Your assertion that drug addiction is a brain disease (Nature 506, 5; 2014) is a contentious oversimplification — akin to always blaming a car crash on the car alone.

By this analogy, addiction is the car crash and the brain is the vehicle: the person driving it contributes a psychological component, the others on the road represent social factors, and road conditions correspond to the environment. To promote any one of these as the prime cause of addiction, as in the brain-disease model, overlooks the importance of the other components.

There is a risk that such a reductionist biological view could hinder the development of solutions for addiction. It could also undermine a considered response to the issue of politically driven bans on the use of animals in addiction research — itself a topic that has important social, psychological and environmental contributors.