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Is There Really a Difference Between Drug Addiction and Drug Dependence?

Yes, and here’s why

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


It is no secret that misinformation about addiction is rampant in popular media. One particular area of misinformation concerns what language gets used when describing topics related to addiction.If you have ever found yourself reading or warily chiming into discussions on social media about addiction,you might quickly get sucked into a world of confusion as you observe all sorts of individuals—medical professionals, journalists, parents, people who use substances, people in recovery—incessantly argue over terminology such as “addiction,” “dependence,” “abuse,” “misuse,” “habit-forming,” “recreational use” or “medicinal use.”

In my experience as a clinical psychologist and, dare I facetiously say, a Twitter addict, the most important and commonly confused distinction is between “addiction” and “dependence.” And it is no wonder.

The scientific construct of addiction has a rich and evolving history. Even the people who dedicate their lives to researching addiction and who are responsible for the very medical texts that we use to diagnose addiction haven’t arrived at a clear consensus about which terms to use when.


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A Contentious History

One of the main medical texts used by mental health professionals to diagnose addiction is called the Diagnostic and Statistical Manual of Mental Disorders (DSM), which is currently in its fifth edition.In the 1980s a committee of experts met to revise what was, at the time, the DSM-III. And after much debate over whether to use the term “addiction” or “dependence,” the word “dependence” was chosen by a margin of a single vote, mainly because some of the committee members believed the word “addiction” was pejorative.As a consequence, the diagnostic category of “substance dependence” stayed with us through the DSM-IV, until it was dropped in 2013 in the DSM-5, along with the diagnostic category of “substance abuse.”

The solution in the DSM-5 was to combine the categories of “substance dependence” and “substance abuse” into one category called “substance use disorder,” under a chapter heading called “Substance-Related and Addictive Disorders.” The purposeful use of thephrase“addictivedisorders” in the naming of this chapter was primarily because of the addition of gambling disorder to the DSM. And here, too, committee members grappled over and disagreed on whether to introduce the term “addictive” into the DSM-5.

The Biggest Source of Confusion

If that history lesson sounds confusing, that’s because it is and there’s no way to simplify what happened. But the biggest source of confusion concerns the word “dependence.” Prior to the DSM-III, the term “dependence” simply meant physiological dependence, as indicated by tolerance and withdrawal symptoms. Unfortunately, the DSM-III committee expanded the definition of “substance dependence” to not only include physiological symptoms of tolerance and withdrawal but also other psychological and social symptoms, such as uncontrolled use and negative psychological and social consequences as a result of drug use.

Thus, the medical world was left with two very different definitions of dependence: one that signified physical dependence and one that signified a more complicated kind of biopsychosocial dependence, which, in reality, was used as a proxy to diagnose “addiction.”

How Do We Define Addiction and Dependence Today?

With the removal of the category “substance dependence” from the DSM-5, the definition of “dependence” should be clearer: Dependence means physical or physiological dependence, as indicated by tolerance and withdrawal symptoms. It is a state of neuroadaptation that can occur after repeated substance use, whereby continued substance use is needed to prevent withdrawal symptoms. Dependence does not equal addiction, though it can be one feature of addiction.

The term “addiction” is much more complicated, and there still remains considerable debate in the medical community about exactly how to define it—for example, whether it’s best conceptualized within a disease model, a learning model or somewhere in between.Medically and in practice, addiction is most often diagnosed using the DSM-5 category of “substance use disorder.” Unhelpfully, however, the DSM-5 does not explicitly and transparently mention this. In fact, the American Psychiatric Association, which developed the DSM, nonchalantly uses the terms “substance use disorder” and “addiction” interchangeably on its Web site.

In medical practice, to get a diagnosis of substance use disorder, a mental health professional must first conduct a careful diagnostic interview. The interviewer assesses whether there is a problematic pattern of substance use or behaviors causing a person distress and impairment in his or her functioning in a clinically significant way. In addition, a person needs to meet at least two of these 11 symptoms:

  • repeated use resulting in a failure to fulfill major role obligations

  • repeated use in hazardous situations

  • continued use despite social/interpersonal problems

  • cravings

  • tolerance

  • withdrawal

  • use for longer periods or in larger amounts than intended

  • persistent desire or unsuccessful attempts to control use

  • a great deal of time spent in activities related to use

  • reduced important social, occupational or recreational activities

  • continued use despite physical or psychological problems

Can Someone Be Dependent without Being Addicted?

Absolutely. Physiological dependence is common and can occur with many different kinds of substances, including those considered medications. In fact, it’s important for medical professionals to get this right and to differentiate between physiological dependence and the more complicated addiction construct because the diagnosis will help point to the best treatment option.

Can Someone Be Addicted without Being Dependent?

This is a much tougher debate, but the short is answer is yes. According to the DSM-5, it is possible to meet diagnostic criteria for a substance use disorder without having tolerance and withdrawal symptoms. That said, for many but not all substances, tolerance and withdrawal are often part of the package of substance use disorder symptoms. Also, in my experience, some professionals somewhat arbitrarily consider a “substance use disorder” an “addiction” only in cases of a “severe substance use disorder” diagnosis, as indicated by six or more of the 11 DSM-5 symptoms—which often includes tolerance and withdrawal.

Why Does it Matter?

My hope for this piece is to clarify rather than further confuse the distinction between “addiction” and “dependence,” something that is not only confusing among nonexperts but among medical professionals as well.

Even the Centers for Disease Control and Prevention is confused, as evidenced by the terminology page on its Web site, which states that for  “drug addiction,” the “preferred term is substance abuse disorder.” This is false. To reiterate, the DSM-5 dropped the categories of “substance dependence” and “substance abuse.”

While much of the confusion over this can be traced to DSM committees, I would caution against an oversimplified blame game. The topic itself is inherently complicated, situated in the context of an evolving medical and cultural milieu.

At the same time, the distinction between these two concepts—addiction and dependence—is not trivial. Medical professionals are ethically required to get the diagnosis right so that they can get the treatment right.

Jonathan N. Stea, Ph.D., R. Psych, is a registered and practicing clinical psychologist in Calgary, Alberta, Canada, and adjunct assistant professor at the University of Calgary. Clinically, he specializes in the assessment and treatment of concurrent addictive and psychiatric disorders. Follow him on Twitter @jonathanstea.

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