Over the holidays, it’s an increasingly common encounter with addicted individuals who frequently congregate outside urban liquor stores. As an internal medicine physician who works in Vancouver’s busiest inner city hospital, I often recognize these lost souls from past encounters in the emergency room. Sometimes I spare a dollar or two. But with more than a decade of research into the study of addiction, I know it can’t be treated with pocket change.
Many view those who have succumbed to alcohol or drug addiction as suffering from a moral weakness that can only be rectified through law enforcement. However, recent advances in neurobiology are directly challenging society’s long-held views regarding the causes and solutions to drug and alcohol addiction.
Perhaps most remarkable is that researchers now attribute approximately 50 per cent of vulnerability to addiction to genetic factors. The interaction between genes and environmental “exposures” explains why alcohol abuse tends to run in families and why negative life experiences can predispose to severe addiction.
Just a few weeks ago, a pair of new studies released by researchers at the University of British Columbia demonstrated how childhood sexual abuse and homelessness contribute to increased risk of intravenous drug use experimentation among at-risk youth.
At the centre of the interaction between genes and the environment is a part of the brain neurologists refer to as the dopaminergic system. It stimulates cravings for and rewards us with feelings of enjoyment when we obtain things such as food and sex, both of which increase the likelihood that we will pass on our genes to future generations.
In genetically susceptible individuals, this system is wired in a way that exposure to drugs or alcohol can hijack the natural reward system and severely compromise areas of the brain responsible for impulse control. This results in the extremely compulsive behaviours that characterize addiction.
We are not, however, simply slaves to our genetic makeup. Advanced neuroimaging techniques have recently uncovered the remarkable plasticity of the brain’s impulse control system. North Carolina researchers have shown how rhesus monkeys will quickly develop markedly decreased levels of the neurotransmitter dopamine when kept caged in stressful, isolated environments, and will self-administer cocaine to boost dopamine levels. The brains of these same animals return to normal, and cocaine use is markedly reduced, when the monkeys are placed in a positive social environment.
While it is not known if putting humans in cages produces similar brain changes, high rates of incarceration do have proven negative societal effects.
In the U.S., where one-eighth of young adults report that their biological father has been imprisoned, often for a substance use-related offence, research found paternal incarceration strongly predicted subsequent adolescent drug use. Society’s punitive approach to addiction has, in effect, created a taxpayer-funded system of promoting intergenerational drug use.
Given how research has fuelled recent advancements in addiction medicine, this poses the question: Why is addiction treatment so sorely underfunded in Canada?
A recent study by Princeton University scientists may provide a clue. Using a modern neuroimaging technique called functional magnetic resonance imaging, the researchers localized the parts of the brain that were activated when participants were shown pictures of individuals from different social strata — such as middle-class Americans, Olympic athletes and drug addicts.
When undergraduate students were shown images of addicted individuals, only the area of the brain consistent with experiencing disgust was activated. Researchers concluded addicts were being “perceived as less than human.”
This is society’s brain on drugs. Billions of tax dollars fund a barrage of anti-drug advertising that does not reduce drug use, but does dehumanize the addicted.
Meanwhile, addiction treatment goes grossly under-funded. Prisons are built. Addicts are patched up and discharged back to the street. Spare change is dropped in cups by passersby.
Evan Wood, MD, PhD, is a professor of medicine at the University of British Columbia, where he holds the university’s Canada Research Chair in inner city medicine.