Obviously Troyer had a lot of health problems outside of alcoholism. The alcohol was probably to cope with his chronic issues. Hervé Jean-Pierre Villechaize (Fantasy Island) had a similar sad story that ended with suicide.
I was best friends with another little person who also killed himself. It's fuckin hard being that small. Even though it gave him money and fame, it's gotta be hard to hear "Hey! It's Mini Me!" over and over everyday.