It starts as a choice, so is in no way a diseases imo.
Circumstances can then lead to it becoming a habit or addiction. But unless you're a heroine baby you aren't born with a taste for it. I sympathies with those that become enthralled in any addiction as they all ruin lives. But classing it as a disease is a discredit to true illnesses imo.
I'm with this and a number of the other responses. There are choices taking place at various stages. I accept there comes a point when the ability to make rational decisions reduces but for me it is not a disease. Too many people want to absolve themselves of responsibility for their actions now.
I think Hobbit called it an addiction and should be treated as such. I think that is a good assessment. Incidentally, I do not underestimate the impact or destruction it can have.