Association between cannabis use and sexual risk behavior among young heterosexual adults

To study the association between cannabis use and frequent sexual risk behavior, we tested the hypothesis of a situational influence of cannabis use in sexual encounters using a combination of global association study and event-level analysis and examined possible mediator variables, including the personality trait of hedonism/risk preference, psychosocial stress, and HIV-related beliefs, using mediation models. The results of a computer-assisted telephone interview of a random sample of 2790 heterosexual men and women aged 16-24 years showed that risky sexual behavior was more frequent in cannabis-using men and women than in non-using persons. The results did not support a situational effect of cannabis intoxication on sexual risk behavior. The more frequent sexual risk behavior among cannabis users was mediated by decreased intentions to use HIV protection, by lower HIV-self-efficacy, and higher risk preference/hedonism. Only among women psychosocial stress was a partial mediator. The findings show that HIV prevention programs for cannabis-using young adults should emphasize the role of person variables instead of situation variables.

History of offending behavior in first episode psychosis patients: A marker of specific clinical needs and a call for early detection strategies among young offenders

OBJECTIVES Previous literature suggests that early psychosis (EP) patients with a history of offending behavior (HOB) have specific clinical needs. The aims of this study were to assess: (1) the prevalence of HOB in a representative sample of EP; (2) the premorbid and baseline characteristics of patients with HOB, and (3) the potential differences in short-term outcome of such patients when compared to patients without HOB. METHODS The Early Psychosis Prevention and Intervention Centre (EPPIC) admitted 786 EP patients between 1998 and 2000. Data were collected from patients' files using a standardized questionnaire. Data of 647 patients could be analyzed. RESULTS HOB patients (29% of the sample) were more likely to be male with lower level of premorbid functioning and education, have used illicit substances and have attempted suicide. They presented with a more complex clinical picture and had poorer 18-month outcome. Most importantly, they had a significantly longer duration of untreated psychosis. CONCLUSIONS On the basis of the high prevalence and specific features of EP patients with HOB, our study confirms a need for additional research in this domain and for the development of specific treatment strategies. Most importantly, it suggests a need for the promotion of early detection strategies among the populations of young offenders, considering that some of them may be going through the early phases of a psychotic disorder and that reduction of treatment delay and provision of well adapted interventions may have a significant impact at numerous levels in such patients

Analysis of clinical forensic examination reports on sexual assault

Medical-forensic examination of sexual assault victims and alleged offenders is a common task of many forensic institutes. In the current study, the results from samples taken at the Institute of Legal Medicine, Hanover Medical School, during a period from 2005 to 2007 were retrospectively evaluated. In total, 292 victims (283 females and nine males) and 88 suspects were examined. At the time of the assault, 41.8% of the victims and 43.2% of the alleged perpetrators were under the influence of alcohol. Injuries were found in 84.9% of the victims and 39.8% of the suspects. Thirty victims (10.3%) reported having been choked or strangled. Cytology was performed in 218 victims. In 81 cases (38.0%), sperm could be detected in vaginal swabs up to 3 days post-assault. In seven (18.9%) out of 37 anal samples, evidence of sperm could be found 24 h post-assault. None of 22 oral samples was positive for sperm. Out of 301 sexual assault cases, 171 could be proved by means of medical-forensic examination. In summary, our evaluation shows that an early medical-forensic examination of both victim and suspect can secure numerous medical findings. Furthermore, persons intoxicated by alcohol, handicapped persons and persons with psychiatric disorders are more vulnerable to become a sexual assault victim.

Sequential female assessment drives complex sexual selection on bower shape in a cichlid fish

In many animals, sexual selection on male traits results from female mate choice decisions made during a sequence of courtship behaviors. We use a bower-building cichlid fish, Nyassachromis cf. microcephalus, to show how applying standard selection analysis to data on sequential female assessment provides new insights into sexual selection by mate choice. We first show that the cumulative selection differentials confirm previous results suggesting female choice favors males holding large volcano-shaped sand bowers. The sequential assessment analysis reveals these cumulative differentials are the result of selection acting on different bower dimensions during the courtship sequence; females choose to follow males courting from tall bowers, but choose to engage in premating circling with males holding bowers with large diameter platforms. The approach we present extends standard selection analysis by partitioning the variances of increasingly accurate estimates of male reproductive fitness and is applicable to systems in which sequential female assessment drives sexual selection on male traits.

Transmission of Chlamydia trachomatis through sexual partnerships: a comparison between three individual-based models and empirical data

Chlamydia trachomatis is the most common bacterial sexually transmitted infection (STI) in many developed countries. The highest prevalence rates are found among young adults who have frequent partner change rates. Three published individual-based models have incorporated a detailed description of age-specific sexual behaviour in order to quantify the transmission of C. trachomatis in the population and to assess the impact of screening interventions. Owing to varying assumptions about sexual partnership formation and dissolution and the great uncertainty about critical parameters, such models show conflicting results about the impact of preventive interventions. Here, we perform a detailed evaluation of these models by comparing the partnership formation and dissolution dynamics with data from Natsal 2000, a population-based probability sample survey of sexual attitudes and lifestyles in Britain. The data also allow us to describe the dispersion of C. trachomatis infections as a function of sexual behaviour, using the Gini coefficient. We suggest that the Gini coefficient is a useful measure for calibrating infectious disease models that include risk structure and highlight the need to estimate this measure for other STIs.

Asymmetric sexual conflict over parental care in a biparental cichlid

Theoretical models predict that parents should adjust the amount of care both to their own and their partner's body condition. In most biparental species, parental duties are switched repeatedly allowing for repeated mutual adjustment of the amount of care. In the mouthbrooding cichlid Eretmodus cyanostictus, terms are switched only once with females taking the first share. The timing of the shift of the clutch between mates strongly determines both partners' brooding period and thereby their parental investment. Females signal their readiness to transfer the young several days before the male finally takes them, suggesting sexual conflict over the timing of the shift. In a lab experiment, we reduced the body condition of either the female or the male of a pair to test whether energy reserves affect the timing of the shift and whether female signalling behaviour depends on energetic state. Males with a lowered condition took the young later and incubated for a shorter period, which prolonged the incubation time of their female partners. When female condition was lowered, female and male incubation durations remained unchanged, although females signalled their readiness to shift more intensely. Our results suggest that males adjust their parental investment to own energy reserves but are unresponsive to their mate's condition. Females appear to carry the entire costs for the male's adjustment of care. We propose that intrinsic asymmetries in the scope for mutual adjustment of parental investment and the costs of negotiation crucially influence solutions of the conflict between sexes over care.

Sexual dysfunction in multiple sclerosis

Multiple sclerosis is a chronic disease that commonly affects young adults who may be sexually active. Sexual dysfunction is a significant, but often underestimated, symptom of multiple sclerosis, affecting 50-90% of men and 40-80% of women. The types of sexual dysfunction can be categorized in terms of the normal sexual response cycle: sexual interest/desire dysfunction (reduced libido), sexual arousal dysfunction (including erectile dysfunction) and ejaculatory and orgasmic dysfunction. Sexual dysfunction may not only be due to lesions affecting the neural pathways involved in physiological function (primary dysfunction), but also result from general physical disabilities (secondary dysfunction) or psychological and emotional issues (tertiary dysfunction). Comprehensive management should address all these possible contributing problems. Specific pharmacotherapy is only currently available for erectile dysfunction. This review summarizes the available information about sexual dysfunction in men and women with multiple sclerosis.

Social Factors Associated with Readiness for Sexual Activity in Adolescents: A Population-Based Cohort Study

Various factors are associated with sexual activity in adolescence and it is important to identify those that promote healthy and adaptive romantic and sexual development. The objectives of this study were to describe rates of early sexual intercourse (before 16 years) and sexual readiness in adolescence and to assess the extent to which these were social patterned. We prospectively studied nearly 5,000 15-year-olds from the Avon Longitudinal Study of Parents and Children, a UK birth cohort. Between 2006 and 2008, female and male participants answered a computer assisted interview about romantic and sexual behaviors in the last year. Predictors of sexual intercourse and readiness for sexual intercourse were examined across a range of sociodemographic measures. Overall, 17.7 % (95 % CI 16.7 %, 18.9 %) of participants reported having had sexual intercourse in the last year, with more girls than boys reporting sexual experience (risk ratio 1.30, 95 % CI 1.15, 1.47). Of these, one-third of both male and female were classed as unready because they were unwilling, lacking in autonomy, felt regret or had not used contraception. There was strong evidence of social patterning for sexual activity with higher rates for young people from poorer homes, with lower social class, and with younger, less educated mothers. In contrast, among 860 young people who had had sexual intercourse, there was no clear evidence of associations between social factors and sexual readiness. The lack of social patterning in sexual readiness supports the provision of comprehensive education to develop life skills for adolescents across all social groups.

Chlamydia prevalence in young attenders of rural and regional primary care services in Australia: a cross-sectional survey.

OBJECTIVE To estimate chlamydia prevalence among 16-29-year-olds attending general practice clinics in Australia. DESIGN, PARTICIPANTS AND SETTING A cross-sectional survey was conducted from May 2010 to December 2012. Sexually experienced 16-29-year-olds were recruited from 134 general practice clinics in 54 rural and regional towns in four states and in nine metropolitan clinics (consecutive patients were invited to participate). Participants completed a questionnaire and were tested for chlamydia. MAIN OUTCOME MEASURE Chlamydia prevalence. RESULTS Of 4284 participants, 197 tested positive for chlamydia (4.6%; 95% CI, 3.9%-5.3%). Prevalence was similar in men (5.2% [65/1257]; 95% CI, 3.9%-6.4%) and women (4.4% [132/3027]; 95% CI, 3.5%-5.2%) (P = 0.25) and high in those reporting genital symptoms or a partner with a sexually transmissible infection (STI) - 17.0% in men (8/47; 95% CI, 2.8%-31.2%); 9.5% in women (16/169; 95% CI, 5.1%-13.8%). Nearly three-quarters of cases (73.4% [130/177]) were diagnosed in asymptomatic patients attending for non-sexual health reasons, and 83.8% of all participants (3258/3890) had attended for non-sexual health reasons. Prevalence was slightly higher in participants from rural and regional areas (4.8% [179/3724]; 95% CI, 4.0%-5.6%) than those from metropolitan areas (3.1% [17/548]; 95% CI, 1.5%-4.7%) (P = 0.08). In multivariable analysis, increasing partner numbers in previous 12 months (adjusted odds ratio [AOR] for three or more partners, 5.11 [95% CI, 2.35-11.08]), chlamydia diagnosis in previous 12 months (AOR, 4.35 [95% CI, 1.52-12.41]) and inconsistent condom use with most recent partner (AOR, 2.90 [95% CI, 1.31-6.40]) were significantly associated with chlamydia in men. In women, increasing partner numbers in previous 12 months (AOR for two partners, 2.59 [95% CI, 1.59-4.23]; AOR for three or more partners, 3.58 [95% CI, 2.26-5.68]), chlamydia diagnosis in previous 12 months (AOR, 3.13 [95% CI, 1.62-6.06]) and age (AOR for 25-29-year-olds, 0.23 [95% CI, 0.12-0.44]) were associated with chlamydia. CONCLUSIONS Chlamydia prevalence is similar in young men and women attending general practice. Testing only those with genital symptoms or a partner with an STI would have missed three-quarters of cases. Most men and women are amenable to being tested in general practice, even in rural and regional areas.

Comparing growth trajectories of risk behaviors from late adolescence through young adulthood: An accelerated design

Risk behaviors such as substance use or deviance are often limited to the early stages of the life course. Whereas the onset of risk behavior is well studied, less is currently known about the decline and timing of cessation of risk behaviors of different domains during young adulthood. Prevalence and longitudinal developmental patterning of alcohol use, drinking to the point of drunkenness, smoking, cannabis use, deviance, and HIV-related sexual risk behavior were compared in a Swiss community sample (N = 2,843). Using a longitudinal cohort-sequential approach to link multiple assessments with 3 waves of data for each individual, the studied period spanned the ages of 16 to 29 years. Although smoking had a higher prevalence, both smoking and drinking up to the point of drunkenness followed an inverted U-shaped curve. Alcohol consumption was also best described by a quadratic model, though largely stable at a high level through the late 20s. Sexual risk behavior increased slowly from age 16 to age 22 and then remained largely stable. In contrast, cannabis use and deviance linearly declined from age 16 to age 29. Young men were at higher risk for all behaviors than were young women, but apart from deviance, patterning over time was similar for both sexes. Results about the timing of increase and decline as well as differences between risk behaviors may inform tailored prevention programs during the transition from late adolescence to adulthood.