Is there really such a disorder as "Internet addiction"? In my estimation, the short, honest answer is, "We don't know enough to say for sure." Part of the problem is the ambiguity in—and disagreement over—the terms "addicted" and "addiction." An even more serious problem is sorting out the role of "the Internet" (and other electronic media) from the role of underlying emotional problems or psychiatric disorders that may better explain the so-called addictive behavior.
The new and controversial manual of psychiatric disorders—the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-5—does not recognize any disorder called "Internet addiction." However, DSM-5 does describe "Internet gaming disorder" as a condition that requires "further study" before becoming an official diagnosis.
The DSM-5 is a bit evasive when it comes to defining the term "addiction." It notes that the term is in common usage, and typically applies to "more extreme" forms of "relapsing, compulsive drug taking." But the actual term "addiction" is not a part of the DSM-5's diagnostic criteria, owing to "its uncertain definition and potentially negative connotation."
For the most part, the DSM-5 does not buy into the concept of so-called "behavioral addictions"—"exercise addiction," "sex addiction" or "shopping addiction"—owing to the lack of credible evidence that these are bona fide mental disorders. The only exception is the DSM-5 category of gambling disorder, for which we have fairly good clinical, epidemiological and genetic evidence; for example, gambling problems are more frequent in identical twins than in fraternal twins, suggesting an inherited component.
All these qualms and complexities aside, there is little doubt that some people do spend enormous amounts of time and energy engaged in online activities—in some cases to the clear detriment of their work, family and social life. There is some evidence that, when deprived of online access, these persons may experience unpleasant withdrawal-like effects, such as anxiety or low mood. (These effects, however, are nowhere near as severe or life-threatening as withdrawal from, say, alcohol or barbiturates.) There are even anecdotal reports of people dying from blood clots or dehydration after "binging" on Internet video games for two or three days straight, without getting out of the chair.
There is no debate that these individuals have a serious behavioral problem that requires professional help. But is this true "addiction," akin to, say, addiction to opiate drugs? And if so, does it represent a specific "Internet addiction"? Or do these individuals have some underlying predisposition to excessive or compulsive activities in general—a tendency that, in the absence of the Internet, would pop up as a gambling problem, nicotine addiction or some other excessive activity that interfered with their ability to function?
We have evidence from various studies of brain activity that several different kinds of excessive or compulsive activities lead to similar changes in the dopamine-driven "reward system" of the brain. For example, Doug Hyun Han and colleagues, writing in Comparative Psychiatry, have shown that intense video gaming, substance dependence and pathologic gambling all activate similar regions of the brain. On the one hand, such findings might argue in favor of considering "Internet addiction" a bona fide, biologically based disorder. On the other hand, these brain studies might point to a single, underlying biological mechanism that simply emerges in different pathological forms, under different circumstances.
Furthermore, there is the problem of so-called comorbidity. Many individuals thought to have an "Internet addiction" also have a variety of concomitant or contributing psychiatric problems or disorders, such as schizophrenia, major depressive disorder or obsessive-compulsive disorder. It seems likely that, in many cases, such well-recognized conditions may better explain the person's abnormal Internet use than a new and discrete diagnosis called "Internet addiction." However, this view may change as we investigate familial disposition, genetic patterns, biological underpinnings and response to treatment among those diagnosed with Internet addiction. In short, we have much to learn about this diagnosis, and the proverbial jury is still out.