I believe it is progression. In my case, when beer didn't cut it any more, I did beer and shots of whiskey. Eventually that didn't do it anymore and I went to 100% mixed drinks, no beer at all.
Even that eventually failed me, and I went to bourbon & soda AND a shot of Jaegermeister!
Oh yeah and occassionally some illegal drugs too!
So don't let your self go any farther, from this alcoholics viewpoint, it does not get any better.