In the restoration process I have found the medical disease concept to hinder progress and healing (yes, healing) when used as a shield against personal responsibility and accountability. Too often I have heard words to the effect that "I have a disease/allergy and what I do is not my fault. I can't help it. I am a victim." Sort of like the excuses Adam and Eve gave God for their poor choices in the Garden of Eden.
From another perspective, if I consider alcohol and substance abuse to be sinful behavior and manifestations of spiritual unsoundness then I only have to turn to the Bible to find the "plan of treatment" needed to achieve the desired "cure." If I am dealing with a strictly medical condition then I must look someplace other than the Bible to find the required medical regimen. However, the Bible does offer guidance that can be applied even under these circumstance. For instance, read the story of King Asa in 2 Chronicles 16:12-13 and the guidance contained in James 5:14-15.
Regarding the concept of healing, is healing limited to only medical conditions? Does the concept not also extend to correcting spiritual deficiencies/deformities? So, in the context of Matthew 13:15, Luke 4:18, John 14:20, James 5:16, and 1 Peter 2:24, I see no inconsistency in applying the concept of healing to alcohol and substance abuse issues even when considering them to be consequences of choice as opposed to a medical condition.
To me the Bible is quite clear concerning the role that choice plays in my sinful behavior with the concept being most clearly expressed in Deuteronomy 30:15-20. I quite literally choose between the blessing or the curse, between life and death.
Finally, I do not consider belief in the disease theory to be a heaven or hell issue in and of itself solely determining where one will spend eternity. What my experience has shown, however, is that belief in the theory can be an obstacle to truly breaking free from satan's enslaving bonds of drugs and alcohol. In my own life any "evil or destructive tendency or state of affairs" can usually be traced to the "germs" of selfishness, rebellion, hedonism, etc., not some medical condition. I choose what I choose and I reap what I sow.