Yes, I lived with a girl a long time ago who dropped out of her Phd program and was drinking nonstop b/c of her depression over it. It was impossible to deal with
Its not an illness, unless you define it broadly as it does have symptoms, its a more a guilt cycle that people get into and many are also suffering from depression and are self medicating.
The illness approach is the most useful approach towards the treatment of an alcoholic most say, but its not even in a pimple on the butt. Its a cognitive cycle that people get into, but yes, brain chemistry is altered and there is addiction and you can die if you are a severe alcoholic if you quit drinking.
THe addiction as a disease is very debatable, again it is a useful treatment approach as well as helping laypeople understand the cyclical abuse of alcohol despite the overwhelming consequences.