There is a lot of controversy about sexual addiction, which has been blamed for ruining relationships, lives and careers. Is it a mental disorder or something else?
In a new study researchers from the University of California-Los Angeles measured how the brain behaves in so-called “hypersexual” people who have problems regulating their viewing of sexual images. They found that the brain response of these individuals to sexual images was not related in any way to the severity of their hypersexuality.
Instead it was tied only to their level of sexual desire.
In other words, hypersexuality did not appear to explain brain differences in sexual response any more than having a high libido, said senior author Nicole Prause, Ph.D., a researcher in the department of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA.
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;
- whose ability to reduce those behaviors is poor.
But such symptoms are not necessarily representative of an addiction. In fact, non-pathological, high sexual desire could also explain this cluster of problems, according to Prause.
One way to tease out the difference is to measure the brain’s response to sexual images in individuals who acknowledge having sexual problems, she said.
If they suffer from hypersexuality, or sexual addiction, their brain response to visual sexual stimuli could be expected be higher, in much the same way that the brains of cocaine addicts have been shown to react to images of the drug.
The study involved 52 volunteers: 39 men and 13 women, ranging in age from 18 to 39, who reported having problems controlling their viewing of sexual images.
The subjects filled out four questionnaires covering various topics, including sexual behaviors, sexual desire, sexual compulsions, and the possible negative cognitive and behavioral outcomes of sexual behavior. The participants had scores comparable to individuals seeking help for hypersexual problems, the researchers noted.
While viewing the images, the volunteers were monitored using electroencephalography (EEG), a non-invasive technique that measures brain waves. The researchers measured event-related potentials, brain responses that are the direct result of a specific cognitive event.
“The volunteers were shown a set of photographs that were carefully chosen to evoke pleasant or unpleasant feelings,” Prause said. “The pictures included images of dismembered bodies, people preparing food, people skiing — and, of course, sex. Some of the sexual images were romantic images, while others showed explicit intercourse between one man and one woman.”
The researchers were most interested in the response of the brain about 300 milliseconds after each picture appeared, commonly called the “P300” response. This basic measure has been used in hundreds of neuroscience studies internationally, including studies of addiction and impulsivity, Prause said.
The P300 response is higher when a person notices something new or especially interesting to them.
The researchers expected that P300 responses to the sexual images would correspond to a person’s sexual desire level, as shown in previous studies.
They further predicted that P300 responses would relate to measures of hypersexuality. That is, in those whose problem regulating their viewing of sexual images could be characterized as an “addiction,” the P300 reaction to sexual images could be expected to spike.
Instead, the researchers found that the P300 response was not related to hypersexual measurements at all — there were no spikes or decreases tied to the severity of participants’ hypersexuality. So while there has been much speculation about the effect of sexual addiction or hypersexuality in the brain, the study provided no evidence to support any difference, Prause said.
“The brain’s response to sexual pictures was not predicted by any of the three questionnaire measures of hypersexuality,” she said. “Brain response was only related to the measure of sexual desire. In other words, hypersexuality does not appear to explain brain responses to sexual images any more than just having a high libido.”
“If our study can be replicated, these findings would represent a major challenge to existing theories of a sex ‘addiction,’ ” she concluded.
The study was published in the journal Socioaffective Neuroscience and Psychology.