cannot treat.
I have run into several cases where people with Asperger's Syndrome use alcohol or drugs to break out of the 'shell' of Autism. The problem here is that addiction often distorts us and leaves us with much of the same social awkwardness that an AS person suffers with. And, just as AS people can be inconsiderate and lack empathy, so addicts can even one-up them into profound callousness and egomania.
So, while people with certain organic mental disorders can become substance and behavioral abusers, it is wrong to lump their problems into the general category of addiction as if they are completely undifferentiated. Think about it: if the program equates sobriety with a return to 'sanity,' what are we offering these people?
They need treatment for their underlying problems as much if not more than they need help with 'addiction.' I'm not saying that the 12 Steps are not helpful. What I am saying is that the 12 Steps will not work if the underlying problem is not effectively managed. Otherwise, relapse is an unavoidable reality.
Since we live in an age where we have so many resources, folks who are trying to get sober may well benefit from an initial evaluation. Getting a handle on the whole problem is important, and trying to treat true mental illness with 12 Steps is like trying to a migraine with an aspirin.