Great question, thanks for writing. Your wife is going through a difficult period, but I think you are right on the money with your armchair assessment of the problem (you do know her well). I agree that guilt has been a tremendous negative force in her life, and may be the primary motivator influencing her decisions and behavior right now. Based upon the description you provided, your wife not only has the guilt feelings throbbing internally, but the people she was closest to in her life (i.e., her sisters) did all they could to overtly and covertly reinforce the guilt.
However, her doctor was also correct in that any medical intervention - or psychological, for that matter - should begin without the anesthetizing effects of alcohol clouding her mind. My overall advice is to get her to a mental health professional, but a talk therapist rather than a psychiatrist for the time-being. A prescription may be necessary (especially in the short run to help her rest at night), but I would rather a therapist be the center of the wheel for her treatment. Here's why:
A talk therapist will have more contact with your wife and will be best able to gauge her diagnosis, her treatment progress, and her mental health needs. A psychiatrist will be happy to help with the medical management, but they tend to rely upon the evaluations done by the therapists because the therapist is usually more thorough in the data they consider. Given your wife's extensive history both with emotional pain and with sleeplessness, there are a lot of variables to consider.
Lastly, you should be on the lookout for other unhealthy coping strategies your wife may employ while the process is still in its infancy. Once you remove alcohol AND begin to tear away at the emotional scabs holding back the pain of her youth, she may turn to other means of self-soothing. She may begin to shop a lot, for example. Or maybe begin to take other pills (maybe over-the-counter medications) to try to keep the pain and frustration at bay. Whatever the case, long-term alcohol use tends to seep into the brain and convince it that it will need SOMETHING to manage the burgeoning anxiety.
I wish you well. Your wife has some very tough work to do - it is difficult to open yourself to the emotional torment that you felt would utterly consume you when you were younger (which is why it was potent enough to disrupt sleep and call for wine), but there is hope. Treating trauma like hers will take some time, but it is relatively routine - a good therapist should know what to do and will begin immediately.
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