The Merriam-Webster Online Dictionary defines disease as “a condition of the living animal or plant body or of one of its parts that impairs normal functioning and is typically manifested by distinguishing signs and symptoms.”
Let’s take a quick look at addiction based on those criteria.
First of all, it is definitely a condition of the body or one of its parts. It creates changes in the brain and some other portions of the body that impair normal functioning, and that in some cases fail to return to normal, even after the disease is arrested by abstinence. It is manifested by signs such as abnormal behavior (often including psychosis), an unhealthy fascination with drugs, including alcohol, behavior outside accepted limits of morality and legality; and symptoms such as tolerance to the drugs’ effects, deterioration of organs and systems, and in most cases a withdrawal effect when the drugs are withheld.
The question of coming and going is almost a contradiction in terms. The disease can be arrested. That is, the signs and symptoms will eventually subside when the drugs are completely out of the system, but the disease is still there. Some immediate relief is accomplished as soon as withdrawal is over — a few days for alcohol and some drugs, up to two to three weeks for some others. During the period while the brain and other organs are recovering from exposure, there will be occasional periods of discomfort that are interspersed with times when the symptoms are slight or non-existent. This period of post-acute withdrawal can last for months, but the progression is always toward feeling better, as long as drugs are not put back in the system.
However, “arrested” is not “cured.” If drugs (and not just the drug of choice) are re-introduced, the changes in the brain that comprise the physical part of addiction will return quickly and the addiction will again become active. When we combine that with an addict’s instinct to use drugs whenever he or she doesn’t feel good, it means that stress, poor health, failure to maintain a healthy frame of mind, over-response to post-acute withdrawal symptoms, and just plain depression can lead to using, and thus to the reactivation of the disease. It is rather like diabetes, which can be arrested with exercise, diet and medication, but is still in the wings, ready to pounce if we get sloppy about taking care of ourselves.
So you can see that addiction and alcoholism definitely meet the criteria of a disease, as both the American Medical Association and American Psychological Association declared more than half a century ago. There are identifiable changes in the body, and identifiable impaired function, both physical and psychological. Furthermore, the progression of the disease is always “downhill,” and almost invariably results in death, unless something else kills us first — often physical deterioration aggravated by the disease.
Addiction is not voluntary, but once we have passed the post-acute withdrawal phase, we either choose to relapse, or to remain abstinent. Relapse occurs long before we pick up, and is the result of either a lack of commitment to sobriety, and/or failure to maintain our physical and emotional health by doing for ourselves the things that only we can do: make use of our supports and follow “to any lengths” the suggestion of a proven program of recovery.