Having a personality which is obsessive/compulsive results in doing things to excess which you know are not good for you, yet you are helpless to control yourself. This is not just boozing it up at weekends or eating too much on a Sunday. It's a condition, whereby 'stop' signals are completely blurred; a self-destructive urge which you simply cannot fight. Anorexia and bulimia are the same. Nobody chooses to become obsessive about alcohol/food/smoking/drugs. It is something which I believe, in the future, scientists will discover is caused by a brain blip; a genetic thing which at the moment, is ridiculously being "dealt with" by the government as though it is caused by over-indulgence. If being thin was a matter of eating less, everyone would be thin. Same with alcoholism; if it was easy to stop, everyone would just stop. The addiction is only part of the issue; the urgency and obsession/self-destruction which the person feels, and is helpless to fight against, is far less understood, but is the main cause of the disease.