The key to addressing the addiction epidemic begins with science
Vivek Kumar, Ph.D.
Editor's note: This editorial was originally published Feb. 2, 2016 in the Portland Press Herald.
Maine is in the midst of an addiction epidemic, with a record number of hospitalizations and deaths from overdose. Lawmakers unanimously passed L.D. 1537 as a first measure to deal with this crisis. Surprisingly, much of the legislative and social debate in Maine about this issue is grounded in an outdated view of addiction, not in modern neuroscience.
Addiction has historically been seen as a problem of willpower, a voluntary intake of drugs by addicts who are personally responsible for their actions and should suffer the consequences. Neurobiology and medical communities now widely accept that addiction is a chronic health issue, much like diabetes or hypertension, that can be medically managed with long-term treatment and monitoring. Over the past two decades, neuroscience research has demonstrated that addiction falls along a spectrum of behavioral disorders with clear genetic, neurobiological and environmental influences.
To highlight this, let us compare the genetic, neurobiological and environmental factors of addiction with respect to two other chronic illnesses: diabetes and hypertension.
There are “hard wired” neural circuits in the brain reward system that, when perturbed, lead to a number of pathologies, including depression, anhedonia (the loss of interest in previously rewarding activities), impulsivity and compulsivity.
The initial use of and, ultimately, addiction to illicit drugs can be a method of coping with a neurobiological system that is broken. The recent obituary of Coleen Singer perfectly highlights many of the challenges that individuals with this neurobiological liability face. Much like a malfunctioning pancreas for diabetes, addiction has a clear biological basis.
The contribution of genetics to addiction is very similar to that of diabetes and hypertension. Twin studies show that the genetic contribution to addiction ranges from 20 percent to 80 percent, depending on the drug of abuse. Similar studies for diabetes have shown a range of 30 percent to 80 percent, and the genetic contribution to hypertension is 36 percent to 70 percent. Thus, there are clear and quantifiable genetic components to addiction, much like other chronic illnesses.
Carrying a genetic burden does not necessarily mean that a person will get the disease. Here, environment is key, but its influences are harder to quantify. There are cultural and social norms that are not under our control.
For instance, I grew up with and developed a preference for a diet that is high in fat, sugar and salt. This is part of my South Asian heritage. If not managed properly, this preference, coupled with genetics, can ultimately lead to diabetes and hypertension as an adult.
Similarly, certain cultural norms exist regarding the earlier use of addictive substances such as alcohol and nicotine. When combined with genetics, this can lead to dependence. Although most users of addictive substances never become addicts, the interaction of drug use with genetics and the environment of the individual plays a key role – and sometimes these interactions are not under our control.
Relapse rates among addicts and people with diabetes or hypertension are also similar. Roughly 40 percent to 60 percent of addicts will stay clean 12 months after entering treatment. Similarly, 30 percent to 70 percent of diabetes and hypertension patients will experience reoccurrence of symptoms within a year of treatment onset.
However, the key difference is how this is perceived. In the case of diabetes and hypertension, the fact that treatment suppressed symptoms is considered a success, even if the symptoms reoccur. But with addiction, the reoccurrence of symptoms is seen as a sign that the treatment has failed.
Finally, there is a massive discrepancy in access to treatment. Imagine if insulin treatment for diabetics were abruptly stopped because of a state mandate, if diabetics had to drive two hours to receive a shot of insulin, or if their treatment facility suddenly shut down. This is exactly what addicts are experiencing in Maine. Furthermore, many insurance companies cover acute detox and stabilization but provide limited or no long-term treatment options for this chronic condition.
Addiction is a chronic illness, with genetic, environmental and social aspects that are similar in scope to illnesses such as diabetes or hypertension. Why should one be treated as a social and moral failure while the other is a medical issue? As the neurobiology and medical communities make very clear, addiction is a chronic disease, and its treatment needs to mirror that of other chronic diseases.
Vivek Kumar, Ph.D., is an assistant professor at The Jackson Laboratory who uses mouse genetics as a platform to study behavior and behavioral abnormalities, including addiction, ADHD and depression. Follow him on Twitter at @vivekdna.