Recent Internet Addiction Brain Studies Include Porn (2013)

Comments: Many studies have been published since this article was first written (January, 2013). All lend support to both internet addiction and porn addiction.


Brain research on Internet addiction points in only one direction 

Since we wrote Ominous News for Porn Users: Internet Addiction Atrophies Brains, which addressed recent online videogame addiction research, a tide of brand new research has been rolling in from around the world, revealing that a surprisingly large percentage of people in some age groups are addicted to Internet use itself.

The new research comprises two types of studies. One methodology uses brain scans of physical, addiction-related changes in addicts and control groups. The other uses surveys and addiction tests. (Sample test) Brain scientists also use such tests to divide subjects into test groups of addicts and control groups of non-addicts. (See the 300 Internet addiction brain studies. Read short summaries of Internet addiction studies, and ones that mention porn. Or see this collection of Internet and Videogame addiction studies).

In this post, we will be discussing research from both categories, but we’re primarily interested in the hard-science brain scans because they are less easy to manipulate with bias. Here are some FAQs about the new research:

What’s the percentage of Internet addicts according to the research?

Although the questionnaire studies use somewhat different terminology (“addiction” “problematic Internet use” “maladaptive Internet use”), rates range from 8 percent to as high as 21 percent in young people. Moreover, in a study that reported addiction rates by gender, a quarter of the male university students tested were diagnosed as addicts—as compared with less than ten percent of female students.

If there are no brain studies isolating Internet porn users, how can we know Internet porn addiction exists?

  • Porn/sex addiction? This page lists 39 neuroscience-based studies (MRI, fMRI, EEG, neuropsychological, hormonal). They provide strong support for the addiction model as their findings mirror the neurological findings reported in substance addiction studies.
  • The real experts’ opinions on porn/sex addiction? This list contains 16 recent literature reviews & commentaries by some of the top neuroscientists in the world. All support the addiction model.

Internet addiction researchers measure all Internet use, so pornography and social media are lumped together. One of the most recent studies, for example, described the Internet use of Chinese addicts:

Subjects used the internet almost every day, and spend more than 8 hours … every day in front of the monitor, mostly for chatting with cyber friends, playing online games, and watching online pornographies or adult movies. [Internet porn, by the way, is officially banned in China.]

Internet porn use has not been isolated in any of the new studies we have seen. (Who uses the Internet only for Internet porn?) But is it necessary to isolate Facebook addicts from Twitter addicts? Or World of Warcraft addicts from EverQuest addicts to determine that all such applications can become addictive for some users? No. Internet porn is simply one more, very popular, Internet pastime, and therefore potentially addictive.

Don’t let the fact that many use the Internet as a masturbation aid confuse you. It is the characteristics that make Internet porn different from sex—but very similar to videogaming or slot-machine gambling—which account for its ability to hook some users. This 2013 study noted the similarities:

“It should be pointed out that, as two of the key uses of the internet for a sizable number of internet users are to gain access to pornography and gambling and these latter activities are clearly subject to potentially-addictive states, it may be that any results relating to ‘internet addiction’ are actually manifestations of other forms of addiction (i.e. to pornography or gambling).”

These characteristics include novelty-at-a-click, effortless access, and constant violation of expectations via startling stimuli. All of these release the neurotransmitter dopamine in the reward circuitry. Overconsumption can therefore dysregulate dopamine response in some brains, thus tampering with mood, confidence and ability to respond to pleasure.

Still convinced Internet erotica is a harmless exception to Internet addiction? Sorry, but it has already been determined to be more likely to lead to compulsion than any other Internet activity.

In any case, the fundamental brain changes for all addictions—both behavioral and chemical—are so similar that addiction specialists now consider all addiction to be one disease rather than many different diseases. Whether someone is diagnosed with gambling, videogaming or Internet addiction, it indicates that a specific collection of anatomical and physiological abnormalities has occurred (with minor variations).

Indeed, the same molecular switch triggers addiction-related brain changes in all addicts. The master switch that triggers these changes is the protein DeltaFosB. Both chronic, high level consumption of natural rewards (sex, sugar, high-fat) and chronic administration of virtually any drug of abuse cause DeltaFosB to accumulate in the reward circuit, thus triggering a cascade of further brain changes.

It would be interesting, but redundant, to isolate particular types of Internet addiction in order to establish the reality of any one of them, including porn addiction.

What brain changes have researchers observed in Internet addicts?

Thirty years and thousands of studies on animal and human subjects have revealed a specific constellation of addiction-related brain changes. This is why scientists are confident that these brain changes differ from the brain’s normal daily activity.

For example, the Chinese study cited above, researchers concluded that,

IAD [Internet addiction] may cause serious damages to the brain, and the neuroimaging findings further illustrate IAD is associated with dysfunctions in the dopaminergic brain systems. Our findings also support the claim that IAD may share similar neurobiological abnormalities with other addictive disorders [such as substance abuse disorders and pathological gambling.]

Next we’ll consider the changes so far observable in human scans, with representative studies in the links next to brain alteration. (Note, this review of Internet Addiction brain studies was published after this article: Internet and Gaming Addiction: A Systematic Literature Review of Neuroimaging Studies)

  1. Desensitization. Refers to a general dialing down of one’s responsiveness to all pleasure…a baseline change. Leaves the addict less sensitive to pleasure, and “hungry” for dopamine-raising activities/substances of all kinds. Representative Internet addiction studies: Study 1, study 2.
  2. Sensitization. Hyper-reactivity to addiction-related cues.  Leads to hard-to-ignore cravings for one’s particular addiction. Study 1, study 2
  3. Hypofrontality. Frontal-lobe gray matter and functioning decrease. Reduces impulse control, decision-making, and the ability to foresee consequences. Study 1, study 2, study 3, study 4, study 5, study 6, study 7, study 8
  4. Abnormal White Matter. Gray matter is responsible processing information, whereas white matter comprises the communication pathways between different parts of the brain. Abnormalities of pathways between reward circuit structures and the frontal cortex are related to poor impulse control and reduced cognitive abilities. Study 1, study 2, study 3.

DeltaFosB is known to trigger most, if not all, of these addiction-related changes. They are not beneficial. (More on why in a future post.)

Are these the only brain changes?

No. Each of these broad-brush indicators reflect multiple subtler addiction-related cellular and chemical alterations—just as the scan of a cancer tumor wouldn’t show associated subtler cellular/chemical changes.

Most of the subtler changes can’t be assessed in human models due to the invasiveness of the technologies required. However, they have been identified in animal models. For example, to track desensitization, scans can measure D2 receptor changes in humans. Yet other key addiction markers, such as higher dynorphin and the accumulation of DeltaFosB, won’t show up in scans.

The point is that where there are macro changes visible in brain scans, there are also subtler, micro changes. The macro changes are the final dominos common to all addictions, so they are also evidence of the micro changes.

How do we know these brain changes aren’t due strictly to pre-existing pathologies?

Many experts have been taught that the only people who develop addiction are those with pre-existing disorders, such as OCD, depression, ADHD and so forth, so addiction is always a secondary disease, and presumably somewhat unavoidable. While brains do differ in their vulnerability to addiction (for example, adolescent brains are more vulnerable than adult brains), ASAM’s addiction specialists now consider addiction a primary disease. That is, it can develop even without the presence of an underlying disorder. And it causes its own brain changes apart from any other disorders.

Moreover, one has only to consider the rates of food addiction in the United States (79% of adults overweight and almost half of those obese) to see that one doesn’t need to be in a small, congenitally disordered minority to fall into addiction. This is especially true where extreme versions of natural rewards like food and sex are concerned. Junk food and Internet porn are both extreme versions of enticements that all of us evolved to pursue somewhat impulsively.

Moreover, two of the new studies (study 1, study 2) revealed that addiction-related brain changes were reversing themselves in former addicts. This wouldn’t happen if the brain changes were the product of fixed, pre-existing conditions. Similarly, the longer addicts are hooked, the more severe their addiction-related brain alterations:

The gray matter atrophy and white matter FA changes of some brain regions were significantly correlated with the duration of internet addiction.

Indeed, experts recently concluded that they,

cannot find a solid pathological predictor for Internet addiction disorder. Internet addiction disorder may bring some pathological problems to the addicts [such as depression, anxiety, hostility, interpersonal sensitivity, and psychoticism].

On what do you base your information in this post?

In addition to the many recent Internet addiction studies cited here, support for this piece comes from the materials published by the American Society of Addiction Medicine (ASAM), a group of eminent doctors and researchers who are addiction specialists. Here are some excerpts from the ASAM FAQs, which shed light on how experts in the field define addiction:

Qs: What’s different about this new definition? [and] Does ASAM really believe that food and sex are addicting?

“This new definition makes clear that addiction is not about drugs, it’s about brains. It is not the substances a person uses that make them an addict; it is not even the quantity or frequency of use. Addiction is about what happens in a person’s brain when they are exposed to rewarding substances or rewarding behaviors, and it is more about reward circuitry in the brain and related brain structures than it is about the external chemicals or behavior that “turn on” that reward circuitry….Food and sexual behaviors and gambling behaviors can be associated with the “pathological pursuit of rewards” described in this new definition of addiction.”

To summarize the current state of addiction neuroscience:

  • Addiction related behaviors and symptoms = a specific set of measurable brain alterations.
  • The brain changes found in all addictions include sensitization, desensitization, hypofrontality, and abnormal white matter. An Internet addiction is no exception, whether a user is viewing Internet porn, Facebook, www.reddit.com, or a combination Internet stimuli.
  • All addiction-related brain changes (both behavioral and chemical) are triggered by accumulation of DeltaFosB. There’s one molecular switch, whether drug, gambling, food, or Internet porn addiction is at work.
  • All brain research on Internet addiction done so far (ten studies as of this post) point in only one direction.

If you are noticing these unpleasant symptoms, you may have Internet addiction, and your Internet porn use could be part of the problem.

You may also find our related post Politics, Porn and Addiction Neuroscience of interest.

“Infographic” on Internet addiction


For well written lay articles on Internet addiction see –