Your wife is not alone. I was diagnosed as bipolar in 2007 at 40 yo. All my formative years, teen years and adult years have been marked with depression, suicide attempts, 20 moves to 3 states and all the while periods of heavy drinking, periods of abstinence from alcohol and weed, which later led to other things.
Bi polar left me uninhibited, no thought of consequence or other people. When I would come down, I would get drunk to deal with the shame, guilt and remorse. Both diseases are fatal left untreated. I take my medication, go to a therapist, psychiatrist and most important, AA.
AA and my sponsor were the catalyst in my acceptance of the MI. At first, I resisted, which is not unusual in alcoholism or bi-polar. At this moment, for the first time, I know this is the right path.
Not sure what your decision will be but just know that she is in the solution, trying to get well.