Addicted to brain scans: the debate about sex addiction reflects a larger cultural confusion.

• Author: Peele, Stanton

LAST JULY, researchers at UCLA reported that the brains of people diagnosed as "hypersexual" do not display distinctive responses to sexual images. The study's authors interpreted their findings as evidence that hypersexuality, defined as a harmful and distressing preoccupation with sex, is not a true addiction or mental disorder.

A week after the UCLA study was published, Ariel Castro pleaded guilty to 937 criminal charges stemming from his kidnapping of three women whom he imprisoned and repeatedly raped over the course of a decade. "I'm not a monster," he insisted at his sentencing hearing. "I'm just sick. I have an addiction, just like an alcoholic has an addiction."

Around the same time, disgraced former congressman Anthony Weiner, who resigned in 2011 after admitting he had "sexted" photos of his genitals to various women, was attempting an improbable political comeback by seeking the Democratic nomination for mayor of New York City. His campaign suffered a major setback when it emerged that Weiner, a married man, had continued conducting virtual liaisons with Internet acquaintances even after quitting Congress.

All of these stories raise the question of how we should view people who don't control their sexual urges. Are they addicted to sex in the same way that an alcoholic is bonded to booze or a junkie is hooked on heroin? If so, does that mean they are no longer responsible for their behavior? And to what extent does neuroscientific evidence such as the electroencephalograms (EEGs) used in the UCLA study illuminate these issues? The debate about the nature of hypersexuality exemplifies a broader cultural confusion about addiction, a concept that has been medicalized to the point that people think it means both less and more than it really does.

If I Only Had a Brain Scan

The UCLA study, reported in the journal Socio-affective Neuroscience and Psychology, involved 52 volunteers whose scores on tests of sexual compulsivity-were similar to those of "people seeking help for hypersexual problems."The researchers, led by the neuroscientist Nicole Prause, hooked the subjects up to electroencephalographs and showed them pictures that ranged from romantic to sexually explicit. Prause and her colleagues found that the brain responses registered by the machines were related to the subjects' self-reported levels of sexual arousal but not to their hypersexuality scores. "Hypersexuality does not appear to explain brain responses to sexual images any more than just having a high libido," Prause said in a university press release.

The researchers presented their results as evidence that hypersexuality is not really an addiction. "A diagnosis of hypersexuality or sexual addiction is typically associated with people who have sexual urges that feel out of control, who engage frequently in sexual behavior, who have suffered consequences such as divorce or economic ruin as a result of their behaviors, and who have a poor ability to reduce those behaviors," the press release noted. But according to Prause and her colleagues, "such symptoms are not necessarily representative of an addiction--in fact, nonpathological, high sexual desire could also explain this cluster of problems."

For someone unblinded by neuroscience, it is hard to make sense of this explanation. Sex addiction is defined by a pattern of behavior, a pattern exhibited by the subjects in this study, who reported that their sexual preoccupations and actions were so unrestrained that these had gotten them into trouble at home or work. Are these problems less real because their EEG tests were not abnormal? If the essence of addiction is a life-disrupting attachment that continues despite undesirable consequences, why does it matter whether Prause's subjects displayed a special "P300 response"?

Prause's reliance on EEG data to cast doubt on the reality of the problems reported by her subjects is an example of what I call "neuroreductionism": the tendency to perceive human experiences as valid or genuine only when they can be linked to measurable brain activity. In their recent book Brainwashed: The Seductive Appeal of Mindless Neuroscience, Oasis Clinic psychiatrist Sally Satel and Emory University psychologist Scott Lilienfeld detail the faulty science and logic underlying this mindset.

Neuroreductionism is the latest twist on the medicalization of addiction. Medicine has come up with wave after wave of biological...