The campaign of recent years educating the public that addiction is a disease has had rather limited success at eliminating the stigma associated with addictions. In a previous essay, I addressed why many people continue to view addiction as a choice rather than a disease. However, even when people, including most physicians, accept addiction as a disease, the designation of “disease” remains confusing. Heroin addiction and alcohol addiction are not diagnostic terms – the proper terms come out of psychiatry: opioid use disorder and alcohol use disorder. Most people, including physicians, are not clear how or if “disease” differs from “disorder”. If addiction is a disease and not a disorder, is it a mental disease or a “real” disease like diabetes?

There is no fixed set of criteria that must be met for any condition to qualify for the label of “disease”. Attempts to define “disease” are fraught with difficulty and often resort to terms such as “disorder” of structure or function, or “illness”, which only serves to conflate “disease”, “disorder” and “illness”. Pragmatically, “disease” and “disorder” have different connotations – they “feel” very different.

Generally speaking, disorders occur along a continuum from normal to abnormal with no clear point where normal ends and abnormal begins. A heart rate of 120 beats per minute would be considered to be disordered at rest, but not when exercising. Similarly, anxiety is a disorder because it is normal response to stress but might be considered abnormal when it is inappropriately intense. by contrast, disease states are clearly different from normal states. For instance, outright cancer is never normal. Some diseases however, can develop from no disease, through mild and moderate disease, to severe disease. One such example might bee emphysema or chronic obstructive lung disease (COPD) where lung function gradually deteriorates over time. Another feature that separates diseases from disorders – diseases are often associated with identifiable defects, such as a blocked artery or a scarred liver. However, some diseases such as Alzheimer’s disease are difficult to diagnose on the basis of objective findings (blood tests or imaging), but are usually diagnosed by its manifestations.

I argue in this essay that it is important to be clear: addiction should not be considered a mental disorder, such as anxiety or depression. Rather, addiction should be considered a brain disease, like Alzheimer’s disease or Parkinson’s disease. Brain diseases are medical diseases rather than mental diseases/disorders/illnesses. Addiction should be considered a medical disease because it behaves very much like a typical chronic medical disease.

Let’s begin by comparing alcoholism directly with diabetes, which is universally accepted as a chronic medical disease. Both of these conditions are remarkably similar in so many ways. Both alcoholism and diabetes are known to have a genetic basis. Environments play large roles in the development of both these conditions. For instance, diabetes is twice as common in Mississippi than in Colorado, while someone raised in Las Vegas has a greater chance of becoming an alcoholic than someone growing up in the neighboring state of Utah, a dry, Mormon state. Lifestyle choices contribute greatly. Someone who shuns physical activity and relies overmuch on fast food would be at greater risk of diabetes; someone whose social interactions frequently include alcohol would be more likely to run into trouble with alcohol. Both conditions affect multiple organs in the body. Diabetes targets the kidneys, nerves and blood supply while alcohol can attack the pancreas, liver and the nerves. Most importantly, both conditions involve a loss of control of consumption – diabetics have trouble limiting food or sugar intake while alcoholics lose control of alcohol consumption. Given all these similarities, why should diabetes be considered a disease but not alcoholism?

We also find remarkable similarities when we compare addiction with any number of other chronic medical diseases. For this essay, I will compare addiction with four very different chronic medical diseases that have very little in common with one another: heart failure, Alzheimer’s dementia, kidney stones and osteoarthritis (“wear and tear” arthritis). These diseases differ vastly in their causes, the organs they affect, the types of people they afflict, etc. Yet, these diseases also share many similarities. In fact, each of these diseases shares as much with addiction as they do with each other.  

All these diseases involve genetic or other biological factors. Environmental factors are important while lifestyle choices play substantial roles. All of these conditions behave along similar patterns. They are all chronic but also experience periodic flare-ups (relapses in addiction). Many of these four diseases can worsen over time and can eventually prove fatal. These diseases are difficult to cure but the goal of treatment is to control rather than to cure.

The importance of considering addiction as medical disease rather than mental disorder lies in how we think about mental illness. The spectrum of anxiety or depression from normal to abnormal can unconsciously cause mental illness to be associated with weak-mindedness. The assumption is often made that mentally strong or tough people would be more resilient. Hence, people who suffer anxiety or depression are perceived as somehow mentally inferior and not to be trusted in positions of responsibility, leading to stigma.

Beyond reducing stigma, recognizing addiction as a disease should lead to profound differences in philosophy of treatment. My next essay will focus on what treating addiction as disease really means, by drawing parallels with the treatment of other diseases.