Most people don't think of themselves as having a "mental illness"--it's such a negative term. But that doesn't mean they don't have one. Not saying that you did, Dagmar... just that self-diagnosis is highly unreliable. Also, there is a difference between major mental illnesses and other types of disorders.
alinnell, there are, anecdotally speaking, two kinds of alcoholics. "Binge drinkers" may have long periods where they don't drink, or appear to drink like a normal person, but then they go off the rails one day and just keep going. Lost Weekend. They often black out while on a binge and come to in a strange city with strange people.
"Maintenance drinkers" or "daily drinkers" usually don't drink the way binge drinkers do--instead, they just keep a little buzz going all day long, as in, from the first thing in the morning, and then increase in the evening. However, the amount they drink does tend to escalate over time.
Often these two types like to point to the other type as being the "real alcoholics."