Yes, many psychologists consider alcoholism a disease. One problem though -- psychologists don't have M.D. at the end of their name. That's right, psychologists are not medical doctors. In fact, you don't even need a doctorate to become one. Many psychologists have only their Masters' in psychology. So honestly, I don't put too much stock into what a psychologist decides to call a disease.

The definition of "disease" is in two parts:

First: "a disordered or incorrectly functioning organ, part, structure, or system of the body..."

Then classification by cause: "...resulting from the effect of genetic or developmental errors, infection, poisons, nutritional deficiency or imbalance, toxicity, or unfavorable environmental factors; illness; sickness; ailment."

So certain qualifying EFFECTS of alcoholism (cirrhosis, etc) can be considered a disease, but the alcoholism itself does not qualify. In the same way, lung cancer and emphysema are diseases, but smoking a pack a day is not.

I would hesitate to call depression a disease as well, and think disorder would be a much more appropriate term.

In any case, none of this is to minimize the sheer destruction any of these things can wreak in a person's life. Nothing I've said is an attempt to marginalize the difficulties faced by alcoholics, smokers, or any other ailment. However, smokers and alcoholics are not victims either -- the alcohol doesn't pour itself down a person's throat. The cigarette doesn't light itself up. Make no mistake, there is a choice. It may be an insanely difficult choice, but it IS a choice.* And that's the real tragedy -- that those afflicted by these problems do it to themselves day after day, most of them know they're killing themselves, and most of them can't seem to build up the willpower to stop.

* As an economist, I argue that everything is a choice. You don't HAVE to do anything. You'd just rather do that thing than the alternative.