New study reveals brain differences in sexual desire disorders in men and women

A recent study published in Scientific reports has shed light on the different neural mechanisms underlying hypoactive sexual desire disorder (HSDD) in men and women. Researchers found significant differences in brain activity between the sexes, offering new insights into the condition and paving the way for more targeted treatments.

Sexual desire is a fundamental aspect of human life, crucial for emotional connection, intimacy and overall well-being. HSDD, characterized by a persistent lack of sexual interest that causes significant problems, affects approximately 10% of women and 8% of men. Although the condition is common, relatively little research has been done on it, especially in men. Current treatments are only available to women in the United States, highlighting the need for better diagnostic and therapeutic options for men.

The prevailing theory of HSDD, developed from studies in women, suggests that excessive activation of higher-level brain areas responsible for introspection and self-control leads to decreased activity in lower-level areas involved in emotional and sexual processing. However, this theory does not take into account men with HSDD. To close this gap, the researchers sought to directly compare the neural mechanisms of HSDD in both sexes using functional magnetic resonance imaging (fMRI).

“We are interested in better understanding the areas of the brain that are disrupted in individuals with disturbingly low sexual desire,” said study author Alexander Comninos, professor at Imperial College Healthcare NHS Trust and Imperial College London. “Better understanding will lead to better treatments, as in men there are no approved treatments and in women the treatments (available only in North America) have limited efficacy and carry unwanted side effects such as drowsiness, nausea and syncope, as well as interactions. with alcohol.”

For their new study, the researchers recruited 32 premenopausal women and 32 men, all diagnosed with HSDD and free of psychiatric illness and medications. The participants, who were in a stable relationship, underwent a detailed screening process, including medical history, psychometric questionnaires and blood tests to ensure normal health and rule out endocrine abnormalities.

During the study, participants watched sexual and control videos (exercise) while undergoing fMRI scans. The sexual videos were selected based on focus group ratings of healthy individuals to ensure they were arousing. After each video, participants rated their arousal level. The fMRI scans measured brain activity, focusing on regions associated with sexual and emotional processing.

The study revealed both similarities and differences in brain activation patterns between men and women with HSDD. Both sexes showed similar overall activation patterns in response to sexual stimuli, with increased activity in areas such as the striatum, visual cortex, cerebellum and anterior cingulate cortex. These areas are known to be involved in sexual processing.

However, significant differences emerged in the size and specific areas of activation. Women with HSDD showed greater activation in limbic areas such as the amygdala, striatum and thalamus, which are associated with emotional processing and sexual motivation. In contrast, men showed greater activation in the visual cortex, indicating increased sensitivity to visual sexual cues.

These findings suggest that while women with HSDD may experience more emotional and motivational disturbances related to sexual desire, men may have a disruption in processing visual sexual cues into emotional responses. This difference points to a possible disconnect between visual and emotional systems in men with HSDD.

“In this study, we compared brain responses to erotic videos in women and men with disturbingly low sexual desire,” Comninos told PsyPost. “Broadly speaking, the areas of the brain disrupted by disturbingly low sexual desire appear similar in women and men. However, our data suggest some interesting gender differences. In women, the predominant finding is a top-down inhibition of sexual response, consistent with the previous literature on women. This was demonstrated by the hyperactive frontal gyrus and associations with lower sexual function on psychometric tests in women.”

“However, in men we observed increased activation in the visual cortex (compared to women), suggesting that visual attention to the erotic cues is not effectively transmitted to emotional centers involved in sexual responses. Collectively, these data have clinical implications for the development of new diagnostic and therapeutic approaches for women and men seeking help for distressing low sexual desire.

But like any study, the new study has some caveats. The lack of a control group with normal sexual desire limits the ability to fully understand the differences between individuals with and without HSDD.

Future research should include a control group to directly compare brain activity patterns. Exploring therapies that target specific brain areas or connectivity patterns could also lead to more effective treatments. For example, therapies that improve the connection between visual and emotional centers in the brain may benefit men with HSDD, while approaches that reduce hyperactivity in higher cortical areas or boost activation in limbic areas may be effective for women.

“Our primary goal is to develop much-needed, better tolerated and effective treatments for individuals seeking help for their troubling low sexual desire,” Comninos said. “We have previously shown that kisspeptin, a reproductive protein, when administered can improve sexual brain processing in both women and men with disturbingly low sexual desire. In fact, our studies show that in men with low sexual desire it even has a pro-erectile effect and is very well tolerated.”

“The current study increases our understanding of the core neural disruptions in low sexual desire and gives us confidence that kisspeptin may indeed have therapeutic potential in both women and men, as their disruptions are broadly similar. However, this is just early days and we will continue to work tirelessly on it, as funding allows, because it is a hugely important issue for many people, negatively impacting their quality of life, relationships and in some cases fertility .”

The study, “Women and men with disturbingly low sexual desire exhibit sexually dimorphic brain processing,” was authored by Natalie Ertl, Edouard G. Mills, Matthew B. Wall, Layla Thurston, Lisa Yang, Sofiya Suladze, Tia Hunjan, Maria Phylactou, Bijal Patel, Paul A. Bassett, Jonathan Howard, Eugenii A. Rabiner, Ali Abbara, David Goldmeier, Alexander N. Comninos, and Waljit S. Dhillo.