The Disease of Addiction
As Science Magazine put it in a 1997 article, “The addicted brain is distinctly different from the non-addicted brain … That addiction is tied to changes in brain structure and function is what makes it, fundamentally, a brain disease. A metaphoric switch in the brain seems to be thrown as a result of prolonged drug use.”1
The changes in structure and function occur at the molecular and cellular levels in the brain’s Limbic ‘reward” system, the network that experiences pleasure. It’s also a key component in learning, memory and motivation.
Brain changes associated with addiction, particularly the development of tolerance, result in a form of toxic learning in which addicts discount the negative rational consequences of drug use in favor of its positive emotional payoff. Deepening tolerance also requires addicts to continue drug use to stave off the physical and emotional pain and dislocation of withdrawal. The malignant motivation to take drugs as medicine to avoid withdrawal continues despite dramatically worsening physical, psychological and emotional repercussions. (For more, click on Dopamine: Learning, Memory and Motivational Toxicity).
The changes in addicts’ brain function literally alters the way they think, resulting in behaviors like denial, irrationality and obsessive drug use regardless of consequences. The addict brain is changed permanently, partially explaining the prevalence of relapse after treatment and why the disease of addiction becomes irreversible.