Does sex addiction really exist? A new study published in last week’s journal of Socioaffective Neuroscience and Psychology suggests that maybe it doesn’t—bad news for celebrities like Tiger Woods and Russell Brand who have made it trendy in recent years to claim a clinical addiction to sex as an explanation for sexual misbehavior.

The study (which, amazingly, is the first of its kind) measured how the brains of people who struggle with sexually compulsive behavior respond to sexual images. If sex can be addictive in the clinical sense, scientists theorized, then the neural response of sex addicts to pornography should mimic the neural responses of drug or alcohol addicts to their drugs of choice. Instead, researchers found that hypersexual brains don’t react in the same way as other addicts’ brains—in fact, the neural responses to pornography only varied based on levels of sexual libido, rather than on measures of sexual compulsivity. People with higher libidos had more active brain reactions to the sexual images than people with lower libidos, but that was the only correlation. Degrees of sexual compulsivity did not predict brain response at all. If the results of this first study can be replicated, it would represent a major challenge to the notion that sex and pornography can be literally addictive.

“This is controversial territory because it represents a substantial shift in the way we view mental illness,” Dr. Nicole Prause, an assistant research scientist in the department of psychiatry at UCLA and one of the investigators involved with the study, told me. “Most people describe high-frequency sexual problems as an ‘addiction’—that’s how the public and even many clinicians talk about it. But this data challenges the addiction model and forces us to reconsider how we think and talk about these problems.”

Read it at Slate.