I actually saw someone do this to themselves today.
I listened to them work themselves up to a rant, like an old locomotive gaining speed; their mind chugging and whistling along until what had started as good news was nearly overwhelmed with fear and suspicion. Certainly that's possible for anyone to do, but alcoholics seem especially prone to this kind of anxious over-thinking.
Listening to them I felt my arms pebble with goosebumps and I had butterflies in my stomach -- butterflies of gratitude, actually (I know how insipid and cornball that sounds, but truly, that's what it was) because listening to that poor soul create anxiety out of thin air I saw how clearly AA and the 12 Steps have helped me straighten out my thinking, and perhaps more importantly, become aware of how I think.
Drinking is the symptom of alcoholism; thinking is its home.