As we've said in the past, it depends on how one wishers to define "disease." The term is highly fluid, constantly expanding to include normal variations and things one might term "conditions" (mainly for insurance purposes), and lacks any natural definition.
Is it helpful to consider addictions brain disease? Addiction Is Not a Brain Disease - The idea that drugs and biology are to blame for addiction has done more harm than good.
Related, is being fat a disease?
Related, Dalrymple discusses More Tools, Less Understanding - Thoughts on the surgeon general’s report on addiction. He is wrong about one thing: drug addiction is not a result of pain meds for people with serious pain. That is very rare.
My view is that substance abuse derives from one simple effect: Some people like it a lot and it makes them feel better than they otherwise feel. Any physiological dependence part is secondary to that. Also, I am not too keen on the criminalization of drugs. The "War on Drugs" has accomplished little good and has many unintended and unfortunate consequences.
Related to that: The Other War — Drugs — May Soon Force Trump To Put Up or Shut Up