Please also be aware that any Psych Dr worth their salt will usually insist on the client being free from alcohol and/or drugs at least 6 months as alcoholism can and does mimic other mental illnesses.
They are much more aware of this these days than when I got sober, and thus I did not see a Psych Dr until 9 years of sobriety when I truly believed I was going totally insane. The first thing I did was find one that literally was a specialist in addiction and had worked with and was working with recovering A's.
The first thing she did was put me in a regular hospital for a complete physical to see if I was chemically imbalanced and to see what else might be going on physically.
I was eventually diagnosed as Bi Polar and then was, as stated above in very intense one on one work with her 2 to 4 hours a day for months. That was 1990 and even back then it took almost 5 years before we/she found the correct medication and dosage for me. I have been in great shape in being able to deal with my Bi polar now for years. Bear in mind though that since then there are many more medications available and it is still a 'trial and error' kind of treatment, as one that works great on one person may not work at all on another.
My Psych could never really say which came first my Alcoholism or my Bi Polar but strongly suspected that I was Bi Polar first and 'self medicated' for years to function and thus slipped into alcoholism, as the propensity for it was already in my gene history.
You'll know if you/he has found one if one of their first questions is about if he is still drinking and/or how long he has been clean.
J M H O
Love and hugs,