New Book Reignites Disease Model Debate

Thanks to Gina Suslick, NAADAC Govt. Relations Intern, for guest-blogging this post.

The argument about whether or not addiction is a "disease" has been raging for years, but it was recently rekindled by the release of a hotly debated book by Harvard psychiatrist Gene Heyman. Heyman proposes that ongoing addiction is fundamentally a choice that can be changed with the development of motivation, new knowledge and value systems. An interview with him can be read here, and a chapter from his book, Addiction: A Disorder of Choice, can be read here.

Other arguments support Heyman’s assertions, such as those who believe that “free will” is what leads to addiction. Since the addict is choosing to use the drug repeatedly, whether or not the end result is physiological dependence does not matter. Still others argue that it cannot be considered a medical illness because addiction, unlike Parkinson’s, cancer, or the flu, requires that you consciously decide to take a pill or pick up a needle in order for it to come to fruition.

Heyman’s book seeks to add epidemiological data to support the addiction-is-a-choice argument. He suggests that addiction is more a long the lines of dieting or going to the gym: you can be successful if you want to, and if you make the choice to do so. Heyman believes that people naturally want to consume too much of everything, whether it be food, television programming, or even drugs. He makes the point that most people who don’t become addicted to drugs do so based on the fact that they don’t want to become a drug addict. So, as an addiction professional, I have to ask myself, does this imply that those who are addicted are that way because they--at some level--want to be?

Heyman does not dispute existing scientific evidence that drug use alters the brain’s functioning. What Heyman wants to demonstrate is the fact that drug use (even addictive drug use), does not alter our underlying ability to think. Heyman believes that addicts can consider the consequences of their actions, and therefore stop using once they do a rational cost/benefit analysis. He seemingly agrees that the physiological changes involved with addiction--especially withdrawal--make it extraordinarily difficult for many people to do a cost/benefit analysis without some help.

Many addicted people I have interacted with are fully able to recognize the consequences of their actions (“If I spend my check on heroin, I won’t be able to pay rent, and will lose my housing”), but yet even with this recognition in mind, they cannot seem to end their drug use. It is true that at some point, those who successfully stop using become able to step back and look at the costs of what they have done for their addiction, but, as is pointed out in this Toronto Star article, there can also be varying levels of addiction. Whether or not addiction is, at its heart, best modeled as a disease or a choice, there's no question that many people with substance use disorders need professional help as they walk the bumpy road to recovery.

Yet one can't help but wonder if Heyman gives sufficient weight to the physiological changes that drugs cause in the brain and the rest of the body. One very recent study by NIDA and the Brookhaven National Laboratory involving cocaine users points to evidence that drug abuse can change the brain physiology enough so that the user cannot suppress the “craving” for a drug. Combined with lower ability to monitor behavior, this can indicate why some people are actually more vulnerable to taking drugs. This is because cocaine use alters the function of the anterior cingulate cortex (ACC), which is in charge of emotional regulation and behavior monitoring. Compared to those without cocaine use disorder, the cocaine users performed equally well on most tasks except tasks that require the regulation of behaviors or emotions. This indicates that variance in brain activity is not due to lack of cognitive ability or lack of motivation, one of the points Heyman offers in his book as a reason for why some people become addicted. This study actually contradicts one of Heyman’s points, which is that the addicted person can still regulate their behavior and emotion. The study indicates that, at least in some cases, people who are addicted cannot do so. You can read the full study here.

Other evidence supports the brain physiology changing as well. A study done in 2007 and published in the American Journal of Psychiatry (see reference below) illustrates that chronic cocaine use actually changes the reward pathways in the brain. Every time a drug is used, it releases “pleasure chemicals” that make the user feel that “high” they get from using. After a period of consistent use, the brain adapts to having the pleasure chemicals present, and will function normally in this way. However, when the users attempts to stop using the drug, stress chemicals are released, and this causes panic in the user, which makes them want to use again in order to feel “calm”. This process also causes withdrawal as once the brain has adapted to functioning on the drug, taking it away causes the brain to lose its ability to function normally.

To the extent that it seeks to move the disease/choice debate in a data-based direction, Gene Heyman’s book has the potential to help advance this longstanding discussion. Ultimately, most people with substance use disorders will benefit from both motivational and medical interventions, and so we need models and knowledge of both. Without having read the entire book, I want to be careful not to make any conclusions beyond that for risk of misrepresenting Heyman's arguments--if anyone has read it already (it came out in June), please leave comments letting us know what you thought.

Reference:

Koob, George & Kreek, Mary Jean (2007). Stress, dysregulation of drug reward pathways, and the transition to drug dependence. The American Journal of Psychiatry, 164 (8), 1149-59. Retrieved June 1, 2009, from Research Library Database. (Document ID: 1314241921).