What say you?
Addiction to substances (e.g., booze, drugs, cigarettes) and behaviors (e.g., eating, sex, gambling) is an enormous problem, seriously affecting something like 40% of individuals in the Western world. Attempts to define addiction in concrete scientific terms have been highly controversial and are becoming increasingly politicized. What IS addiction? We as scientists need to know what it is, if we are to have any hope of helping to alleviate it.
There are three main definitional categories for addiction: a disease, a matter of choice, and self-medication. There is some overlap among these meta-models, but each has unique implications for treatment, from the level of government policy to that of available options for individual sufferers….
To get a bit more specific, every experience that has potent emotional content changes the NAC (nucleus accumbens) and its uptake of dopamine. Yet we wouldn’t want to call the excitement you get from the love of your life, or your fifth visit to Paris, a disease. The NAC is highly plastic. It has to be, so that we can pursue different rewards as we develop, right through childhood to the rest of the lifespan. In fact, each highly rewarding experience builds its own network of synapses in and around the NAC, and that network sends a signal to the midbrain: I’m anticipating x, so send up some dopamine, right now! That’s the case with romantic love, Paris, and heroin. During and after each of these experiences, that network of synapses gets strengthened: so the “specialization” of dopamine uptake is further increased. London just doesn’t do it for you anymore. It’s got to be Paris. Pot, wine, music…they don’t turn your crank so much; but cocaine sure does. Physical changes in the brain are its only way to learn, to remember, and to develop. But we wouldn’t want to call learning a disease.
So how well does the disease model fit the phenomenon of addiction? How do we know which urges, attractions, and desires are to be labeled “disease” and which are to be considered aspects of normal brain functioning? There would have to be a line in the sand somewhere. Not just the amount of dopamine released, not just the degree of specificity in what you find rewarding: these are continuous variables. They don’t lend themselves to two (qualitatively) different states: disease and non-disease.
In my view, addiction (whether to drugs, food, gambling, or whatever) doesn’t fit a specific physiological category. Rather, I see addiction as an extreme form of normality, if one can say such a thing. Perhaps more precisely: an extreme form of learning. No doubt addiction is a frightening, often horrible, state to endure, whether in oneself or in one’s loved ones. But that doesn’t make it a disease.