While I was tempted to run with these corroborating accounts, I recognized that anecdotes were just that, and I wanted to see more rigorous investigations before drawing any conclusions.

The critics of YourBrainOnPorn.com feel the same way. They point out that there has never been a study that specifically examines the brain changes of Internet porn users with the scientific robustness of a randomized control trial, so the brain changes that Wilson and Robinson speculate are occurring in heavy porn-users have not actually been observed.

It's true, but that standard might not be feasible here. In 2009, University of Montreal professor Simon Lajeuness tried to set up such a study , but was thwarted because he "could not find any adult men who had never viewed sexually explicit material."

In lieu of such a study, Wilson and Robinson link to a slew of studies that show how the underlying brain changes observed in all addicts have already been seen in the brains of overeaters, compulsive gamblers, video gamers, and more recently in "Internet addicts" (including porn-watchers).

These changes include desensitization (reduced responsiveness to pleasure), sensitization (hyper-reactivity to addiction-related cues), abnormal white matter (a weakening of the communication between reward circuits and the frontal cortex) and hypofrontality (a decrease in frontal-lobe gray matter that is involved in impulse control and decision-making).

Still, the lack of scientifically rigorous research that isolates Internet porn users from other "Internet addicts" has forced Wilson and Robinson to cite testimonials -- and is why the couple's detractors cry "anecdotal pseudoscience!" and "mass hypochondria!" Sometimes, Wilson and Robinson do seem to get carried away, like by claiming that ex-Internet porn addicts are a valid, albeit "informal," control group to study this phenomenon (but, of course, they're not randomly selected, so there may be a common trait among these folks that made them use and stop using that could affect their results).

If the duo comes off as overzealous in their defense of the legitimacy of porn addiction, it may be because their counterparts are so dogmatically dismissive. Well-known sex therapist Dr. Marty Klein argues in The Humanist that these "addictions" are likely secondary to other root causes like bipolar disorder, OCD, borderline personality disorder, or just masturbating too much, and that focusing on porn masks the problem -- and the individual's responsibility to deal with his own immature decision-making. Dr. Klein categorically refutes the addiction model, stressing that most people who watch porn have no problem with it. He declares, "[U]sing porn does NOT cause brain damage, erectile dysfunction, or loss of sexual interest in one's mate."

Klein elaborated on his perspective on a January episode of the Savage Love Podcast with the celebrated sex advice columnist Dan Savage (who backs him up):

When a lot of people who label themselves as sex addicts or porn addicts say, "I'm out of control," what they're really mean is "You know, it would be really uncomfortable to make different decisions about sex than the ones that I'm making. When I'm lonely it would be really uncomfortable to not look at porn."

On air, Dr. Klein constructed a straw man of a porn addict who is too undisciplined "to stop looking at porn for five minutes," too unwilling to address the emotional roots of his behavior, and too socially inhibited to have a "decent" relationship alternative. I was feeling exhausted at the thought of contorting myself to fit this description, but gave up even trying when Dr. Klein informed me by email that I was more alone than I thought: "[I] do NOT see the epidemic of young men with porn-created erection problems that Robinson wants to help ... she's probably making a sampling error."