I didn't wait for any official medical diagnosis on my late XAH, Lord knows I had seen enough alcohol induced dementia and W-KS over the years and the signs were all there for me.
Seeing him sitting at the home bar, with a glass of whisky and a stubbie of beer at 7am while he informed me that this was how WE were spending his retirement was my big wake up call.
Some way to celebrate a 27th wedding anniversary.
I walked out and went flat hunting and within the week I was gone.
He went thru his superannuation, wrecked a car, almost burnt the flat down a few times, and forgot his needles or/and eating. He didn't enjoy his retirement at all, and for years it was all my fault for leaving him.
By the time he died last year, I had been well over the pain and guilt of what I did, and believe if I had stayed I would have beaten him to the grave by a number of years, so it was a lifesaving decision for me.
I second the "go for divorce" advice.