Hi MCE - I'm a recovering alcoholic with depression and OCD (probably ADD, but haven't been tested). It's not uncommon for people with mental/emotional issues to self-medicate.
Anti-depressants aren't addictive or mood-altering. People can't get high off them - there is no craving or physical dependence like with drugs/alcohol. I think the reason most rehab centers don't deal with psych meds is because it requires an enormous amount of money to have a psychiatrist and medical staff and equipment on hand..... and it take times to do the testing and evaluation.
But you're right - many of us do need more than just a place to get sober. I hope your wife can get some answers and can begin a new and better life without alcohol.:ghug3