(001) INHIBITION AND EXCITATION IN THE SEXUAL BRAIN: AN USEFUL TOOL FOR THE PREDICTION OF THE DIAGNOSIS AND TREATMENT OF HYPOACTIVE SEXUAL DESIRE IN WOMEN WITH SEXUAL DYSFUNCTION
Authors: Maseroli E , Cipriani S , Lanzi V , Vignozzi L 
Published: June 2024

Abstract

Introduction
HSDD (Hypoactive Sexual Desire Disorder) is one of the most common sex-related disorders among women. Despite its considerable prevalence, factors affecting sexual desire as well as therapeutic outcomes of treatment of HSDD in women have been scarcely studied. According to the Dual Control Model (DCM), for years female sexual desire has been identified as the result of two mainly centrally acting brain processes: excitation or inhibition towards sexual cues. In this context, the SIS (Sexual Inhibition Scale)/SES (Sexual Excitation Scale) validated questionnaire could represent an useful tool for the clinician to better characterize patients’ lack of desire.

Objective
This study was aimed at exploring both the inhibitory and excitatory components of sexual desire in women referring to our Clinic for sexual dysfunction, in order to find a cut-off value in the SIS/SES score predicting a diagnosis of HSDD. A secondary aim was also to identify clinical, relational and biochemical parameters significantly associated with these two dimensions of sexual desire.

Methods
We retrospectively recruited a consecutive series of 133 women consulting for Female Sexual Dysfunction (FSD). Patients underwent clinical and biochemical evaluation, a structured interview and completed several self-administered questionnaires, including SIS/SES, Female Sexual Function Index (FSFI), Female Sexual Distress Scale-Revised (FSDS-R), Body Uneasiness Test (BUT), Emotional Eating Scale (EES) and Middlesex Hospital Questionnaire (MHQ).

Results
The ROC curve for SES score showed an accuracy of 0.687 ± 0.05 (p&lt;0.0001) in identifying HSDD; considering a cut-off value of 47.5, the sensitivity and specificity for HSDD detection were 70.5% and 55.6%, respectively. In addition, the best cut-off value for SIS1 to diagnose HSDD was 32.5, with 0.664 ± 0.048 AUC (p=0.002), 68.2% sensitivity and 53.3% specificity. We next stratified FSD women according to these SES/SIS1 cut-off values, thus identifying patients with pathological (pSES, pSIS1) or non-pathological (npSES, npSIS1) scores and the following 4 different subgroups: group 1 npSES/npSIS1; group 2 npSES/pSIS1; group 3 pSES/npSIS1; group 4 pSES/pSIS1. Among the 4 groups we did not find any statistically significant difference concerning the main characteristics explored, including lifestyle, hormonal and metabolic factors, with the exception of age, which was associated with a progressive worsening of either SES and SIS1 scores (F=4.299, p=0.006). Concerning relational factors, we demonstrated that the longer the duration of the relationship, the more pathological the excitatory/inhibitory scores, even when adjusted for age (F=5.588, p=0.001). Noteworthy, with exception for FSFI orgasm (FSFI-O) and satisfaction (FSFI-S) domains, all others FSFI domains scores showed similar significant differences with the worst values observed in pSES subgroups, independently from the presence of pSIS1. In contrast, FSDS-R score showed a highly significant variation among subgroups, but with the pSIS1 subgroup displaying the worst distress score independently from the presence of pSES. Among endocrinological factors, only total testosterone levels showed significant variation among groups (F=5.952, p&lt;0.001), with the lower level observed in FSD women with pSES or pSIS1, in whatever combination as compared to npSES/npSIS1, even after age-adjustment (F=3.176, p=0.027). Regarding psychopathological factors, in an age-adjusted model, we found a significantly different MHQ total score among the 4 groups, with the worst value associated with the pSIS1 group combined or not with pSES. We also explored eating disorder symptoms. The 4 groups reported significantly different values in the EES, with pSES/pSIS1 group showing the highest score, even after adjusting for age (F=3.316, p=0.023). We then investigated the relevance of stratifying HSDD patients according to SIS1 and SES np/p scores in predicting the beneficial effects of treatments for HSDD (improvement yes/no). Interestingly, we found that SES, but not SIS scores, could predict HSDD treatment outcome after 6 months; in particular, the lower the level of SES at baseline, the higher the improvement in FSFI-D domain during treatment is predictable. Finally, we explored which were the main determinants for SES/SIS1 scores in the study population. Noteworthy, a significantly stepwise increase of SES score was observed as a function of total testosterone levels (r=0.192, p=0.049).

Conclusions
In conclusion, the cutoffs of SIS1/SES found in this study could help characterizing HSDD women and identifying subgroups of patients with the highest probability to benefit from testosterone treatment. From a broader viewpoint, our study suggests that women diagnosed with HSDD should be evaluated by using more appropriate tools, including those not routinely employed in clinical practice, so that different “nuances” of this sexual disorder could be recognized and consequently adequately treated in a tailored therapy perspective.

Disclosure
No.