Sunday, November 6, 2011

New Insights on Old Observations about Addiction

I have yet another media link to recommend. Charlie Rose, on his PBS program, has commenced a second series designed to provide new insights on the brain and its connection to human experience, and the first installment provides a great overview, led by neuropsychiatrist and Nobel laureate Eric Kandel. The panelists are Gerald Fischbach (neurology), Thomas Insel (of NIMH, on psychiatric disorders), and – most relevantly to this blog – Nora Volkow, director of the National Institute on Drug Abuse. With her unmistakable accent (the outgrowth of growing up in a Russian family while living in Mexico), she is a remarkably articulate explainer of addiction from a neurobiological standpoint.

What often strikes me is that new brain-based descriptions of how addictions develop and operate often dovetail with old observations. Those of us who have been working with alcoholics/addicts for a long time have tended to develop conclusions based on our collected observations. Now, we have some possible ways to understand the neurobiological mechanisms that may underlie these observations. For example:

[Observation] Even people who express a sincere wish to abstain from substances, or who think they should be able to exert enough “willpower,” usually find that they return to the kind of behavior that they have sworn off. [Neurobio Explanation] The process of developing an addiction includes developing a linkage between drug- or alcohol-related stimuli and a drive toward addictive behavior, co-opting the same reward circuit that drives us toward doing things we need to survive (such as eating and procreating). In addition, the repeated intrusion of drugs into our brains injures the prefrontal cortex, the part of our brains that helps us exert appropriate caution before acting.

At first, individuals enjoy getting high when they choose to use alcohol or addictive drugs. For those who become addicted or alcoholic, however, substance use has the primary function not of feeling good so much as feeling normal or OK. Neural reward circuits “light up” in real-time brain scans of non-addicts when they use the substance, but those who have developed addictions show little or no change. This fact, however, does not extinguish their urge to use, which is now driven by other factors.

With rare exceptions, addicts/alcoholics do not “rewind” and return to an earlier, more normal pattern of use. A purely learning/unlearning model does not seem to apply. Although learning and memory clearly play a role in the development of addiction, changes in brain circuits persist. Even in the absence of active substance use, the disorder is typically chronic.

A 30-day rehab alone is rarely successful if not followed by frequent and consistent follow-up, in some combination of support groups, professional contacts, and safer living environments. Brain changes resulting from months or years of addictive drug use endure for months or years; short-term treatment is far short of what’s necessary to reverse or compensate for those changes.