A missense polymorphism in the putative pheromone receptor gene VN1R1 is associated with sociosexual behavior.

Pheromones regulate social and reproductive behavior in most mammalian species. These effects are mediated by the vomeronasal and main olfactory systems. Effects of putative pheromones on human neuroendocrine activity, brain activity and attractiveness ratings suggest that humans may communicate via similar chemosignaling. Here we studied two samples of younger and older individuals, respectively, with respect to one nonsynonymous polymorphism in the gene encoding the human vomeronasal type-1 receptor 1, VN1R1, and one nonsynonymous polymorphism in the gene encoding the olfactory receptor OR7D4. Participants in both samples had self-reported their sociosexual behavior using the sociosexual orientation inventory, including questions regarding lifetime number of one-night stands, number of partners last year and expected number of partners the coming 5 years. In women, there was a significant association between the VN1R1 polymorphism and sociosexual behavior in both samples, driven specifically by the question regarding one-night stands. Our results support the hypothesis that human social interaction is modulated by communication via chemosignaling.

Female sexual function varies over time and is dependent on partner-specific factors: a population-based longitudinal analysis of six sexual function domains.

BACKGROUND: Most studies examining female sexual functions (FSFs) have used cross-sectional designs, not allowing for studying temporal stability and possible relationships between different FSFs over time. Our aim was to study these relationships using a longitudinal approach. METHOD: The study sample consisted of 2173 Finnish women from two large-scale, population-based data collections 7 years apart. The Female Sexual Function Index was used. Analyses were further conducted separately for women in different relationship constellations. RESULTS: Standardized autoregressive paths ranged from 0.136 (sexual satisfaction) to 0.447 (orgasm function) in the full sample, suggesting that most of the variance in FSF was explained by something other than previous function. Orgasm, desire and satisfaction were the strongest predictors of other functions in the full sample and for women in the same relationship at both time points (higher orgasm function predicted higher function in other domains; greater sexual desire and satisfaction predicted lower function in other domains), however, with small effects sizes. For single women, orgasm function and sexual desire were the only significant autoregressive paths. Significant unidirectional cross-domain paths were found for women in the same relationship at both time points. One significant cross-domain path, not confirmed as unidirectional, was found for single women. CONCLUSIONS: FSFs varied considerably over 7 years and relationship status was of importance when assessing temporal stability and cross-domain effects. Our results advocate tailored psychobehavioural treatment interventions for female sexual dysfunctions that take partner-specific factors into account.

Antidepressant treatment of premature ejaculation: discontinuation rates and prevalence of side effects for dapoxetine and paroxetine in a naturalistic setting.

The present study aimed to investigate prevalence of and reasons for selective serotonin reuptake inhibitor (SSRI) discontinuation, and compare the two most common SSRIs used in premature ejaculation (PE) treatment, in naturalistic settings (that is, outside clinical trials). The sample consisted of 132 Finnish men with a mean age of 42.5 years (s.d. = 10.6) who had received medical treatment for lifelong PE. The men were enlisted for the study after identifying individuals from the third author's (a physician specializing in sexual medicine) patient registry. Participants responded to a secure, online questionnaire. PE treatment-related side effects of, and discontinuation rates for, different SSRIs were retrospectively self-reported. Treatment efficacy and happiness with treatment were retrospectively self-assessed. Discontinuation rates were uniformly high, ranging from 28.8 to 70.6% between different SSRIs. Dapoxetine was associated with the highest dropout rates (70.6%), and paroxetine the lowest, discontinuation rates. Limited efficacy and side effects were the most common reasons for discontinuation. Paroxetine was more effective and better tolerated than dapoxetine. A considerable number of patients chose to spontaneously discontinue treatment, especially so in the case of dapoxetine, corroborating recent studies conducted in naturalistic settings. Further research efforts are necessary to develop new and improve existing PE treatment alternatives.

Alcohol and aggressive behavior in men--moderating effects of oxytocin receptor gene (OXTR) polymorphisms.

We explored if the disposition to react with aggression while alcohol intoxicated was moderated by polymorphic variants of the oxytocin receptor gene (OXTR). Twelve OXTR polymorphisms were genotyped in 116 Finnish men [aged 18-30, M = 22.7, standard deviation (SD) = 2.4] who were randomly assigned to an alcohol condition in which they received an alcohol dose of 0.7 g pure ethanol/kg body weight or a placebo condition. Aggressive behavior was measured using a laboratory paradigm in which it was operationalized as the level of aversive noise administered to a fictive opponent. No main effects of the polymorphisms on aggressive behavior were found after controlling for multiple testing. The interactive effects between alcohol and two of the OXTR polymorphisms (rs4564970 and rs1488467) on aggressive behavior were nominally significant and remained significant for the rs4564970 when controlled for multiple tests. To the best of our knowledge, this is the first experimental study suggesting interactive effects of specific genetic variants and alcohol on aggressive behavior in humans.

Correlated genetic and non-shared environmental influences account for the co-morbidity between female sexual dysfunctions.

BACKGROUND: Previous studies have shown moderate heritability for female orgasm. So far, however, no study has addressed the pattern of genetic and environmental influences on diverse sexual dysfunctions in women, nor how genetic and environmental factors contribute to the associations between them. METHOD: The sample was drawn from the Genetics of Sex and Aggression (GSA) sample and consisted of 6, 446 female twins (aged 18-43 years) and 1994 female siblings (aged 18-49 years). The participants responded to the Female Sexual Function Index (FSFI), either by post or online. RESULTS: Model fitting analyses indicated that individual differences on all six subdomains of the FSFI (desire, arousal, lubrication, orgasm, satisfaction, and pain) were primarily due to non-shared (individual-specific) environmental influences. Genetic influences were modest but significant, whereas shared environmental influences were not significant. A correlated factors model including additive and non-additive genetic and non-shared environmental effects proved to have the best fit and suggested that both correlated additive and non-additive genetic factors and unique environmental factors underlie the co-occurrence of the sexual function problems. CONCLUSIONS: The findings suggest that female sexual dysfunctions are separate entities with some shared aetiology. They also indicate that there is a genetic susceptibility for sexual dysfunctions. The unique experiences of each individual are, however, the main factors determining if, and which, dysfunction develops.

Evidence for a genetic etiology to ejaculatory dysfunction.

A number of theoretical approaches to understanding the etiology of ejaculatory dysfunction have been proposed, but no study has yet found conclusive evidence that premature (PE) or delayed (DE) ejaculation is under genetic control. We conducted twin model fitting analyses on different indicator variables of ejaculatory function on a population-based sample of 3946 twins and their siblings (age 18-48; mean=29.9 years) to investigate genetic, shared environmental and unique environmental effects on PE and DE. A significant moderate genetic effect (28%) was found for PE. No clear-cut familial effect could be detected for DE. Significant associations between ejaculatory function and age were detected, but effects of age were generally very weak. The findings from the present study provide useful information regarding the etiology and understanding of ejaculatory dysfunction.

Recreational use of erectile dysfunction medication may decrease confidence in ability to gain and hold erections in young males.

We aimed to estimate the frequency of recreational use of erectile dysfunction medication (EDM) and to identify any adverse effects on confidence in gaining and holding erections resulting from such use. In addition, we explored differences in erectile function and sexual behavior between recreational and medicinal users of EDM to control for the possibility of recreational users having but not admitting erectile dysfunction. A subset from the Genetics of Sex and Aggression population-based sample of 4428 males with a mean age of 29.51 (s.d.=6.77) years provided information on their use of EDM, erectile function during first intercourse and currently, sexual behavior and confidence in their ability to gain and hold erections. There were 2.6% (n=115) recreational and 0.9% (n=39) medicinal users of EDM. Recreational users had currently significantly lower confidence in their erectile ability than non-users even though they had significantly better erectile function and significantly more unrestricted sexual behavior as well as had more confidence when initiating sexual activity. More frequent use of EDM was associated with significantly less confidence in erectile ability among the recreational users. We conclude that recreational users of EDM may be vulnerable for becoming psychologically dependent on pharmacologically induced erection.