Addiction Is a Brain Disease

A core concept that has been evolving with scientific advances over the past decade is that drug addiction is a brain disease that develops over time as a result of the initially voluntary behavior of using drugs. The consequence is virtually uncontrollable compulsive drug craving, seeking, and use that interferes with, if not destroys, an individual's functioning in the family and in society. This medical condition demands formal treatment.

We now know in great detail the brain mechanisms through which drugs acutely modify mood, memory, perception, and emotional states. Using drugs repeatedly over time changes brain structure and function in fundamental and long-lasting ways that can persist long after the individual stops using them. Addiction comes about through an array of neuroadaptive changes and the laying down and strengthening of new memory connections in various circuits in the brain. We do not yet know all the relevant mechanisms, but the evidence suggests that those long-lasting brain changes are responsible for the distortions of cognitive and emotional functioning that characterize addicts, particularly including the compulsion to use drugs that is the essence of addiction. It is as if drugs have high-jacked the brain's natural motivational control circuits, resulting in drug use becoming the sole, or at least the top, motivational priority for the individual. Thus, the majority of the biomedical community now considers addiction, in its essence, to be a brain disease: a condition caused by persistent changes in brain structure and function.

This brain-based view of addiction has generated substantial controversy, particularly among people who seem able to think only in polarized ways. Many people erroneously still believe that biological and behavioral explanations are alternative or competing ways to understand phenomena, when in fact they are complementary and integratable. Modern science has taught that it is much too simplistic to set biology in opposition to behavior or to pit willpower against brain chemistry. Addiction involves inseparable biological and behavioral components.