We can draw an analogy to a condition like diabetes: It doesn't little good to lecture someone about the importance of good eating habits and regular exercise to prevent diabetes if their condition is genetically based (although of course diet and exercise can still help to control it), but it does a tremendous amount of good to talk to an individual about environmental factors if his or her diabetes is caused by poor eating habits (Tomer etal, 2001).
The current research on alcoholism suggests that it is indeed a combination of poor genetics and destructive behavior, with a greater emphasis on the former than the latter. The fact that alcoholism is to some extent under the control of the individual is important in terms of being able to reverse the condition - and for the individual's taking responsibility for his or her condition (something that would be entirely inappropriate for a disease like Tay-Sachs, which is entirely genetic and is not in any way linked to an individual's voluntary behavior). (Dawes etal., 1999).
It may sound somewhat odd to think about alcoholism as "learned behavior" - a term that we are more generally likely to apply to an activity like riding a bicycle or doing calculus. But a large body of literature (viz. Dawes etal., 1999) demonstrates that dysfunctional behavior (even highly dysfunctional behavior) can be learned as well. Any activity that is at least initially rewarding (or that is initially more pleasurable than the