Interdisciplinary Approaches to Understanding Women’s Sexual Health: Interview with Tierney Lorenz
Updated: Mar 31, 2022
This month, we spoke with Dr. Tierney Lorenz, PhD, an assistant professor at the University of Nebraska-Lincoln who specializes in women’s sexual and behavioral health. We talked with Dr. Lorenz about her wide-ranging research including studies on the impact of sexual trauma on the arousal response, the gap between vaginal arousal and subjective arousal, and how the health of the vaginal biome may affect sexual arousal.
Dr. Lorenz is an Assistant Professor of in the Clinical Psychology and Neuroscience & Behavior programs at the University of Nebraska-Lincoln and core member of the Center for Brain, Biology & Behavior. She is the Director of the Women, Immunity and Sexual Health (WISH) lab, which investigates the ways that sexual behavior impact women's immune and endocrine function, as well as ways to help women with mental and/or physical health conditions have happy, healthy sexual lives. WISH lab research draws from evolutionary and feminist science perspectives, and uses methods from multiple fields, including measures of hormones and immune markers, psychophysiological measures of sexual and autonomic arousal, clinical trials, surveys and interviews, and more.
SHWI: You’ve built your career around understanding how libido is affected by different physical and emotional states. Can you give us a little bit of background on the range of research you’ve done?
The Women, Immunity and Sexual Health (WISH) Lab is an interdisciplinary lab that studies the interactions between women’s sexual and reproductive health, and mental and physical health. We investigate the ways that sexual behavior impacts women's immune and endocrine function, as well as ways to help women with mental and/or physical health conditions have happy, healthy sexual lives. We also focus on helping survivors of sexual trauma through basic science and clinical research. This has included a range of studies, including:
Psychophysiological studies of vaginal arousal and orgasm.
Neuroimmune and neuroendocrine contributions to women’s sexual desire and arousal.
Clinical trials to test psychological and behavioral treatments for sexual side effects of antidepressants and following sexual trauma.
Observational studies of the dynamics between women’s mood, sexual wellbeing, and immune function over the course of the menstrual cycle.
Evolutionary models of interactions between women’s reproductive and immune systems.
SHWI: One of the most striking results of your long-time work that you've shared with us is the frequency of sexual trauma that women have experienced. Can you talk more about that and how it shows up in their arousal response?
It is remarkable how many women report unwanted sex. The most widely-cited statistics on sexual assault and rape state that up to 1 in 4 girls and women will experience sexual violence in their lifetimes. In our lab, however, we measure not only overt forms of sexual trauma (like forceable rape), but also intoxication-related assault, coercion, and other forms of unwanted sexual activity, like stealthing (when someone removes a condom during sex without the knowledge or consent of their partner) or safety sex (when someone has sex to prevent their partner from getting mad and hurting them). When we include these more ambiguous forms of unwanted sex, the rates are much higher, closer to 1 in 2. And even that number is, sadly, probably an underestimate because many women are too ashamed to report their experiences, even on anonymous surveys. Unwanted sex has a range of effects on women’s sexual wellbeing. When unwanted sex leads to post-traumatic stress symptoms, it can contribute to low arousal by changing the relative balance of autonomic nervous system activation – that is, if the body is in fight-or-flight mode when presented with a sexual cue, it is difficult to generate the changes in genital blood flow that contribute to sexual arousal.
We have found that for women without post-traumatic stress symptoms, moderately elevated sympathetic activity (e.g., by going for a jog before sex) can increase vaginal arousal during sex. But for women with sexual trauma histories, their sympathetic nervous system is already over-active, and the further elevation from possible reminders of their trauma during sex may push them over the range that helps facilitate arousal. So for these women, we advise slowing down and finding ways to calm the stress system. There are other ways that unwanted sex can shape women’s sexual response. An upcoming paper from our lab looks at the ways that unwanted sex might influence women’s sexual self-schema – that is, how women think and feel about themselves as sexual beings. We found that women with unwanted sex histories might have more complicated, ambiguous feelings about sex – both very positive, but also very negative – and this in turn influences their level of sexual desire.
SHWI: We know that you have one of the most well equipped labs in the nation to understand the biomechanical arousal response. Can you talk about the discrepancy between women’s subjective experience and their physiological response? What do you think accounts for this discrepancy?
There is a growing research literature on why there is a wider gap between vaginal arousal and subjective arousal than what we see for folks with penises (generally men). Some researchers think it may be a function of what men and women use to determine their subjective arousal – that men focus more on their genital sensation while women are taught to pay more attention to non-physical cues, particularly related to how their body looks or how close or intimate they feel with their partner. Others think it may be a byproduct of our evolution, as a protective response to potential rape. These theories argue that, if an unaroused vagina is harmed during unwanted sex, it would make sense to adapt to a world in which unwanted sex is frequent by becoming aroused to any sexual stimulus, even those that are not wanted. This “prepared for anything” hypothesis is somewhat controversial, though, because there is a lot more research that would need to be done to support it. Still other researchers speculate that this may be a function of the wider range of stimuli that women find sexually arousing even if they don’t find it mentally appealing – including, potentially, sexual stimuli that feature other women. This line of work seems especially interesting, as it implies that the well-documented higher rates of bisexuality in women may reflect a broader tendency towards sexual arousal under dynamic conditions.
SHWI: How do you speculate how the health of the vaginal biome impacts sexual arousal?
Some of our work suggests that arousal may contribute to vaginal inflammation responses, and vice versa – that the body uses information about sexual arousal to coordinate immune responses. This may help to prevent accidental immune interference with implantation. If the vaginal immune system has advance warning that sperm may be coming, it can “stand down” it’s generic defenses temporarily and avoid attacking those sperm (which otherwise look a lot like invaders!).
For example, in women who are frequently sexually active, lower inflammation leads to higher vaginal arousal to a sexual cue and higher arousal stimulates a significant decrease in inflammation. So a healthy biome likely sets the stage for this important cross-talk between the arousal system and the immune system – if there is dysbosis, this leads to a lot of baseline inflammation that may be difficult to regulate during arousal.
SHWI: What do you think are the most important research questions that need to be addressed to improve women’s vaginal health?
How does the reproductive system work with other systems – particularly the endocrine, immune, and nervous systems – to coordinate important behaviors and overall health? We are becoming increasingly aware that many of the mood disorders that occur around reproductive transitions (such as puberty, pregnancy, and menopause) may be due to complex interactions between women’s hormones, immune function, and central nervous system. How can we harness the integration across these systems to improve women’s sexual, mental, and physical health during these transitions and beyond?
SHWI: What do you believe is some of the most important recent research that has been done in the last five years in support of women's vaginal and reproductive health?
The incredible work coming out of the Center for Sexual Health Promotion is certainly on that list! They have contributed a great deal to wider recognition of how objectification changes how women understand their own bodies and how this shapes how they view their vaginas, what sorts of products they use for vaginal health, and whether or not they consider vaginal pain to be “normal”. Debby Herbenick and the CSHP’s work on sexual and reproductive health knowledge in emerging adult women shows that even though we live in an increasingly connected world, there are still huge gaps in women’s access to basic information on how the vagina and clitoris work and what brings pleasure.