I have no scientific proof. But I offer my 22 years of experience living with one.
YES. The personalities change!
And they seem to change in a very, very similar and predictable fashion. Read the posts here. After the alcoholic has been drinking a while, they seem to act very much the same. It seems to me many on this board have cameras in my house and are telling the same stories that are happening to me. The behavior is so similar I can't help but think it is a direct result of the alcohol abuse and/or the alcoholic gene.
And YES, my alcoholic wife has a personality change after drinking. And it lasts for a day or two after drinking. It is easy to see, not so easy to deal with.