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Can any behavior be addictive? The answer is probably “yes,” depending on the person. Having said that, in our book, Why Can’t I Stop?, we selected the behaviors that we and others see as having the strongest relationship to substance addictions. Although the pathological use of alcohol or drugs has been historically accepted as addiction, neuroscience research has now set the stage for an expanded definition of addiction. The fifth edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5) officially recognized for the first time that behaviors could be regarded as forms of addiction. The DSM-5’s new chapter “Substance-Related and Addictive Disorders” includes gambling disorder, previously included with the “Impulse Control Disorders Not Elsewhere Classified.” The disorder was relocated because of evidence showing that gambling and substance addiction have consistently high rates of co-occurrence (meaning they tend to occur together in the same person more often than would be expected by chance alone), similar presentations of some symptoms, and genetic and biological overlap. Biological overlap means that gambling and drugs of abuse appear to activate the same brain reward system, with similar effects.
Other behaviors may have similar effects on the brain’s reward system, but they were either considered and rejected for inclusion in the DSM-5 category of “Substance-Related and Addictive Disorders” (for example, Internet addiction and compulsive sexual behavior), were not even part of the debate (for example, food addiction, kleptomania, and compulsive buying), or were under consideration for a different grouping (the grooming disorders of trichotillomania [hair-pulling disorder] and excoriation [skin-picking] disorder were included as part of the “Obsessive Compulsive and Related Disorders” category).
Although mental health research is ongoing to understand the cause of these disorders, we still rely heavily on clinical symptoms to group disorders rather than having a full understanding of the problems in the brain itself. For example, some think compulsive sexual behavior should be grouped with other sexual problems instead of with addictions. Is it possible, however, that compulsive sexual behavior has similarities to substance addictions? If a small percentage of people with compulsive sexual behavior have brains similar to those of people with other sexual problems, and a large percentage have more in common biologically with people who have drug addiction, should compulsive sexual behavior be considered a sexual disorder or an addiction?
Even if we accept that certain behaviors (such as gambling) share some clinical and probably biological similarities to substance addiction, and even if we accept that grouping disorders is far from ideal, we are still left with deciding which disorders should be considered behavioral addictions. Decisions on which behaviors to include in our book are rooted in two important points: first, based on the existing research, we include behavioral disorders that we believe have the strongest similarities to substance use disorders; and second, we are aware that not everyone with a particular disorder is similar to someone with a substance use disorder. Although we talk broadly about these disorders, we must stress that there is substantial variability within each disorder. That is, someone with gambling disorder may appear similar to someone with a substance addiction, while someone else with gambling disorder does not.
Jon E. Grant, JD, MD, MPH, Brian L. Odlaug, PhD, MPH, and Samuel R. Chamberlain, MD, PhD are the co-authors of "Why Can't I Stop?: Reclaiming Your Life from a Behavioral Addiction"
