WESTWOOD VILLAGE (CBSLA.com) — A University of California, Los Angeles study suggests that so-called sexual addiction isn’t a real disorder.

Sex addiction, which has been a hot-button issue in the past few years, reportedly affects 16 million Americans, including a number of well-known celebrities such as Tiger Woods, Russell Brand and David Duchovny.

In a recent study, UCLA scientist Nicole Prause monitored the brain activity of 39 men and 13 women—all with sexual image issues—while they were shown various erotic images.

“If you think sexual problems are an addiction, we would have expected to see an enhanced response maybe to those sexual images. If you think it’s a problem with impulsivity, we would have expected to see decreased responses to those sexual images. The fact that we didn’t see any of those relationships suggests that there’s not great support for looking at these sexual behaviors as an addiction,” she said.

Prause said she doesn’t want to discourage people from seeking help, but believes treatment options other than sex rehab should be examined.

“We want to urge caution and thoughtfulness in thinking about how to treat these types of sexual problems, and I don’t think we have a good grasp yet of what exactly is going on,” she said.

Meantime, the American Psychiatric Association excluded sex addiction as a condition in its newly released updated guide.

“There was not sufficient evidence at this time to include sex addiction, not only in the DSM (Diagnostic and Statistical Manual of Mental Disorders) itself, but even in the index for further study, so there’s high skepticism, I would say, around that idea,” said Prause.