Ominous News for Porn Users: Internet Addiction Atrophies Brains

"Game Over" button

Here’s some headline news for anyone who has been trained that Internet porn use is harmless: Physical evidence of addiction processes is showing up in the brains of avid Internet video-gamers. What’s more, use of online erotica has greater potential for becoming compulsive than online gaming according to Dutch researchers.

According to NIDA head Nora Volkow, MD, and her team these three physical changes define addiction: desensitization (numbing of the brain’s pleasure response), sensitization, and hypofrontality. These same brain changes (which are now showing up in Internet addicts) also show up in pathological gamblers and drug abusers.

For example, cocaine use floods the brain’s reward circuitry with dopamine. Nerve cells respond, more or less quickly, by decreasing their responsiveness to dopamine. As a result, some users feel “off” (desensitization). They crave more intense stimulation (tolerance), and tend to neglect interests, stimuli, and behaviors that were once important to them.

At the same time, because their brains have recorded that cocaine use feels good, they grow hypersensitive to anything they associate with cocaine. White powder, the word “snow,” the neighborhood where they smoked, or friends with whom they used will all trigger spurts of high dopamine in the reward circuitry, driving them to use (sensitization). Also, ΔFosB, a protein that helps preserve intense memories and promotes relapse, accumulates in key brain regions. Incidentally, ΔFosB also rises with sexual activity.

If heavy cocaine use continues, the desensitization of the reward circuitry decreases corresponding activity in the frontal lobes of their brains. Now, the users’ abilities to control impulses and make sound choices weaken, and their frontal cortex may atrophy (hypofrontality). Taken together, decreased pleasure response, marked cravings to use, and compromised impulse control fuel the vicious cycle of addiction.

Behavioral addictions

The study of non-drug addictions is still quite new. Yet already experts have uncovered decisive physical evidence that today’s extreme versions of natural rewards can change the brain in ways that drugs do. “Natural rewards” are activities/substances that entice us because they enhanced our ancestors’ survival, or the survival of their genes.

Moreover, it’s not just a tiny minority with pre-existing disorders who are at risk. Normal, healthy brains can also change. Said a healthy 37-year old, “When I first watched porn online at age 35, I felt like I was going to have an orgasm without an erection. That’s how powerful an effect the it had on me.”

So far, here’s the research scorecard. (Dates indicate when brain-scan research turned up evidence of the last of the three key addiction-related brain changes.)

  • Pathological gambling – studied for 10 years, and added to the upcoming DSM-5 as an addiction (2010)
  • Food addiction – (2010)
  • Internet video-gaming addiction – (2011)
  • Internet porn addiction – still not studied via brain scans

Incidentally, the reason the Internet addiction studies address addiction to gaming, not porn, is that they were done in countries that block access to porn sites—and have for years (China, 2006 and Korea, 2007). Unlike other countries, they don’t have a lot of heavy porn users.

Here are studies showing the three critical, physical changes in the brains of Internet addicts (two just released in June, 2011):

A reduction of striatal D2 dopamine receptors is the main marker for desensitization of the reward circuitry, a hallmark of all addictions. In this study PET scans of men with and without Internet addiction were compared.

“An increasing amount of research has suggested that Internet addiction is associated with abnormalities in the dopaminergic brain system… [In this study] individuals with Internet addiction showed reduced levels of dopamine D2 receptor availability.”

In this study, college students played Internet video games for 6 weeks. Measures were done before and after. Those subjects with the highest cravings also had the most changes in their brains that indicate early addiction process. The control group, which played a less stimulating game, had no such brain changes.

These changes in frontal-lobe activity with extended video-game play may be similar to those observed during the early stages of addiction.”

In this study, researchers found a 10-20% reduction in frontal cortex gray matter in adolescents with Internet addiction. Research on other addictions has already established that decreases in frontal-lobe gray matter and functioning reduce both impulse control and the ability to foresee consequences.

“The presence of relatively immature cognitive control, makes [adolescence] a time of vulnerability and adjustment, and may lead to a higher incidence of affective disorders and addiction among adolescents. As one of the common mental health problems amongst Chinese adolescents, internet addiction disorder (IAD) is currently becoming more and more serious. … The incidence rate of internet addiction among Chinese urban youths is about 14%. … These results demonstrated that as internet addiction persisted, brain atrophy … was more serious.” (Also see this earlier Chinese study.) 

Online porn and video gaming stimulate the brain in comparable ways

Compare these two quotations. Which is about porn addiction and which is about gaming addiction?

We don’t have sex anymore. We don’t go on date nights or anything together. I feel so guilty because I just can’t take it anymore. Ever since 2 weeks into our marriage I was threatening to divorce him.

Three of my friends did realize they had a problem, but 2 of them said they’ve made attempts to quit, and they literally think there’s nothing they can do about it. *

The characteristics that make Internet porn and video gaming so popular are the same characteristics that give both the power to dysregulate dopamine in some brains. Novelty and ‘stimuli that violate expectations‘ both release dopamine, sending the brain the message that the activity is more valuable than it is. Successful video games deliver a rapid-fire of both novelty and surprise. Each new generation of games exceeds the last in these respects.

Today’s porn also delivers both, and constantly ratchets them up. There’s unending novelty and something more startling always beckoning just beyond the next click. There’s also the dopamine released by the “hunt” for the perfect shot. Novelty, shock and hunting absorb the user’s attention because they raise dopamine levels. Intense focus allows users to override their natural satiety mechanisms and, often, to rewire their brains in ways that take a lot of effort to undo. Addiction is “pathological learning.”

Online gamers are sometimes called “adrenaline junkies.” However, adrenaline (which is released in the adrenal glands) appears to have little effect on addiction processes. Dopamine, not adrenaline, is at the heart of all addictions. Fear and anxiety can enhance addiction processes due to neurochemicals released in the brain (such as norepinephrine), but they don’t cause those processes.

Sexual cues can be more compelling than gaming activities

Mock warfare and risky quests were no doubt high priorities for our ancestors. That’s why we find play rewarding enough to get hooked. Yet reproduction is our genes’ top priority. Like food, sex is essential to genetic success.

In terms of effects on the brain, Internet porn use combines elements of consuming highly palatable food and video gaming’s constant stimulation. Like junk food, Internet erotica is a hyperstimulating version of something we evolved to value highly. Today’s erotica is also delivered via a rapid-fire, mesmerizing medium, very similar to online video games. A double whammy in terms of addictiveness.

It’s worth considering what brain researchers have learned about food. When rats had unlimited access to cafeteria food, nearly all of them showed a rapid drop in D2 (dopamine) receptors (numbed pleasure response), and then binged to obesity. The D2-receptor drop apparently motivates mammals to grab as much as possible while the getting is good—whether high-calorie foods or a willing harem.

Keep in mind that unlimited cafeteria-type food stimulation was not the norm during our evolution, until recently. That’s why unlimited access to junk food is risky to rats and humans. Clicking effortlessly to hundreds of hot, novel mates is also an evolutionary anomaly, and 9 out of 10 of college-age men were already using Internet porn three years ago. Risky, given its inherent addictiveness. Also, reversible. When heavy users give up porn, they report increased pleasure from all aspects of life (often after a miserable withdrawal).

Back to food. In recent years, brain researchers have also turned up evidence of all three key addiction processes in the brains of overeaters:

  • Numbed pleasure response: A 2010 study showed that overeating blunts the reward circuitry, increasing the risk for future weight gain. After 6 months, the brains of those who had eaten more “pleasurable” foods (i.e., more fattening) showed less response to pleasure than the others.
  • Sensitization: A 2011 study found that those who score high on a food addiction test (brain activation in response to pictures of food) show brain responses similar to drug addicts’ responses to drugs.
  • Hypofrontality: A 2006 study revealed that obese individuals have brain abnormalities in areas associated with taste, self-control, and reward—including a reduction of gray matter in the frontal lobes (atrophy). It’s likely that overeating causes these changes, as the study mentioned above confirmed brains changes from overeating.

If overstimulation via highly palatable food can cause brain changes in so many humans (30% of Americans are obese, and only about 10% due to metabolic abnormalities according to neuroscientist David Linden), how is it possible that over-stimulation via highly erotic online sexual activity could not change brains? Internet porn use/cybersex is surely no less stimulating than tempting food.

Is history repeating itself?

History is full of examples of “common knowledge” that turned out to be erroneous upon investigation. Consider margarine. Everyone “knew” it was better for you than butter. Experts were so confident of this “fact,” that they didn’t even test it for years, and regularly advised people to substitute margarine for butter.

Finally, experts did test the healthfulness of margarine. It turns out that trans-fatty acids (found in margarine) are among the most dangerous fats. They are far worse for humans than butter.

Critics may claim that it is “unscientific” to suggest that Internet porn can cause addiction processes in the brain just because Internet addiction clearly does. Actually, it’s unscientific to suggest the reverse. All addictions, including behavioral ones (gambling, food, video games) show hypofrontality (atrophy and lack of impulse control). Frankly, what critics now need to supply is solid, scientific evidence showing that Internet porn addiction is an exception to the rule. To suggest there’s still major doubt about its addictiveness is most unscientific, as it presumes there must be some other brain circuitry for porn use that has yet to be discovered.

Sex is healthy, but the assumption that Internet porn use is safe is increasingly tenuous.


* The first remarks are about gaming addiction, the second about porn addiction.

22 Responses to Ominous News for Porn Users: Internet Addiction Atrophies Brains

  1. genotopia July 1, 2011 at 2:41 pm #

    Your text directly contradicts your headline. You say yourself that it’s not studied, but your headline makes a claim anyway.

    Headline: “Internet Addiction Atrophies Brains”
    Handwaving inference: “So, how can Internet porn use not trigger such brain changes?”
    Admission: “Internet porn addiction – still not studied via brain scans”

    That’s not science; it’s insinuation.

  2. marnia July 1, 2011 at 3:00 pm #

    Our headline doesn’t make the claim you suggest.

    Further, are you saying that evidence that Internet addiction changes brains is *irrelevant* to excessive users of Internet porn? On what possible theory? All addictions involve the mesolimbic dopamine pathway, and the same three brain alterations: desensitization, sensitization and hypofrontality.

    Or, are you saying there’s a separate, undiscovered brain pathway/mechanism for Internet porn addiction? Tell us about it.

  3. John July 1, 2011 at 5:51 pm #

    What if I am addicted to my wife? Wives are women too, and if the article is right, she has probably destroyed my mind substantially by now. Is there any hope for me?

  4. Gary Wilson July 1, 2011 at 6:59 pm #

    To John: Perhaps your wife has destroyed your mind, but she only counts as a single genetic opportunity.

    Ever hear of the Coolidge effect?
    When you drop a male rat into a cage with a receptive female rat, first you see a frenzy of copulation. Then, progressively, the male tires of that particular female. Even if she wants more, he has had enough. However, replace the original female with a fresh one, and the male immediately revives and gallantly struggles to fertilize her. You can repeat this process with fresh females until he nearly dies of exhaustion. The rat’s reward circuitry is squirting less and less dopamine with respect to the current female, but produces a big dopamine surge for a new female.

    The Coolidge effect is one quality that drives Internet porn use – the constant search for novel “mating” opportunities. For many guys a single steady partner can’t juice the reward circuitry the same way an endless stream of novel partners and genres can. Each new scene is a new spike of dopamine.

    Dopamine not only responds to novelty, it also spikes with each click as the user searches for the perfect scene. Seeking and searching keeps dopamine levels elevated. In addition, dopamine rises with any scene or person that “violates our expectations”. In a love-making session with your wife, does she violate your expectations a few hundred times. It can certainly happen with Internet porn.

    From our post above you can see that Internet use, without porn, can cause addiction. What do you think can happen when all the dopamine goosing qualities of porn are mixed with high speed connections, multiple screens, surround sound? Go back to the original question – how can junk food, gambling and video games cause physical changes that mimic drug addiction, and Internet porn not?

    With all addictions in mind, ponder the qualities of Internet porn and how they affect the dopamine system in unique ways:
    1. Unlike eating or drugs, there’s no inherent limit to Internet porn consumption. One can keep dopamine surging for hours on end. Escalation of use is always possible.

    2. As stated, Internet porn affords extreme novelty (more brain-goosing dopamine at each click). This is what sets Internet porn apart from renting a video. Dopamine soars for novelty, anticipation, and the “hunt” for the next image or scene.

    3. The brain’s natural satiation mechanisms are not activated, unless one climaxes—which may not be for hours. Even then, today’s user often clicks to something more shocking to override the post-orgasm drop in dopamine and become aroused again.

    4. Unlike food or addictive drugs, Internet porn doesn’t eventually activate the brain’s natural aversion system. Who can’t bear to look at another erotic image? Reproduction is our genes’ top priority after all.

    As one guy said, “70s and 80s porn was much different than the fast food stuff of today. At least back then you had to rent a tape or buy one. You couldn’t just sit down and watch a zillion nude women at a click.”

  5. John July 1, 2011 at 7:57 pm #

    Gary, the addiction to my wife is as strong as any drug to a drug user. She is constantly presenting new ways to keep me addicted, so I’m pretty sure that she already understood the Coolidge effect and has been purposely using it against me to keep me addicted. This article has been a real eye opener for me. I think I will need to find a rehab center so they can help me leave my wife without my becoming too depressed, before I am hopelessly brain damaged by the excessive dopamine rush she gives me.

  6. Gary Wilson July 1, 2011 at 8:05 pm #

    Bonding (love) is considered the original evolutionary “addiction”. Romantic (honeymoon) love contains many features similar to addiction. Obsession, anxiety, sensitized pathways for the beloved, withdrawal symptoms if your break up, and of course, dopamine and the reward circuitry. However, it doesn’t appear to have desensitization or hypofrontality.
    Here’s a research article suggesting as much:
    Is social attachment an addictive disorder?
    Thomas R. Insel*
    Center for Behavioral Neuroscience, Emory University, Altanta, GA, USA
    Physiol Behav. 2003 Aug;79(3):351-7

  7. Gary Wilson July 1, 2011 at 8:09 pm #

    This study arrived a few days ago. The collection methods involved face-to-face settings. Problematic Internet use for adolescents was 18%, for adults it was 11%. The adolescent group was only 44.5% males. Considering the primary users of Internet porn and video games are males, one has to wonder how much higher the percentage would be in an all-male group.

    Confirmation of the Three Factor Model of Problematic Internet Use on Off Line Adolescent and Adult Samples.
    Koronczai B, Urbán R, Kökönyei G, Paksi B, Papp K, Kun B, Arnold P, Kállai J, Demetrovics Z.

    Source
    1 Institutional Group on Addiction Research, Eötvös Loránd University , Budapest, Hungary .

    As the Internet became widely used, problems associated with its excessive use became increasingly apparent. Although for the assessment of these problems several models and related questionnaires have been elaborated, there has been little effort made to confirm them. The aim of the present study was to test the three-factor model of the previously created Problematic Internet Use Questionnaire (PIUQ) by data collection methods formerly not applied (off-line group and face-to-face settings), on the one hand, and by testing on different age groups (adolescent and adult representative samples), on the other hand. Data were collected from 438 high-school students (44.5 percent boys; mean age: 16.0 years; standard deviation=0.7 years) and also from 963 adults (49.9 percent males; mean age: 33.6 years; standard deviation=11.8 years).

    We applied confirmatory factor analysis to confirm the measurement model of problematic Internet use. The results of the analyses carried out inevitably support the original three-factor model over the possible one-factor solution. Using latent profile analysis, we identified 11 percent of adults and 18 percent of adolescent users characterized by problematic use. Based on exploratory factor analysis, we also suggest a short form of the PIUQ consisting of nine items. Both the original 18-item version of PIUQ and its short 9-item form have satisfactory reliability and validity characteristics, and thus, they are suitable for the assessment of problematic Internet use in future studies.

  8. Ameriphysics July 1, 2011 at 11:13 pm #

    Well, we know what is right from wrong now and we need to do what is just right enough for our bodyt. Nothing more nothing less. Thanks Marnia for posting this very informative blog!

  9. santorini July 2, 2011 at 11:24 pm #

    Great post! I have a question for the Doctors: The last year, when Im writing something I curiously swap the order of the letters of some words. What could be the cause?
    example:

    “It’s grae…” then, I realize the error…. and fix it..”It’s great”. (I do it unconsciously)

    I’m a regular Internet user. Thanks.

  10. Fred July 3, 2011 at 9:09 pm #

    I could feel my brain getting smaller lately!

  11. Jon Samuelson July 4, 2011 at 4:42 am #

    I really enjoy this website, but it IS extremely disingenuous to use the headline “Ominous news for porn users: internet addiction atrophies brains”, then cite a study that does not make a direct connection between the use of internet pornography and brain atrophy, and finally claim that your headline is NOT insinuating such a connection. Inferences are part of scientific progress, and the inferences made in this article seem legitimate, but why is pornography singled out by the author of this post? Why not Facebook, or Twitter, or any number of pathological activities people display on the internet? I can absolutely see where the author is coming from, but to single out one addictive thing that is NOT related to the cited research and infer similarity, while ignoring many others, screams of an agenda.

  12. marnia July 4, 2011 at 8:56 am #

    @Jon “Disingenuous?” How are studies showing brain changes from Internet addiction not ominous news for heavy Internet porn users who say they can’t stop watching? The most recent study, which my husband (Gary Wilson) added below the original post, doesn’t even specify that it was examining gaming. It could have included porn use for all we know. And it showed that 18% of adolescents are suffering from problematic Internet use. (The sample was more than half female, so just imagine what the percentage would be in an all-male sample.)

    You also appear to be ignoring the Dutch study we linked to at the beginning of the article, which found that porn / cybersex has a greater risk for creating Internet compulsion than gaming. Ergo…any research on the addictiveness of the Internet is ominous news for heavy Internet porn users. There’s nothing deceptive about the headline.

    The point so many are determined to miss is that it’s the delivery of stimulation via the Internet that makes excessive use so risky in terms of addiction processes…whether one is looking at sex or shooting. Please read the two posts by “Gary Wilson,” above if you’d like more details.

    The writing is on the wall, and it’s reckless to keep insisting there’s no evidence of the addictiveness of Internet porn. Yes, there will be more evidence in the future as brain scans are done on actual porn users. But already it would be negligent for a professional to insist porn use is always harmless. All addictions come down to dysregulation of the same mechanisms in the brain. Internet porn cannot be fundamentally different.

  13. John July 4, 2011 at 7:37 pm #

    You have not shown whether the brain reduction occurred before or after introduction of video games. I have full access to video games, the latest of them all, and I don’t play them, or want to play them. I feel no desire to be violent in any manner. Is this due to my brain being larger, or some chemical imbalance that makes me unlike other human beings that are prone to playing video games?

    If I don’t play video games, is my brain getting larger rather than shrinking?

    How much per year?

  14. John July 4, 2011 at 7:52 pm #

    It is very likely that brain atrophy is caused by lack of sleep, rather than dopamine itself. Tell kids to shut off the games and go to bed.

    If you are going to continue deleting my posts, please delete them all. It’s not science if you are filtering discussion to only show one side.

  15. John July 4, 2011 at 8:06 pm #

    Why does a man go to sleep after sex?

    So his brain won’t atrophy.

  16. John July 4, 2011 at 9:21 pm #

    From http://www.fi.edu/learn/brain/sleep.html

    ‘Previous work by Dr. Van Cauter, a professor of medicine at the University of Chicago, found that “metabolic and endocrine changes resulting from a significant sleep debt mimic many of the hallmarks of aging. We suspect that chronic sleep loss may not only hasten the onset but could also increase the severity of age-related ailments such as diabetes, hypertension, obesity, and memory loss .”‘

    Further down that page:

    ‘A Northwestern University study of 500 preschoolers found that those who slept less than 10 hours in a 24-hour period (including daytime naps) were 25% more likely to misbehave. They were consistently at greatest risk for “acting out” behavioral problems, such as aggression and oppositional or noncompliant behavior.’

    Here we have some positive feedback active, re-enforcing them to keep playing the agressive video games day and night, losing sleep, which keeps them agressive and wanting to play the video games. Their brain then wastes away over a long period of time unless you can get them to shut the games off and go to sleep.

    It looks like a pattern to me: addicts and lack of sleep.

  17. Jon Samuelson July 5, 2011 at 1:56 am #

    I am not, in any way whatsoever, denying that internet pornography is addictive. Nor that it is MORE addictive than many activities one can partake in on the internet. My point is that the studies cited do not make a connection between addiction to internet pornography and brain atrophy. One study makes a connection between addiction to online gaming and brain atrophy. And a second study finds that online pornography appears to be more addictive than online gaming. You then make the inference that addiction to online pornography is as bad or worse, in terms of likely brain atrophy, than online gaming. Honestly, you’re probably right, but it is an inference. It’s not a fact, it’s not really science. The logical leaps of science can be, and often are, based on inference, but they must be tested in order to be validated. And, considering that so many of your posts involve the potential societal ills of pornography, and oversexualization in general, your inference in this case (at the expense of many other addictive behaviors) suggests that you have an agenda against the social taboo of pornography. Which is okay, lots of scientists have an agenda, climate scientists, environmental scientists, social scientists, economists, oncologists, but having an agenda shouldn’t preclude one from proving causal relationships with more than inference.

  18. marnia July 5, 2011 at 9:45 am #

    *chuckle* Jon, it is you who is inferring that I have an agenda. And you’re inferring it’s a moral one based on taboos. You couldn’t be more wrong.

    Through a search engine fluke (because we happened to have articles both about sex and the brain science of addiction on our site), hoards of heavy porn users began showing up in the forum of one of our websites 5 years ago…with all kinds of extreme symptoms. Our site is not religious and didn’t even mention porn.

    Most of our visitors had been using Internet porn for years, quite contentedly…until highspeed showed up and they hit the wall with mysterious symptoms they weren’t *sure* were from their porn use. Everything from erectile dysfunction, escalation to material they found disturbing, uncharacteristic social anxiety and brain fog to OCD symptoms.
    http://yourbrainonporn.com/what-are-the-symptoms-of-excessive-porn-use

    Some worked out that the best way to solve their problems was to “reboot,” that is restore the reward circuitry of the brain to normal sensitivity by giving their brain a couple month’s rest from extreme stimulation (porn/masturbation etc.). Many suffered extreme withdrawal symptoms. Self-reports: http://yourbrainonporn.com/what-does-withdrawal-from-porn-look-like

    The recovery results have been remarkable, however. Self-reports: http://yourbrainonporn.com/what-benefits-do-people-see-as-they-reboot Many report radical improvements that go way beyond their expectations: normal erections/sex – sometimes for the first time in their lives, increases in confidence and charisma, improvements in concentration and productivity, finding normal women increasingly attractive. Amazing. And all because they weren’t willing to sit around and wait for people like you to tell them what is or isn’t “scientific.”

    In effect, they conducted a scientific experiment…with a lot more objectivity than either “side” of today’s porn debate. They don’t care to promulgate the results, for obvious reasons. But their experience has made it clear to us that someone needs to share their findings, as well as the scientific evidence that likely accounts for their remarkable recoveries. We finally put together http://www.yourbrainonporn.com to collect as much as possible of both.

    To say our post is “unscientific” because it points out that today’s Internet porn users should be deeply concerned about the results of today’s Internet addiction research is absurd. Would you oblige porn users to sit in the dark like mushrooms until the matter is settled to your satisfaction (and the satisfaction of those with an agenda of declaring porn harmless despite all evidence)? Most of today’s experts, remember, were trained that porn is harmless (which it probably WAS, before highspeed Internet zapped people’s brains with constant novelty, searching and escalation). They don’t know a thing about addiction science, or why Internet porn is different. This leaves those suffering in a very precarious position.

    Your suggestion that we shouldn’t point out the relevance of Internet addiction research is like saying it’s unscientific to report all the bits of evidence pointing to the roundness of the earth until someone actually circumnavigates the globe. Unbelievable.

    Frankly, it’s unscientific to ignore all the scientific research that’s piling up about behavioral addictions and Internet use itself. My husband, who writes these posts with me, has taught physiology for years, and has a passion for neuroscience in particular, but I was trained as a lawyer. I can tell you that, based on the evidence that is already out there about behavioral addictions and Internet risks, any doctor or other expert who opines that heavy use of Internet porn is harmless is risking a malpractice suit. That’s how strong the *scientific* evidence already is. And yes, it will get stronger, when the right brain scans are done…someday.

    Many people do not want to see the truth, and therefore resort to Fox News style spin and silly labels like “unscientific,” but it doesn’t change the reality of the scientific evidence one bit. As a culture we can feign ignorance of the science of addiction and “pretend” that somehow Internet porn is vastly different from other Internet addictions, but it’s increasingly irresponsible to do so.

    As to the issue of hypofrontality (atrophy and lack of impulse control), *all* addictions, including behavioral ones (gambling, food, video games) show hypofrontality. So how can Internet porn addiction be an exception to the rule? Remember, NIDA head Volkow says Internet porn belongs in the list of behavioral addictions, and she has done many, many studies on addicts brains.

    It is actually more scientific to assume that Internet porn addiction *does* risk brain atrophy until science proves otherwise than the reverse. To suggest there’s still major doubt is most unscientific, as it assumes there must be some other brain circuitry for porn use that has yet to be discovered.

    Excuse the fieriness of this response, but having seen the unnecessary misery caused by the unscientific stance you espouse makes me a bit impatient. When those trapped understand the brain science of addiction, they can steer for the results they want. Let’s get the behavioral addiction information out there, and let users make their own experiments, since the scientists appear to be hamstrung by all the name-calling.

  19. Derreck July 7, 2011 at 3:07 pm #

    @Marnia

    Why can’t you answer a post in a succinct way.

    Jon made great points which you evade along with creating strawmen.

  20. flynnmd July 9, 2011 at 1:33 pm #

    Dunno you guys. The posts and back-up comments sure seem crystal-clear to me. It’s like the discussion I had with David Agus at TEDMED, who thought I was nuts to promote Vitamin D (or replacement testosterone) because he wasn’t satisfied with the current studies showing beneficial effects and wanted (something more? something different? something he researched?).
    And there’s no problem with crowd-sourcing as a way to collect data. It may not be as rigorously stratified but you’ll get a N many, many times larger than any clinical protocol. Or would you rather rely on findings sponsored by the (fill-in) industry?

  21. Louis Krodel July 19, 2011 at 3:03 pm #

    Actually there is a lot of brain studies using the MRIr regarding sexual responses to pornography on the internet and for women regarding the use of romantic(slash)novels. There is no evidence for “sex addiction”. I would note two problems of many: 1) sexual desire is a function of testosterone and testosterone levels varies widely in men and women; 2) medicine, psychiatry and psychology are notorious for inventing mental diseases; remember stomach ulcers were caused by anger/stress – now we know it is caused by a bacterium and both masturbation and homosexuality were diagnosable mental disorders. I recommend the following books: A Billion Wicked Thoughts: What the Worlds Largest Experiment Reveals about Human desire by Ogi Ogas, Sal Gaddam; “The Evolution of Desire by David M. Buss and “The Compass of Pleasure: How our brains make fatty Foods, Orgasm,Exercise,Marijuana, Generosity, Vodka, Learning and Gambling Feel so Good” by David J Linden

    • Wilson & Robinson July 19, 2011 at 5:28 pm #

      Thanks for your thoughts Louis. The studies you refer were not designed to measure long term alterations in brain structure or functioning. Instead they measure moment to moment changes in blood flow in response to stimuli. The studies cited in our post, in contrast, reflect the type of research needed to assess long-term addictive processes. Such studies have not been done on Internet porn users.

      Internet porn is qualitatively different from sex addiction. Sex is an evolved reward-circuit stimulus; Internet porn is a supranormal version of this stimulus, at least for some users—more akin to junk food in its effects. If sex addiction (human to human) exists, I suspect it is rare. Internet porn use (screen to person) appears to be far more common.

      We own the “Compass of Pleasure”, by David Linden. Chapter four – “your sexy brain” – provides great detail on the neurobiology of love, sex, and sex addiction. On page 118 he emphatically states “Sex addiction is very real, and it takes a terrible toll.” Although he didn’t discuss porn addiction, he made the point that cigarettes are more addictive than heroin because although heroin is a bigger neurochemical “hit” of pleasure, smokers *constantly* train their brains with small hits of pleasure. We think porn addiction may well turn out to be more addictive than Tiger-Woods-style behavior because porn users can train for hours a day and each novel image/video gooses the brain with dopamine, much as constantly puffing cigarettes does.

      In this link (http://www.npr.org/2011/06/23/137348338/compass-of-pleasure-why-some-things-feel-so-good) David Linden the author of “The Compass of Pleasure”, talks with Fresh Air. One subject is sex addiction, which he again says is an addiction. This isn’t a mere opinion. It’s based on actual changes that have to be occurring in the reward circuitry of the brain – which changes have already been seen in other behavioral addictions as outlined in our post.