Targeting the central melanocortin system for the treatment of metabolic disorders

A large body of preclinical and clinical data shows that the central melanocortin system is a promising therapeutic target for treating various metabolic disorders such as obesity and cachexia, as well as anorexia nervosa. Setmelanotide, which functions by engaging the central melanocortin circuitry, was approved by the FDA in 2020 for use in certain forms of syndromic obesity. Furthermore, the FDA approvals in 2019 of two peptide drugs targeting melanocortin receptors for the treatment of generalized hypoactive sexual desire disorder (bremelanotide) and erythropoietic protoporphyria-associated phototoxicity (afamelanotide) demonstrate the safety of this class of peptides. These approvals have also renewed excitement in the development of therapeutics targeting the melanocortin system. Here, we review the anatomy and function of the melanocortin system, discuss progress and challenges in developing melanocortin receptor-based therapeutics, and outline potential metabolic and behavioural disorders that could be addressed using pharmacological agents targeting these receptors.

Global Consensus Position Statement on the Use of Testosterone Therapy for Women

This Position Statement has been endorsed by the International Menopause Society, The Endocrine Society, The European Menopause and Andropause Society, The International Society for Sexual Medicine, The International Society for the Study of Women's Sexual Health, The North American Menopause Society, The Federacion Latinoamericana de Sociedades de Climaterio y Menopausia, The Royal College of Obstetricians and Gynecologists, The International Society of Endocrinology, The Endocrine Society of Australia, and The Royal Australian and New Zealand College of Obstetricians and Gynecologists.

Treatment for hypoactive sexual desire

Flibanserin acts at cortical, limbic, hypothalamic, and brainstem nuclei to inhibit serotonin release by binding to 5-HT1A autoreceptors and block postsynaptic action of serotonin at 5-HT2A receptors. This gradually disinhibits the turnover of other monoamines like dopamine and noradrenaline that are critical for sexual desire.

[Treatment of premature ejaculation]

Premature ejaculation is the most common sexual dysfunction in men. Its prevalence rate in Europe and in United States is estimated to be between 20% and 30%. The diagnosis of premature ejaculation is based on three main criteria: increased intravaginal ejaculatory latency time (IELT), lack of control over ejaculation and interpersonal psychological disturbances. Premature ejaculation is classified as lifelong (primary) or acquired (secondary) and might be facilitated by chronic prostatitis, diabetes mellitus, hyperthyroidism, obesity. The exact etiology of the disease remains unclear, although 5-HT (5-hydroxytryptamine) receptors are known to have a significant role. The use of SSRIs (selective serotonine reuptake inhibitors) is old and efficient form of therapy for premature ejaculation. Other drugs like tramadol, clomipramine, local anaesthetics and PDE-5 (phosphodiesterase 5) inhibitors also have some efficacy in the treatment of premature ejaculation. To minimize adverse effects the "on demand" therapy is preferred to the daily treatment. Simple questionnaires for patients are used to assess treatment effects.

Sexual desire, sexual arousal and hormonal differences in premenopausal US and Dutch women with and without low sexual desire

The interaction between women's hormonal condition and subjective, physiological, and behavioral indices of desire or arousal remains only partially explored, in spite of frequent reports from women about problems with a lack of sexual desire. The present study recruited premenopausal women at two sites, one in the United States and the other in the Netherlands, and incorporated various measures of acute changes in sexual desire and arousal. A sample of 46 women who met criteria for Hypoactive Sexual Desire Disorder (HSDD) was compared to 47 women who experienced no sexual problems (SF). Half of each group used oral contraceptives (OCs). The specific goal was to investigate whether there is a relationship between women's hormone levels and their genital and subjective sexual responsiveness. Background demographics and health variables, including oral contraceptive (OC) use, were recorded and hormones (total testosterone (T), free testosterone (FT), SHBG, and estradiol) were analyzed along with vaginal pulse amplitude and self-report measures of desire and arousal in response to sexual fantasy, visual sexual stimuli, and photos of men's faces. Self-reported arousal and desire were lower in the HSDD than the SF group, but only for women who were not using oral contraceptives. Relationships between hormones and sexual function differed depending on whether a woman was HSDD or not. In line with prior literature, FT was positively associated with physiological and subjective sexual arousal in the SF group. The HSDD women demonstrated the opposite pattern, in that FT was negatively associated with subjective sexual responsiveness. The findings suggest a possible alternative relationship between hormones and sexual responsiveness in women with HSDD who have characteristics similar to those in the present study.

Role of 5-HT(1A) receptors in fluoxetine-induced lordosis inhibition

The selective serotonin reuptake inhibitor (SSRI), fluoxetine (Prozac(R)), is an effective antidepressant that is also prescribed for other disorders (e.g. anorexia, bulimia, and premenstrual dysphoria) that are prevalent in females. However, fluoxetine also produces sexual side effects that may lead patients to discontinue treatment. The current studies were designed to evaluate several predictions arising from the hypothesis that serotonin 1A (5-HT(1A)) receptors contribute to fluoxetine-induced sexual dysfunction. In rodent models, 5-HT(1A) receptors are potent negative modulators of female rat sexual behavior. Three distinct experiments were designed to evaluate the contribution of 5-HT(1A) receptors to the effects of fluoxetine. In the first experiment, the ability of the 5-HT(1A) receptor antagonist, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide (WAY100635), to prevent fluoxetine-induced lordosis inhibition was examined. In the second experiment, the effects of prior treatment with fluoxetine on the lordosis inhibitory effect of the 5-HT(1A) receptor agonist, (+/-)-8-hydroxy-2-(dipropylamino)tetralin (8-OH-DPAT), were studied. In the third experiment, the ability of progesterone to reduce the acute response to fluoxetine was evaluated. WAY100635 attenuated the effect of fluoxetine; prior treatment with fluoxetine decreased 8-OH-DPAT's potency in reducing lordosis behavior; and progesterone shifted fluoxetine's dose-response curve to the right. These findings are consistent with the hypothesis that 5-HT(1A) receptors contribute to fluoxetine-induced sexual side effects.

[Sexological problems in neurological disorders: neurosexology]

The author has examined this complex subject-matter as he has not found any publications dealing with the interconnection between neurology and sexuality in the Hungarian literature available to him. Healthy sexual behavior determines the individual's quality of life. This, however requires a coordinated, complex functioning bound to very complex structures and their unimpaired functions: peripheral receptor-->peripheral nerve-->radix-->spinal cord-->definite, functionally interrelated structures of the brain (prae-optic areas, hypothalamus, amygdala, limbic system and the cerebral cortex, mainly the orbitofrontal area). The functioning of these structures and the healthy sexuality are also influenced by steroid hormones, neurochemical regulations, neurotransmitters, the monoamin system, opioids, GABA, neuroendocrine hormones (oxytocin, prolactin, gonadotrop realising hormone). The author deals in detail with the impairment for some reason of neurological structures participating in sexuality, which may lead to sexual dysfunctions.

Body image is a major determinant of sexual dysfunction in stable HIV-infected women

BACKGROUND

Prevalence and factors associated with sexual dysfunction in HIV-positive women are poorly known.

METHODS

This was a cross-sectional study in a cohort of HIV-infected women. Clinically stable women were invited to participate in a female sexual dysfunction (FSD) evaluation with Female Sexual Function Index (FSFI) exploring desire, arousal, lubrication, orgasm, pain and satisfaction. An FSFI score <23 was used for defining FSD. Variables evaluated included body appearance satisfaction, interference of body changes with habits, social life and attitudinal aspects of body image, health-related quality of life, hormonal assessment, menopause, cumulative exposure to antiretroviral drug classes and immune-virological parameters. Lipodystrophy was defined according to the HIV Outpatient Study definition.

RESULTS

A total of 185 women completed the FSFI. The mean (+/-SD) age was 42 years (+/-5), 27% had CDC stage C, the mean (+/-SD) CD4+ T-cell count was 508 cells/microl (+/-251) and median HIV RNA was 1.7 log10 copies/ml (interquartile range 1.7-2.6). Among 161 evaluable patients, 59 (32%) reported FSD. In a multiple linear regression analysis, desire, arousal and satisfaction domains were associated with interference of body changes with habits, social life and attitudinal aspects of body image (beta = 0.22, 95% confidence interval [CI] 0.06-0.37; beta = 0.29, 95% CI 0.10-0.48; and beta = 0.20, 95% CI 0.02-0.38, respectively). Lubrication and orgasm domains were associated with body image satisfaction (beta = -0.49, 95% CI -0.88 - -0.10 and beta = -0.58, 95% CI -1.00 - -0.16, respectively). No significant associations with sex hormones, CDC stage, CD4+ T-cell count, HIV RNA viral load and cumulative exposure to antiretroviral drug classes were found. In women with FSD, severity of self-perceived abdominal fat accumulation showed a trend towards lower FSFI scores (ANOVA P = 0.02).

CONCLUSIONS

FSD was highly prevalent in this cohort. Self-perceived body changes was identified as its major determinant.

[Hypothalamus may be involved in psychogenic erectile dysfunction]

OBJECTIVE

To study the changes of hypothalamus metabolism in patients with psychogenic erectile dysfunction (ED) so as to get some clues to the possible pathogenic factors and pathophysiological mechanism of the problem.

METHODS

Six cases of psychogenic ED and 4 normal volunteers were studied by positron emission tomography (PET) for the characteristics of hypothalamus glucose metabolism. Following audiovisual sexual stimulation, the concentration of fluorine-18-fluorodeoxyglucose (18 F-FDG) was determined and the ratio of the left (right) hypothalamus count to the cerebrum count was calculated.

RESULTS

Audiovisual sexual stimulation significantly increased 18F-FDG in the volunteers (left: 1.026 +/- 0.115 vs 2.400 +/- 0.210; right: 1.003 +/- 0.187 vs 2.389 +0.196, P < 0.05) as compared with the psychogenic ED patients (left: 2.781 +/- 0.156 vs 2.769 +/- 0.223; right: 2.809 +/- 0.129 vs 2.793 +/- 0.217, P > 0.05).

CONCLUSION

Psychogenic ED may not be simply a functional disease; the hypothalamus may be involved in the pathophysiology of the problem.

Links among paroxetine-induced sexual dysfunctions, gender, and CYP2D6 activity

The aim of the study was to compare the distribution of therapeutic efficacy and sexual dysfunction during maintenance paroxetine treatment in 17 males and 38 females genotyped and phenotyped to determine their CYP2D6 metabolic status. Clinical results were monitored on scales Clinical Global Impression-Severity of Illness Scale (CGIS) and Arizona Sexual Experience Scale (ASEX). The phenotype procedure showed 7 males and 12 females with extensive metabolic status (EM) and 10 males and 26 females with poor metabolic status (PM). No variation in therapeutic efficacy between male and female subjects classified as PM and those marked as EM was found. A significantly higher rate of sexual dysfunction (p = 0.01) was recorded among females with a PM phenotype.

Testosterone therapy in women: its role in the management of hypoactive sexual desire disorder

Disorders of sexual dysfunction occur in nearly half of women during their life, and hypoactive sexual desire disorder accounts for most of those complaints. Although the relationship between low endogenous testosterone levels and sexual desire disorders in women has not been empirically established, clinical trials have shown that exogenous testosterone therapy improves arousability, sexual desire and fantasy, frequency of sexual activity and orgasm, and satisfaction and pleasure from the sexual act. Its therapeutic role in bone mineral density, fatigue, well-being and hot flashes requires more study before specific recommendations can be made. Potential adverse effects of testosterone therapy include hirsutism, acne and deepening of the voice along with changes in lipid profiles. While less well understood, concern after increased risks for breast cancer and cardiovascular events has been raised about this therapy. Testosterone therapy is available in various formulations; the most commonly used are oral and transdermal, including patches, gels, creams and ointments.

Hormonal changes in menopause and implications on sexual health

INTRODUCTION

The menopause is characterized by an array of changes to the female body caused by modulations which occur in the production of estrogens and androgens. The ovaries are important sites of testosterone production in the peri- and postmenopausal women, but the contribution of testosterone pro-hormones from the adrenal glands falls precipitously to the extent where the ovaries cannot correct the deficit. This results in a net decline in circulating testosterone levels.

AIMS

This paper gives an overview of this interesting subject area. Researchers have cogitated on the relationship between the physical effects of the menopause and the observed declines in testosterone levels, but it is now much clearer that falling testosterone levels cannot explain all of these changes.

MAIN OUTCOME MEASURES

The cessation of follicular functioning results in a steep decline in the production of estrogens. This modulation is responsible for the physical manifestations of the menopause--hot flushes, sleep disturbances, mood changes, bleeding problems, local urogenital problems, vaginal changes, etc.

METHODS

A review of the pertinent literature was conducted to investigate hormonal changes around the menopause. A précis of the salient information is presented here.

RESULTS

Although the most obvious and well-known effects of the menopause are due to the decline of estrogen levels, the effects of falling testosterone levels are subtle, but by no means less significant. Reductions in sexual motivation, sexual arousal, vaginal lubrication, etc. are all associated with plummeting androgen levels.

CONCLUSIONS

Today, several options exist for the treatment of the endocrinological changes associated with the menopause. Estrogen deficiency can be corrected with hormone replacement therapy and topical preparations for the genitalia. A new transdermal system for the administration of testosterone shows a great deal of potential for the treatment of androgen deficiency.

ORIGINAL RESEARCH—WOMEN’S SEXUAL HEALTH: Comparison of Androgens in Women with Hypoactive Sexual Desire Disorder: Those on Combined Oral Contraceptives (COCs) vs. Those not on COCs

INTRODUCTION

Approximately one out of four sexually active women in the United States uses some form of hormonal contraceptive method because they provide the most effective reversible method of birth control available. However, little attention has been paid to possible adverse effects of combined oral contraceptives (COCs) on sexual functioning.

AIM

The aim of this study was to examine the potential effects of COCs on women with hypoactive sexual desire disorder (HSDD). It was hypothesized that female patients with generalized, acquired HSDD on COCs have lower androgen levels than those not on COCs.

METHODS

The patients were healthy premenopausal women with HSDD, aged 22-50 years. Subjects had a history of adequate sexual desire, interest, and functioning. Participants were required to be in a stable, monogamous, heterosexual relationship and were screened for any medication or medical or psychiatric disorders that impact desire. The patients met operational criteria for global, acquired HSDD. The 106 patients were divided into two groups: those on COCs (N = 43) and those not on COCs (N = 63). A two-tailed t-test comparison was made between the two groups comparing free and total testosterone and sex hormone-binding globulin (SHBG).

MAIN OUTCOME MEASURES

The main outcome measures are the differences between the two groups comparing free testosterone, total testosterone, and SHBG.

RESULTS

These patients with HSDD on COCs had significantly lower free and total testosterone levels compared with those who were not on COCs. The SHBG was significantly higher in the group on COCs compared with those who were not on COCs.

CONCLUSION

The result of this study suggests that COCs in premenopausal women with HSDD are associated with lower androgen levels than those not on COCs. Further research is required to determine if low androgen levels secondary to COCs impact female sexual desire.

The Discovery of Small Molecule Inhibitors of Neutral Endopeptidase. Structure-Activity Studies on Functionalized Glutaramides

A series of small molecule glutaramides were synthesized and evaluated for potency against canine and human neutral endopeptidase using target criteria of molecular weight <400 and log P between 2 and 4.5 to maximize the likelihood of achieving good oral absorption. The structure-activity relationship (SAR) investigations described in this paper led to the identification of an ethyl 1,3,4-thiadiazole glutaramide which demonstrated good neutral endopeptidase potency, selectivity and excellent oral absorption in the rat.

Appetitive responses to sexual stimuli are attenuated in individuals with low levels of sexual desire

Despite the high prevalence of sexual desire disorders, little is known about their biological underpinnings in humans. Animal studies suggest that dopamine is involved in appetitive sexual behavior; thus, one aim of this study was to elucidate that relationship in humans. This study used measurement of the acoustic startle response (ASR) and prepulse inhibition of the startle response (PPI) as psychophysiological indicators of changes in motivational states to assess the potential relation between sexual desire and appetitive motivation in humans. Responses to sexually provocative stimuli consisting of single nude men and single nude women in a sample of 153 participants (77 men, 76 women) were assessed. The results indicated that ASR was attenuated after exposure to appetitive stimuli (i.e., sexually provocative pictures of attractive individuals) to a greater extent among participants with higher levels of sexual desire, as measured by the Sexual Desire Inventory-2 (Spector, I. P., Carey, M. P., & Steinberg, L. (1996). Journal of Sex & Marital Therapy, 22, 175-190). In addition, PPI was inversely associated with subjective ratings across stimuli such that greater subjective levels of desire were correlated with lower levels of PPI. In general, these results suggest that individuals with lower levels of sexual desire may have a diminished physiological response to appetitive sexual stimuli.

[1H-MRS of the hippocampus of psychogenic erectile dysfunction]

OBJECTIVE

To study the changes of the hippocampus metabolites with MRS to provide some clues for exploring the possible underlying unrecognised factors and pathophysiological mechanisms of psychogenic erectile dysfunction (ED).

METHODS

Fifteen cases of psychogenic erectile dysfunction and 15 normal volunteers (the control) were studied by a clinical 1. 5T MRI/MRS system. Proton multi-voxel spectroscopy imaging (1H-MRSI) was obtained from both sides of the hippocampus region. N-acetylaspartate (NAA), creatine and phosphocreatine (Cr) and choline-containing compounds (Cho) were determined and the ratios of NAA/Cr and Cho/Cr were calculated respectively.

RESULTS

The NAA/Cr ratio was significantly lower in the ED patients than in the control (P < 0.05). There was no significant difference in the Cho/Cr ratio between the two groups (P > 0.05).

CONCLUSION

Psychogenic erectile dysfunction may not be simply a functional disease. The hippocampus may be involved in the pathophysiology of psychogenic ED. The disease may have some previously unrecognised underlying aetiological factors and pathophysiological mechanisms.

Women with low libido: correlation of decreased androgen levels with female sexual function index

The aim of the present study was to investigate a possible correlation between decreased androgen levels and female sexual function index (FSFI) in women with low libido and compare these findings with normal age-matched subjects. In total, 20 premenopausal women with low libido (mean age 36.7; range 24-51 y) and 20 postmenopausal women with low libido (mean age 54; 45-70 y), and 20 premenopausal healthy women (mean age 32.2; range 21-51 y) and 20 postmenopausal healthy women (mean age 53.5; range 48-60 y) as controls were enrolled in the current study. Women with low libido had symptoms for at least 6 months and were in stable relationships. All premenopausal patients had regular menstrual cycles and all postmenopausal patients and controls were on estrogen replacement therapy. None of the patients were taking birth control pills, corticosteroids or had a history of chronic medical illnesses. All completed the FSFI and Beck's Depression Inventory (BDI) questionnaires. Hormones measured included: cortisol; T3, T4 and TSH; estradiol; total and free testosterone; dehydroepiandrosterone sulfate (DHEA-S); sex hormone binding globulin (SHBG). We performed statistical analysis by parametric and nonparametric comparisons and correlations, as appropriate. We found significant differences between the women with low libido and the controls in total testosterone, free testosterone and DHEA-S levels and full-scale FSFI score for both pre- and postmenopausal women (P<0.05). In addition, decreased total testosterone, free testosterone and DHEA-S levels positively correlated with full-scale FSFI score and FSFI-desire, FSFI-arousal, FSFI-lubrication and FSFI-orgasm scores (P<0.05). Our data suggest that women with low libido have lower androgen levels compared to age-matched normal control groups and their decreased androgen levels correlate positively with female sexual function index domains.

Sexual function and dysfunction in women

Multiple factors may affect sexual functioning in women, requiring a thorough assessment of all possible etiologies to guide appropriate treatment. Interventions may also be multifaceted, ranging from sex education to psychotherapy to medical treatment. Restoration of sexual functioning is the goal of treatment, but more research is needed for true success to be realized.

In the mood for sex: the value of androgens

Androgen substitution is increasingly being employed to enhance sexual desire in women based on the assumption that low androgen levels cause low sexual desire. Sexual functioning in women is complex; therefore, decreased sexual interest can have various causes. An adequate female sexual biopsychosocial model that includes the role of androgens has not yet been developed. Moreover, a higher or lower degree of sexual desire does not form a measure for sexual satisfaction. One group of women at risk for androgen deficiency are women with pathophysiological problems that affect androgen production in the ovaries and/or adrenal glands. The available literature indicates that androgen substitution, despite leading to supraphysiological androgen levels, improves some aspects of sexual functioning, especially in women who have undergone oophorectomy. What this means in terms of satisfaction with sexual functioning in these women is not clear. We believe that, from an evidence-based point of view, testosterone substitution should only be administered as adjuvant treatment to sexological counseling in women with low libido in combination with low bioavailable androgen levels because of insufficiency of ovarian and/or adrenal function and normal estrogen levels. The routine administration of androgens to endocrinologically healthy women who have complaints of decreased sexual interest is not based on available evidence.

Biochemical and physiological mechanisms of female genital sexual arousal

Limited studies are available concerning physiological and biochemical mechanisms involved in female sexual function and dysfunction. The paucity of physiological and biochemical data pertaining to genital sexual arousal function is attributed, in part, to lack of reliable experimental models and tools for the investigation of female sexual arousal. This review summarizes research efforts from a number of laboratories in which several experimental models have been established. These include the development of in vivo animal models, organ bath studies, and the establishment of cell cultures. The availability of such experimental model systems have facilitated efforts aimed at defining the neurotransmitters responsible for vaginal smooth muscle relaxation, the role of sex steroid hormones and their receptors in modulating genital hemodynamics, smooth muscle contractility, and neurotransmitter receptor expression. A comprehensive and integral understanding of female sexual function requires detailed investigation of the vascular, neurological (central and peripheral), and structural components of this complex physiological process.

The medicalization of female sexual dysfunction: the need for caution

The use of drugs such as Viagra to treat sexual dysfunction in women may be beneficial in a proportion of cases. However, there are a number of barriers to understanding and predicting which women are likely to benefit, and caution is required in approaching this clinical issue. Three relevant issues are discussed: (1) Male-female differences in sexuality. Three complimentary ways in which male and female sexuality differs are considered--women have less need for their sexuality to be influenced by reproductive hormones; their needs for sexual enjoyment and orgasm are not well met by conventional vaginal intercourse; and, as a result of the disjunction between female sexual response and reproduction and a possibly greater propensity for central inhibition of sexual response, women are more susceptible to the repressive effects of social constraints on sexuality; (2) Sex therapy. While conventional forms of sex therapy are well designed to address the particular psychological needs of women as well as men, the interface between psychological processes and physiological response is not well understood. For the same reason, we should expect difficulty in predicting when pharmacological effects on sexual response will be beneficial; (3) When is a sexual problem a sexual dysfunction? It is likely that many cases of impaired sexual response or interest in women are psychologically understandable and hence adaptive reactions to problems in the sexual relationship, and hence not dysfunctions. Until we can distinguish between such adaptive inhibitions of response and those that are maladaptive dysfunctions, we will have difficulty in predicting when pharmacological treatment will be helpful.

[Sexual side effects of antidepressants]

Most antidepressant drugs have some sexual side effects. These side effects are caused by an increased neurotransmission of serotonin in the central nervous system, a stimulating effect at postsynaptic serotonin receptors and effects on the peripheral nervous system. Antidepressant-induced sexual disorders may impair patient compliance. Publications on sexual side effects are mainly case reports and few double blind placebo-controlled trials. This hampers generalisation of findings. The best treatment consists of prescribing another antidepressant which probably has hardly any or no sexual side effects. However, this entails the risks of reduced antidepressant effects and of non-sexual side effects. The extent of sexual side-effects among the serotonin reuptake inhibitor seems to differ. Antidepressants with few or no sexual side effects include those with noradrenergic and dopaminergic action (some tricyclic antidepressants, bupropion), as well as antidepressants with a postsynaptic receptor blocking action (nefazodone and mirtazapine).

A possible dopaminergic mechanism in the serotonergic antidepressant-induced sexual dysfunctions

The administration of antidepressant serotoninergic medication is associated with the presentation of sexual dysfunctions. This seems to be mediated by the activation of the 5-HT2 receptors. Segraves (1995) has proposed that the inhibition of noradrenergic transmission by serotonin may be the mechanism which causes the antidepressant-induced sexual dysfunctions. The inhibition which the 5-HT2 receptors carry out on dopaminergic transmission leads us to propose this mechanism as also participating in the antidepressant-induced sexual dysfunctions.

Gonadal steroid and gonadotropin response to dexamethasone: a study in sexual dysfunction and normal controls

Numerous investigations have reported an alteration of hormonal response to dexamethasone in depressive disorder. No such data are available in psychogenic sexual dysfunction. Pre- and postdexamethasone levels of testosterone, estradiol, LH and FSH were studied in 20 male patients with sexual dysfunction and 20 male healthy controls. Dexamethasone had no influence on testosterone, estradiol, LH and FSH in normal controls. The patients showed an increase in testosterone and LH but not in FSH levels in the morning after dexamethasone administration. When compared with basal levels, the increase in postdexamethasone levels in sexual dysfunction was significant for testosterone (delta T) but not for LH (delta LH). The altered gonadal steroid and gonadotropin response to dexamethasone in sexual dysfunction might be due to disturbances of dexamethasone metabolism and glucocorticoid receptor density comparable to similar findings in depressive disorder.