Contribution of sex hormones to gender differences in schizophrenia: A review

Sexual activity and respiratory disease: A systematic review

CONTEXT

Sex and gender are related concepts, but they have distinct meanings and implications. Respiratory diseases are a major driver of morbi-mortality. It is frequent that respirologists, primary care doctors, or other specialists, when dealing with respiratory patients, and aiming for a holistic management of their patients, they all skip any question or matter associated with sexual activity or behavior.

OBJECTIVES

To review how sexual activity is explored in respiratory patients.

METHODS

To conduct this review, we endorse PRISMA guidance for reporting systematic reviews, and also the sex and gender equity in research (SAGER) guidelines.

RESULTS

Compared to other conditions such as heart disease, mental disorders, Alzheimer's, or even COVID-19, to date there is no review focused on sexual activity and respiratory health and disease. Asthma, COPD and other respiratory patients can have their sexual activity and behaviors affected by their disease, but also limitations in sex might be the sentinel event of an incident respiratory disease. Asking on sexual desire and related sex issues should not be considered taboo in any respiratory consultation. Importantly, any marketed stereotypes on cigarettes after any sexual activity should be counteracted. Many clinical trials of respiratory drugs keep recruiting few or no women, so research on women's sexual desire and satisfaction lags behind that of men's. By using the available objective tools and validated questionnaires summarized in this review, these important domains of respiratory patients and their partners can be properly identified and managed.

CONCLUSIONS

Sexual activity, depending on age and individual specific conditions, is a fundamental driver of overall health, and therefore of lung health.

Sex and gender correlates of sexually polymorphic cognition

BACKGROUND

Sexually polymorphic cognition (SPC) results from the interaction between biological (birth-assigned sex (BAS), sex hormones) and socio-cultural (gender identity, gender roles, sexual orientation) factors. The literature remains quite mixed regarding the magnitude of the effects of these variables. This project used a battery of classic cognitive tests designed to assess the influence of sex hormones on cognitive performance. At the same time, we aimed to assess the inter-related and respective effects that BAS, sex hormones, and gender-related factors have on SPC.

METHODS

We recruited 222 adults who completed eight cognitive tasks that assessed a variety of cognitive domains during a 150-min session. Subgroups were separated based on gender identity and sexual orientation and recruited as follows: cisgender heterosexual men (n = 46), cisgender non-heterosexual men (n = 36), cisgender heterosexual women (n = 36), cisgender non-heterosexual women (n = 38), gender diverse (n = 66). Saliva samples were collected before, during, and after the test to assess testosterone, estradiol, progesterone, cortisol, and dehydroepiandrosterone. Psychosocial variables were derived from self-report questionnaires.

RESULTS

Cognitive performance reflects sex and gender differences that are partially consistent with the literature. Interestingly, biological factors seem to better explain differences in male-typed cognitive tasks (i.e., spatial), while psychosocial factors seem to better explain differences in female-typed cognitive tasks (i.e., verbal).

CONCLUSION

Our results establish a better comprehension of SPC over and above the effects of BAS as a binary variable. We highlight the importance of treating sex as a biological factor and gender as a socio-cultural factor together since they collectively influence SPC.

Estradiol driven change in hallucination proneness across the menstrual cycle as studied with a white noise paradigm

The estrogen hypothesis for schizophrenia suggests neuroprotective effects of estrogen for the development of the disorder and for symptom severity, including auditory hallucinations. Furthermore, estrogen has shown enhancing effects on cognitive control, a function that is also implicated in auditory hallucinations. Whether estrogen affects the tendency to hallucinate in healthy participants, and the potential mediating role of cognitive control, has not yet been studied. Therefore, the current study aimed to test these relationships by using a white noise paradigm in combination with a N-back working memory task in which cognitive load could be manipulated. The paradigm used simulates a hallucinatory state by induction of negative emotions and drainage of cognitive resources. The simultaneous exposure to white noise elicit experiences of hearing voices (false alarms). In a between-subject design, forty-two participants were tested during the menstrual cycle in either the early follicular phase (low estradiol) or late follicular phase (high estradiol). A 2(Cycle Phase) x2(N-back task) ANOVA showed a main-effect of cycle phase on number of experienced hallucinations in the white noise task, with a significantly higher number of reported hallucinations in the early follicular phase. Furthermore, estradiol was found to predict number of hallucinations. No interaction effect of cycle phase and available cognitive resources was found. The results suggest an estradiol-related change in hallucination proneness across the menstrual cycle, but the idea that cognitive functioning mediates this relationship was not supported. Overall, the study supports protective effects of estradiol on hallucination proneness in line with the estrogen-hypothesis of schizophrenia, and that such effects are not specific to the disease.

Brain-derived neurotrophic factor, sex hormones and cognitive decline in male patients with schizophrenia receiving continuous antipsychotic therapy

BACKGROUND

There are systematic differences in clinical features between women and men with schizophrenia (SCZ). The regulation of sex hormones may play a potential role in abnormal neurodevelopment in SCZ. Brain-derived neurotrophic factor (BDNF) and sex hormones have complex interacting actions that contribute to the etiology of SCZ.

AIM

To investigate the influence of BDNF and sex hormones on cognition and clinical symptomatology in chronic antipsychotic-treated male SCZ patients.

METHODS

The serum levels of follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), progesterone, testosterone (T), prolactin (PRL) and BDNF were compared between chronic antipsychotic-treated male (CATM) patients with SCZ (n = 120) and healthy controls (n = 120). The Positive and Negative Syndrome Scale was used to quantify SCZ symptoms, while neuropsychological tests were used to assess cognition. Neuropsychological tests, such as the Digit Cancellation Test (DCT), Semantic Verbal Fluency (SVF), Spatial Span Test (SS), Paced Auditory Serial Addition Test (PASAT), Trail Making Task (TMT-A), and Block Design Test (BDT), were used to assess executive functions (BDT), attention (DCT, TMT-A), memory (SS, PASAT), and verbal proficiency (SVF).

RESULTS

Although E2 levels were significantly lower in the patient group compared to the healthy controls, T, PRL, and LH levels were all significantly higher. Additionally, the analysis revealed that across the entire sample, there were positive correlations between E2 Levels and BDNF levels as well as BDNF levels and the digital cancellation time. In CATM patients with SCZ, a significant correlation between the negative symptoms score and PRL levels was observed.

CONCLUSION

Sex hormones and BDNF levels may also be linked to cognitive function in patients with chronic SCZ.

The relationship between sex and functional outcome in first-episode schizophrenia: the role of premorbid adjustment and insight

BACKGROUND

Studies that examined sex differences in first-episode patients consistently show that males compared to females have poor premorbid adjustment, earlier age of onset, worse clinical characteristics, and poorer outcomes. However, little is known about potential mediators that could explain these sex differences.

METHODS

Our sample consisted of 137 individuals with first episode schizophrenia (males, n = 105; 77%) with a mean age of 22.1(s.d. = 4.1) years and mean education of 12.5(s.d. = 1.7) years. At entry, patients were within 2 years of their first psychotic episode onset. Baseline assessments were conducted for premorbid adjustment, symptoms, cognitive functioning, insight, and at 6-months for role and social functioning.

RESULTS

Males as compared to females had poorer premorbid adjustment across several key developmental periods (p < 0.01), an earlier age of onset [M = 20.3(3.3) v. 22.8(5.6), p = 0.002], more negative symptoms (p = 0.044), poorer insight (p = 0.031), and poorer baseline and 6-month role (p = 0.002) and social functioning (p = 0.034). Several of these variables in which males showed impairment were significant predictors of 6-month role and social functioning. Premorbid adjustment and insight mediated the relationship between sex and role and social functioning at 6-months, but not negative symptoms.

DISCUSSION

Males compared to females were at lower levels across several key premorbid and clinical domains which are strongly associated with functional outcome supporting the hypothesis that males might have a more disabling form of schizophrenia. The relationship between sex with role and social functioning was mediated through premorbid adjustment and insight suggesting pathways for understanding why females might have a less disabling form of schizophrenia.

Gender differences in prevalence and associated factors of metabolic syndrome in first-treatment and drug-naïve schizophrenia patients

BACKGROUND

Metabolic syndromes (MetS) are clinical syndromes involving multiple pathological states with distinct gender-specific clinical patterns. As a serious disorder associated with psychiatric conditions, the prevalence of MetS is significantly higher in the population with schizophrenia (Sch). The aim of this paper is to report gender differences in the prevalence, associated factors and severity-related factors of MetS in first-treatment and drug-naïve (FTDN) patients with Sch.

METHODS

A total of 668 patients with FTDN Sch were included in this study. We collected socio-demographic and general clinical information on the target population, measured and evaluated common metabolic parameters and routine biochemical indicators, and assessed the severity of psychiatric symptoms using Positive and Negative Symptom Scale (PANSS).

RESULTS

In the target group, the prevalence of MetS was significantly higher in women (13.44%, 57/424) than in men (6.56%, 16/244). In the males, waist circumference (WC), fasting blood glucose (FBG), diastolic blood pressure (DBP), and triglycerides (TG) were risk factors for MetS, while systolic blood pressure (SBP), TG, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and platelet (PLT) were risk factors for the females. More importantly, for the females, we found that age, LDL-C, PANSS scores and blood creatinine (CRE) were risk factors for higher MetS scores, while onset age and hemoglobin (HGB) were protective factors.

CONCLUSION

There are significant gender differences in the prevalence of MetS and its factors among patients with FTDN Sch. The prevalence of MetS is higher and the factors that influence MetS are more numerous and extensive in females. The mechanisms of this difference need further research and clinical intervention strategies should be formulated with gender differences.

The global burden of schizophrenia and the impact of urbanization during 1990-2019: An analysis of the global burden of disease study 2019

BACKGROUND AND HYPOTHESIS

The burden of schizophrenia is increasing. Assessing the global distribution of schizophrenia and understanding the association between urbanization factors and schizophrenia are crucial.

STUDY DESIGN

We conducted a two-stage analysis utilizing public data from GBD (global burden of disease) 2019 and the World Bank. First, the distribution of schizophrenia burden at the global, regional, and national levels as well as temporal trends was analyzed. Then, four composite indicators of urbanization (including demographic, spatial, economic, and eco-environment urbanization) were constructed from ten basic indicators. Panel data models were used to explore the relationship between urbanization indicators and the burden of schizophrenia.

RESULTS

In 2019, there were 23.6 million people with schizophrenia, an increase of 65.85% from 1990, and the country with the largest ASDR (age-standardized disability adjusted life years rate) was the United States of America, followed by Australia, and New Zealand. Globally, the ASDR of schizophrenia rose with the sociodemographic index (SDI). In addition, six basic urbanization indicators including urban population proportion, employment in industry/services proportion, urban population density, the population proportion in the largest city, GDP, and PM_2.5 concentration were positively associated with ASDR of schizophrenia, with the largest coefficients being urban population density. Overall, demographic, spatial, economic, and eco-environment urbanization all had positive effects on schizophrenia, and the estimated coefficients indicated that demographic urbanization was the most significant influence.

CONCLUSIONS

This study provided a comprehensive description of the global burden of schizophrenia and explored urbanization as a factor contributing to the variation in the burden of schizophrenia, and highlighted policy priorities for schizophrenia prevention in the context of urbanization.

Sex differences in symptomatology in people with schizophrenia and other psychotic disorders: protocol for a systematic review and pairwise meta-analysis of observational studies

Sex differences in symptomatology in people with psychosis have been studied extensively in recent decades. Although studies have pointed to such differences, to date there is no review that has performed a systematic search and quantitative synthesis. In this paper, we describe the protocol for a pairwise meta-analysis comparing a range of symptom outcome measures between men and women diagnosed with a psychotic spectrum disorder at different stages of the disorder (PROSPERO registration number CRD42021264942). In August 2021 we conducted systematic searches of PsychInfo, PubMed, Web of Science, Scopus and Dialnet to identify observational studies that report data on symptoms for males and females separately. Two independent reviewers will conduct literature searches, select studies, extract data, assess the risk of bias and assess outcome quality. To assess the effect size of all outcome measures, we will conduct pairwise meta-analysis using random-effects models. The quality of studies will be evaluated using a National Heart, Lung and Blood Institute's quality assessment tool and the confidence in the results will be evaluated using the GRADE tool. Meta-regression and sensitivity analyses will be conducted to assess the robustness of the findings. No ethical problems are foreseen. Results from this study will be published in peer-reviewed journals and presented at relevant conferences.

In-depth investigations of the molecular basis underlying sex differences among middle-aged and elderly schizophrenia populations

Sex can influence almost all aspects of schizophrenia. However, the molecular mechanisms underlying sex differences in schizophrenia remain poorly understood. In this project, the dataset GSE107638 containing neuronal RNA-seq data and age/sex information of individuals with or without schizophrenia were retrieved. Schizophrenia samples were divided into young male (M-1), young female (F-1), middle-aged and elderly male (M-2) and middle-aged and elderly female (F-2) groups. Next, green/yellow/turquoise modules related to the M-2 trait and turquoise module correlated with the F-2 trait were identified by weighted correlation network analysis (WGCNA) analysis (soft thresholding power: 13; min module size: 200). Crucial genes in the M-2 green, M-2 turquoise and F-2 turquoise modules were identified by WGCNA, gene significance/module membership, and protein-protein interaction (PPI) analysis. Moreover, 2067 and 934 differentially expressed genes (|log2 fold-change| ≥0.58 and P-value < 0.05) in M-2 and F-2 schizophrenia subgroups versus same-age and same-sex counterparts were identified, respectively. Additionally, 82 core genes in the M-2 turquoise module and 4 hub genes in the F-2 turquoise module were differentially expressed in M-2 and F-2 schizophrenia subgroups versus their counterparts, respectively. Among the 82 hub genes, 15 genes were found to be correlated with neuronal development by the Kyoto Encyclopedia of Genes and Genomes enrichment analysis. Also, 2 potential PPI networks related to neuronal development were identified. Taken together, multiple potential hub genes and 2 potential neurobiological networks related to schizophrenia sex differences and disease progression were identified among middle-aged and elderly schizophrenia populations.

Antipsychotic medication for women with schizophrenia spectrum disorders

There are significant differences between men and women in the efficacy and tolerability of antipsychotic drugs. Here, we provide a comprehensive overview of what is currently known about the pharmacokinetics and pharmacodynamics of antipsychotics in women with schizophrenia spectrum disorders (SSDs) and translate these insights into considerations for clinical practice. Slower drug absorption, metabolism and excretion in women all lead to higher plasma levels, which increase the risk for side-effects. Moreover, women reach higher dopamine receptor occupancy compared to men at similar serum levels, since oestrogens increase dopamine sensitivity. As current treatment guidelines are based on studies predominantly conducted in men, women are likely to be overmedicated by default. The risk of overmedicating generally increases when sex hormone levels are high (e.g. during ovulation and gestation), whereas higher doses may be required during low-hormonal phases (e.g. during menstruation and menopause). For premenopausal women, with the exceptions of quetiapine and lurasidone, doses of antipsychotics should be lower with largest adjustments required for olanzapine. Clinicians should be wary of side-effects that are particularly harmful in women, such as hyperprolactinaemia which can cause oestrogen deficiency and metabolic symptoms that may cause cardiovascular diseases. Given the protective effects of oestrogens on the course of SSD, oestrogen replacement therapy should be considered for postmenopausal patients, who are more vulnerable to side-effects and yet require higher dosages of most antipsychotics to reach similar efficacy. In conclusion, there is a need for tailored, female-specific prescription guidelines, which take into account adjustments required across different phases of life.

“Suffering as a Lifelong Companion: A Phenomenological-Hermeneutic Study of Men Living With Severe Psychiatric Illness”Lidelse som livslang følgesvenn: En fenomenologisk-hermeneutisk studie av menn som lever med alvorlig psykiatrisk sykdom

Accumulation of suffering in later life due to severe psychiatric illness has received surprisingly little interest in nursing research. Suffering in daily living seems to be more demanding for men, a phenomenon still debated in the literature. This phenomenological-hermeneutic study aims at describing and interpreting the perspectives of adult men and their experiences of suffering in daily living with severe psychiatric illness, diagnosed as schizophrenia. Data were collected in dialogical conversations with four men aged between 20 and 40 years, living alone in northern Norway. The themes created from the structural understanding illuminate the participants’ suffering as simultaneously struggling against the grasp of the illness and for reshaping the future. The theoretical interpretation unfolds the multidimensionality of their suffering and the need for confirmation of the suffering and reconciliation with the losses from illness, thus making reorientation to the future possible.

Sex Difference in Comorbid Depression in First-Episode and Drug-Naive Patients With Schizophrenia: Baseline Results From the Depression in Schizophrenia in China Study

OBJECTIVE

Comorbid depression is common in schizophrenia, and sex differences are prominent in many aspects of schizophrenia. However, few studies have investigated sex difference in comorbid depression in schizophrenia. This large sample study aimed to investigate sex differences in first-episode drug-naive (FEDN) patients with schizophrenia comorbid major depressive episode (SZ-MDE).

METHODS

A total of 996 FEDN patients with schizophrenia (472 males/524 females) were recruited. The 17-item Hamilton Depression Rating Scale and Positive and Negative Syndrome Scale (PANSS) were applied.

RESULTS

There was no difference in the prevalence of comorbid MDE between male and female patients with schizophrenia. Among SZ-MDE patients, men had more severe psychotic symptoms (scores of PANSS total scale, negative scale, and general psychopathology scale), more severe depressive symptoms, and higher proportion of severe depression than women (all p < .001). The early onset age of schizophrenia, smoking, and PANSS positive score were the risk factors for comorbid MDE only in female patients with schizophrenia (all p < .05). Furthermore, in female patients with SZ-MDE, smoking was associated with the severity category of depression (p = .001, odds ratio = 2.70). Multiple variable regression demonstrated that the Hamilton Depression Rating Scale score correlated with PANSS general psychopathology (p = .01) and total scores (p = .04) in female SZ-MDE.

CONCLUSIONS

Our results indicate sex differences in proportion of severe depression, clinical symptoms, and factors of comorbid MDE in FEDN patients with schizophrenia. These sex differences have clinical implications for the treatment of depression as related to the nature and severity of psychopathological symptoms in patients with schizophrenia.

Stratification by Sex and Hormone Level When Contrasting Men and Women in Schizophrenia Trials Will Improve Personalized Treatment

BACKGROUND

Sex and gender differences have been reported in the prevalence, expression, treatment response, and outcome of schizophrenia, but most reports are based on relatively small samples that have not been stratified for the impact of sex hormone levels. This literature review aims to show how women's hormone levels can impact the results of male/female comparisons.

METHODS

This is a narrative review of data from publications of the last decade.

RESULTS

Epidemiologic evidence, reports of the impact of hormones on cognition, results of sexually dimorphic responses to treatment, and male/female trajectories of illness over time all suggest that female hormone fluctuations exert major effects on male/female differences in schizophrenia.

CONCLUSIONS

Information on hormonal status in women participants is rarely available in clinical studies in schizophrenia, which makes male/female comparisons largely uninterpretable. These are the current challenges. Opportunities for individualized treatment are growing, however, and will undoubtedly result in improved outcomes for both women and men in the future.

The co-occurrence of autistic spectrum disorder and schizophrenia: A nationwide population-based study

Although the co-occurrence of autistic spectrum disorder (ASD) and schizophrenia have been previously reported, the scope and magnitude of this comorbidity across large samples have not been sufficiently established. This study was aimed to assess the co-occurrence between schizophrenia and ASD in a large dataset, and to examine its predominance across different age and sex groups. Schizophrenia patients and age and sex frequency controls (n = 49,334) were assessed for the prevalence of autism spectrum disorder. The sample was stratified by age and sex, and co-occurrence was assessed using univariate and multivariate logistic regressions. Results indicated that schizophrenia was associated with ASD (OR = 7.01, 95%CI 2.98-16.43, p < .0001) across all age groups aside from 50 to 70 years. This association was significant among male participants (OR = 11.69, 95%CI 3.59-38.01, p < .0001) but not among female participants (OR = 2.33, 95%CI 0.60-9.03, p = .21). These findings indicate a large overlap between schizophrenia and ASD, and point to the need to expand the understanding of the potential mediating mechanisms of this co-occurrence.

Estrogens in schizophrenia: progress, current challenges and opportunities

PURPOSE OF REVIEW

Schizophrenia is a heterogeneous psychiatric disorder with a different, but not necessarily milder clinical presentation in women as compared to men. These sex differences have largely been attributed to the protective role of estrogens. This article reviews the current state of estrogen research in schizophrenia.

RECENT FINDINGS

Estrogens regulate important pathophysiological pathways in schizophrenia, including dopamine activity, mitochondrial function, and the stress system. Estrogen deficiency is common in both sexes and is associated with increases in psychotic symptoms. Hyperprolactinemia causes secondary estrogen deficiency and can be a reaction to stress, or secondary to prolactin-raising antipsychotics. Therefore, prolactin-sparing antipsychotics should be preferred especially in premenopausal women, who are more prone to hyperprolactinemia. Premenopausal women furthermore require lower doses of antipsychotics than men, since estrogens raise the availability and efficacy of antipsychotics.

SUMMARY

The past years have established the importance of estrogens in the pathophysiology of schizophrenia and have shown its relevance to clinical practice through its influence on antipsychotic drug efficacy. Future research should focus on the neurobiological and clinical effect of contraceptives in premenopausal women with schizophrenia. Furthermore, the potential of estrogen-like augmentation with raloxifene and phytoestrogens in schizophrenia should be established in the coming years.

Clozapine tolerability in Treatment Resistant Schizophrenia: exploring the role of sex

Clozapine is the only evidence-based drug indicated for Treatment Resistant Schizophrenia but it is largely underprescribed, partially due to its life-threatening adverse effects (AEs). However, clozapine treatment is burdened by other common AEs as constipation, hypersalivation, postural hypotension, tachycardia and metabolic abnormalities. Few studies have investigated sex-related differences in clozapine's tolerability, reporting women to experience more frequently weight gain, hyperglycemia and constipation, while men hypertension and dyslipidemia. Based on these premises, we investigated clinical, psychopathological and metabolic sex-related differences among 147 treatment-resistant patients treated with clozapine, with a specific focus on non-life-threatening AEs. We observed significant higher prevalence of tachycardia in men, and of orthostatic hypotension and constipation in women. Concerning metabolic alterations, we observed significant lower levels of HDL-cholesterol and higher prevalence of hypertriglyceridemia among men, whereas females showed higher prevalence of abdominal obesity. Consistently with previous studies, our data confirm the presence of sex-related differences in clozapine tolerability, with a main effect of sex especially for tachycardia, postural hypotension and constipation. Although non-life-threatening, these common AEs significantly affect patients' quality of life, undermine compliance and cause treatment discontinuation. A better understanding of this topic could contribute to tailor therapeutic approaches, thus improving tolerability, compliance and clinical stability.

Sexual Dysfunction in Chronically Medicated Male Inpatients With Schizophrenia: Prevalence, Risk Factors, Clinical Manifestations, and Response to Sexual Arousal

BACKGROUND

Sexual dysfunction is a common symptom in patients with schizophrenia, especially in chronically medicated patients. However, the relationship between sexual dysfunction and emotional response to sexual arousal in male patients with schizophrenia remains unclear. This study aimed to assess the incidence, risk factors of sexual dysfunction in males, and their clinical correlations to sexual arousal in male patients with schizophrenia in China.

METHODS

A total of 162 male patients, aged 18-50 years, with schizophrenia were recruited from a psychiatric hospital in Ganzhou. The clinical symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS). The Arizona Sexual Experience Scale was utilized to evaluate sexual dysfunction. Erotic images were selected from International Affective Picture System (IAPS). Sixty-eight out of the 162 subjects completed the erotic pictures reactivity task.

RESULTS

Overall, 48 (29.6%) patients were measured as having global sexual dysfunction, 72 (44.4%) patients as having strength of sex drive dysfunction, 51 (31.5%) patients as having sexual arousal dysfunction, 55 (34.0%) patients as having penile erection dysfunction, 60 (37.0%) patients as having reached orgasm dysfunction, and 60 (37.0%) patients as having satisfaction with orgasm dysfunction. The sexual dysfunction patients had significantly higher scores on the negative symptoms of the PANSS. The only important predictor of sexual dysfunction was the severity of PANSS negative factor. The sense of pleasure and arousal post viewing erotic images in the sexual dysfunction group were lower compared to the non-sexual dysfunction group. The sense of pleasure and approach motivation were significantly negatively correlated with the severity of sexual dysfunction.

CONCLUSIONS

This study shows that nearly one-third of young and middle-aged chronically medicated male inpatients with schizophrenia suffer from sexual dysfunction. The negative factor of the PANSS can be regarded as the risk factor of sexual dysfunction. Schizophrenia patients with sexual dysfunction experienced lower pleasure and higher avoidance motivation than non-sexual dysfunction patients when exposed to erotic stimuli.

The Role of Estrogen Receptors and Their Signaling across Psychiatric Disorders

Increasing evidence suggests estrogen and estrogen signaling pathway disturbances across psychiatric disorders. Estrogens are not only crucial in sexual maturation and reproduction but are also highly involved in a wide range of brain functions, such as cognition, memory, neurodevelopment, and neuroplasticity. To add more, the recent findings of its neuroprotective and anti-inflammatory effects have grown interested in investigating its potential therapeutic use to psychiatric disorders. In this review, we analyze the emerging literature on estrogen receptors and psychiatric disorders in cellular, preclinical, and clinical studies. Specifically, we discuss the contribution of estrogen receptor and estrogen signaling to cognition and neuroprotection via mediating multiple neural systems, such as dopaminergic, serotonergic, and glutamatergic systems. Then, we assess their disruptions and their potential implications for pathophysiologies in psychiatric disorders. Further, in this review, current treatment strategies involving estrogen and estrogen signaling are evaluated to suggest a future direction in identifying novel treatment strategies in psychiatric disorders.

Examining which factors influence age of onset in males and females with schizophrenia

OBJECTIVE

Data from the 2010 Australian National Survey of High Impact Psychosis (SHIP) was used to examine (1) what variables influence age of onset (AOO) for males and females, and (2) whether influencing variables were different between the sexes.

METHOD

Data from 622 schizophrenia patients in the SHIP sample was used. These included early life factors, encompassing family psychiatric history, childhood development, trauma and parental loss. Factors occurring within 12 months of diagnosis were also used, including drug/alcohol abuse and premorbid work and social adjustment. Based on the recognised differences in symptom profiles and AOO between the sexes, these factors were regressed separately for males and females.

RESULTS

Stepwise linear regressions showed that a family history of psychiatric disorders was significantly associated with earlier AOO in both sexes. Other variables differed between males and females. Specifically, for females, an earlier AOO was associated with poor premorbid social adjustment and the loss of a family member in childhood. Older AOO was associated with immigrant status. For males, a younger AOO was associated with unemployment at onset, poor premorbid work adjustment, parental divorce in childhood, and lifetime cannabis use. A higher premorbid IQ was associated with an older AOO.

CONCLUSION

Familial predisposition to psychiatric illness is related to earlier AOO of schizophrenia independent of sex. Males appear to have more individual-based predictive factors while females seem to have more community/social-based influences. Future directions for research in schizophrenia are suggested.

Sex hormone levels in drug-naïve, first-episode patients with psychosis

Aim: Sex differences have long been reported in schizophrenia leading to the hypothesis that sex hormones may be implicated in the pathophysiology of the disorder. We assessed gonadal hormones during the fasted state in drug-naïve patients with psychosis.Method: Fasting serum concentrations of follicular-stimulating hormone (FSH) and luteinizing hormone (LH), testosterone, free-testosterone, Sex Hormone Binding Globulin (SHBG) and oestradiol (E₂) were compared between a group of 55 newly diagnosed, drug-naïve, first-episode men with psychosis and a group of 55 healthy controls, matched for age, smoking status and BMI. Testosterone, free-testosterone and SHBG were compared between a group of 32 drug-naïve, first-episode females with psychosis and a group of 32 healthy controls matched for age, smoking status and BMI.Results: Testosterone and free-testosterone levels were significantly lower in the patients' group and SHBG levels significantly higher in the patients' group compared to those in healthy controls. The two female groups had similar values in the hormones which were measured.Conclusion: Our findings provide evidence of lower testosterone and free-testosterone levels and increased SHBG levels in drug-naïve, first-episode males with psychosis.KEY POINTSReduced testosterone and free-testosterone levels in drug-naive, first-episode males with psychosis.Increased SHBG levels in drug-naive first-episode males with psychosis.No difference in FSH, LH and E2 levels between drug-naive first episode males with psychosis and controls.No difference in testosterone, free-testosterone and SHBG levels between drug-naive, first-episode women with psychosis and controls.

Quantitative analysis of underivatized 17 β-estradiol using a high-throughput LC-MS/MS assay - Application to support a pharmacokinetic study in ovariectomized guinea pigs

Difference in female sex hormone, β-estradiol (E₂), levels can contribute to sex differences in biological processes that underlie target tissue functions (QT interval), vulnerability to diseases (hepatitis or HIV), and response toward therapies. Accurate quantification of plasma E₂ level is thus an important aspect in both basic science research examining hormone-regulated physiological mechanisms and in clinical settings to support patient care associated with altered E₂ levels. Due to lack of a high-throughput high-sensitivity analytical method, we developed and validated a LC-MS/MS assay for accurate low-level quantification of E₂ and demonstrated its application to a guinea pig pharmacokinetic study in which guinea pigs were treated with 10 or 40 μg/kg E₂ subcutaneously and blood samples collected at 0 (pre-dose), 0.25, 0.5, 1, 2, 4, 8, 12 and 24 h post-dosing. E₂ was extracted using 90 μL ovariectomized guinea pig plasma by liquid-liquid extraction. The method was robust, sensitive with linear range from 3.9 to 1000 pg/mL, and the assay met acceptance criteria for validation parameters listed in the current FDA Guidance on Bioanalytical Method Validation. Compared to the 10 μg/kg dose, more than dose proportional increase in maximum E₂ plasma concentration (C_max) and AUC_0-∞ and correspondingly longer half-life were observed after 40 μg/kg dose. This assay is a significant improvement over existing E₂ quantification methods in bioanalytical field, with high precision and accuracy, low sample and injection volumes, no derivatization, and short assay run time of 3 min. This assay is amenable in high-throughput settings requiring low-level E₂ quantitation in basic science research and clinical settings.

Cortisol and DHEAS Related to Metabolic Syndrome in Patients with Schizophrenia

BACKGROUND

Both dehydroepiandrosterone (DHEAS) and cortisol are secreted by the adrenal glands and may modulate metabolic syndrome (MetS), which often affects the health of patients with schizophrenia. The relationship between the serum levels of these hormones and MetS has not been established.

PURPOSE

In this pilot study, we investigated the serum levels in schizophrenia patients with and without MetS and compared them with those in healthy volunteers.

PATIENTS AND METHODS

After obtaining informed consent, 110 patients with acute paranoid schizophrenia were recruited directly after admission to the Mental Health Research Institute. The control group consisted of 51 persons reported on questioning to be mentally and somatically healthy. Blood samples to prepare serum were drawn after an 8-h overnight fast during one of the first days of admission. Serum cortisol and DHEAS concentrations were quantified by enzyme-linked immunosorbent assay.

RESULTS

A total of 42 patients had MetS and 68 patients were without MetS. The cortisol blood level was significantly (p = 0.012) higher in schizophrenia patients without MetS in comparison to healthy controls, while patients with schizophrenia and a MetS have significantly (p = 0.014) lower DHEAS levels than healthy volunteers. These differences could, however, exclusively be attributed to female participants. Analysis of covariance adjusted for gender and age demonstrated a significant relationship between age and DHEAS levels (F = 9.512, р = 0.003).

CONCLUSION

Lower DHEAS serum levels in relationship to MetS become evident in women, but not in men, and have age differences as a confounding factor.

Prolactin, flupenthixol decanoate and first episode schizophrenia - clinical and laboratory correlates

First-episode psychosis (FEP) patients are more sensitive to neuroleptic side-effects such as hyperprolactinemia. We examined the prolactin levels of previously minimally treated patients with first episode schizophrenia over their first year of treatment with flupenthixol decanoate and the relationship between prolactin levels, gender and clinical features of schizophrenia. Prolactin levels were assessed at three monthly intervals in 126 patients with first-episode schizophrenia in a single-site study conducted over 12 months during treatment with flupenthixol decanoate according to a fixed protocol. The mean prolactin level for the total sample was 11.91 ng/ml (standard deviation [SD]15.52) at baseline. Women had higher levels of prolactin than men at month 3, 6 and 12, reaching statistical significance at month 12 (p = 0.02). At 12 months more women than men had hyperprolactinemia (defined as more than 20 ng/ml for males, and as more than 25 ng/ml for females (p = 0.007). Using a mixed effect model, there was a significant association between prolactin change scores over 12 months and gender (p = 0.025) as well as Positive and Negative Syndrome Scale (PANSS) total scores (p = 0.001). In addition female gender (p = 0.04) and age (p = 0.02) correlated with the risk of hyperprolactinemia as categorical variable. In this study treatment with flupenthixol decanoate was associated with relatively low levels of hyperprolactinemia, likely owing to flupenthixol's relatively atypical mode of action, as well as to the low doses used in our study. We found an inverse correlation between total PANSS scores and prolactin levels, which could support the suggested theory of prolactin having antipsychotic properties. Our study confirms the importance of gender on the prolactin raising effects of antipsychotic treatment.

Sex-specific effects of methylenetetrahydrofolate reductase polymorphisms on schizophrenia with methylation changes

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) is the critical enzyme in biotransformation. The polymorphism of MTHFR is a risk factor for schizophrenia. However, whether the MTHFR polymorphism is associated with schizophrenia disease phenotypes and what is the underlying mechanism of MTHFR polymorphism in schizophrenia is under-investigated. In this study, we aim to verify the correlation between MTHFR polymorphisms and clinical features of schizophrenia, while exploring the differential genomic methylation and disease related genes as the potential targets for schizophrenia.

METHOD

242 patients of schizophrenia and 234 matched healthy controls were enrolled in this study. Polymorphisms of MTHFR from three sites (C677T, A1298C, G1793A) were examined by Taqman fluorescence probe method in leukocytes from all subjects. The positive and negative syndrome scale (PANSS), trail making test (TMT) and Clinical Global Impression (CGI) were checked on patients. Genomic methylation was tested and analyzed in fields of differential methylation positions (DMPs) and enrichment of genes that are potentially related to schizophrenia.

RESULTS

Schizophrenic patients showed higher frequency of MTHFR polymorphisms at both single and multiple sites than healthy controls. Our data also showed that MTHFR C677T and multiple-site polymorphisms were positively correlated with PANSS positive rating, not negative score in male schizophrenia patients. Furthermore, while a significant reduction of global DNA methylation level was observed in schizophrenic patients, we also identified several genes which differentiated between schizophrenia and healthy controls at methylation levels.

CONCLUSIONS

This is a pilot study revealing that MTHFR polymorphisms at both single and multiple sites are related to the risk of schizophrenia and positive symptom of the disease. The risk of MTHFR polymorphism in schizophrenia and the clinical symptoms was only significant in male patients. While the sex-specific risk of MTHFR in schizophrenia is new and the reasons remain unanswered. Our methylation analysis suggested that there was significant hypomethylation of genomic DNA in schizophrenia patients with no sex difference. The correlation between MTHFR polymorphism and schizophrenia may attribute to the change of DNA methylation level, and some certain genes could be potential research objects for MTHFR effects on schizophrenia.

Sex Differences in Clinical and Functional Outcomes among Patients Treated in an Early Intervention Service for Psychotic Disorders: An Observational Study

OBJECTIVE

It has been shown that men with a longstanding psychotic disorder have worse clinical and functional outcomes than women. Our objectives were to examine whether these sex differences are also present among patients treated in an early intervention service (EIS) for psychosis and to determine if these differences are related to risk factors other than sex.

METHOD

Patients (N = 569) were assessed for demographic/clinical characteristics at entry and for symptoms/functioning over 2 years of treatment. Clinical outcomes included remission of positive, negative, and total symptoms. Functional outcomes included good functioning and functional remission. Logistic regression models examined the relationship between sex and outcomes after 1 and 2 years of treatment while controlling for the influence of other risk factors.

RESULTS

Men reported to be less educated and have a longer duration of untreated psychosis, poorer childhood and early adolescent premorbid functioning, higher rates of substance abuse/dependence disorders, greater severity of baseline negative symptoms, and poorer baseline social/occupational functioning than women. Women were more likely to achieve symptom remission than men after 2 years of treatment (negative odds ratio [OR], 1.69; 95% confidence interval [CI], 1.02 to 2.78; total OR, 1.79; 95% CI, 1.08 to 2.98). Women were also more likely than men to exhibit good functioning (OR, 1.61; 95% CI, 1.04 to 2.49) after 1 but not after 2 years of treatment. These results did not persist after controlling for other risk factors that could confound these associations (i.e., childhood premorbid functioning and age at onset of psychosis).

CONCLUSIONS

Sex differences seen in outcomes among patients treated in an EIS for psychosis may be largely influenced by the disparity of other risk factors that exist between the 2 sexes.

Alteration of miRNA-mRNA interactions in lymphocytes of individuals with schizophrenia

The aetiology of schizophrenia is complex, heterogeneous, and involves interplay of many genetic and environmental influences. While significant progress has been made in the understanding the common heritable component, we are still grappling with the genomic encoding of environmental risk. One class of molecule that has tremendous potential is miRNA. These molecules are regulated by genetic and environmental factors associated with schizophrenia and have a very significant impact on temporospatial patterns of gene expression. To better understand the relationship between miRNA and gene expression in the disorder we analysed these molecules in RNA isolated from peripheral blood mononuclear cells (PBMCs) obtained from an Australian cohort of 36 individuals with schizophrenia and 15 healthy controls using next-generation RNA sequencing. Significant changes in both mRNA and miRNA expression profiles were observed implicating important interaction networks involved in immune activity and development. We also observed sexual dimorphism, particularly in relation to variation in mRNA, with males showing significantly more differentially expressed genes. Interestingly, while we explored expression in lymphocytes, the systems biology of miRNA-mRNA interactions was suggestive of significant pleiotropy with enrichment of networks related to neuronal activity.

Estrogens and SERMS as adjunctive treatments for schizophrenia

More than thirty years have passed since sex and gender differences were noted in the age of onset, course and outcomes for schizophrenia. The 'estrogen hypothesis" was coined in the 1990's to describe neuroprotective effects of estrogen. Intervention studies in schizophrenia patients with estradiol and selective estrogen receptor modulators (SERMs) are promising but psychiatrists and other health practitioners do not generally take up this useful adjunctive treatment for their female patients with schizophrenia. The reasons for this are manifold, but overall a cultural shift in the practice of psychiatry is needed to recognise the specific needs of women with schizophrenia and tailor treatments, such as hormone adjuncts to improve the outcomes for this significant population. The two main aims of this article are to review the evidence and theory of estrogen treatments in schizophrenia and to recommend translation of adjunctive estrogen treatment into clinical practice for women with schizophrenia.

Does Gender Influence Outcome in Schizophrenia?

Good outcome of schizophrenia has several meanings and most of these meanings carry both positive and negative undertones depending on perspective. Currently, a person's subjective sense that illness has been partly overcome and that life is meaningful has come to be viewed as the most valid signpost of a good outcome. A review of the literature shows that women have certain advantages over men in that their illness starts at a later age and that their symptoms respond more quickly and more completely to available treatments. These advantages serve women well at the outset of illness but benefits appear to dissipate over time. Gender differences in outcome thus vary depending on the age of the patient. They also vary with the social and cultural background of the study population. Neither sex, therefore, has a monopoly on good outcome. The hope is that studying gender differences will uncover critical elements of good outcome that lead to interventions that will benefit both women and men.

Sex and gender differences in schizophrenic psychoses-a critical review

Many sex and gender differences in schizophrenic psychoses have been reported, but few have been soundly replicated. A stable finding is the later age of onset in women compared to men. Gender differences in symptomatology, comorbidity, and neurocognition seem to reflect findings in the general population. There is increasing evidence for estrogens being psychoprotective in women and for hypothalamic-pituitary-gonadal dysfunction in both sexes.More methodologically sound, longitudinal, multi-domain, interdisciplinary research investigating both sex (biological) and gender (psychosocial) factors is required to better understand the different pathogenesis and etiologies of schizophrenic psychoses in women and men, thereby leading to better tailored treatments and improved outcomes.

Methylenetetrahydrofolate reductase and psychiatric diseases

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme for the critical process of one-carbon metabolism involving folate and homocysteine metabolisms. It is known that some polymorphism of MTHFR would result in reduction of MTHFR enzyme activity as well as DNA methylation process, later shown to have significant impacts in various psychiatric diseases. However, it is unclear whether the polymorphism of MTHFR could be an independent or an add-on risk factor for specific psychiatric symptoms, such as anxiety, depression, positive, or negative symptoms of schizophrenia, or acts as risk factor for specific psychiatric disorders, such as schizophrenia, major depression, autisms, and bipolar disorders. It is also understudied on whether folate supplements could be an effective treatment for psychiatric patients with defect MTHFR activity. In this review, we not only gathered the most recent discoveries on MTHFR polymorphism and related DNA methylation in various psychiatric disorders, but also highlighted the potential relationships between MTHFR activity and implication of folate-related function in specific mental diseases.

Second-to-fourth digit length ratio is associated with negative and affective symptoms in schizophrenia patients

BACKGROUND

Higher levels of circulating oestrogens in women and testosterone in men have been shown to have a protective effect against the clinical manifestations of schizophrenia, mostly with respect to negative symptomatology. Certain studies suggest that they also have a protective effect against the neuropsychological impairment observed in the disease. We investigated whether greater prenatal exposure to estrogens in women and to testosterone in men, reflected by the 2D:4D ratio, was similarly associated with decreased negative symptomatology and improved neuropsychological functioning in patients.

METHOD

51 schizophrenia patients and 50 healthy participants were administered a neuropsychological battery. The 2D:4D ratio was measured in all participants. Positive, negative, and affective symptoms were assessed in patients. Regression analyses were conducted separately in male and female subgroups.

RESULTS

No associations with positive symptoms were revealed. In male patients, the 2D:4D ratio was positively associated with avolition and inversely associated with anxiety. In female patients, it was inversely associated with alogia, and tended to be positively associated with depression. No association between higher prenatal concentration of the relevant sex hormone and improved neuropsychological performance emerged in patients.

CONCLUSIONS

Higher concentrations of prenatal testosterone in male patients, and prenatal oestrogens in female patients, are associated with a decrement in certain aspects of negative symptomatology. In addition, prenatal sex hormone concentration seems to be associated with predisposition to anxiety in male patients, and to depression in female patients.

Genderwise clinical response of antipsychotics among schizophrenic patients: a prospective observational study from Lahore, Pakistan

OBJECTIVE

The study was aimed to evaluate the gender specific response to adherence and occurrence of side effects among schizophrenic patients in Lahore, Pakistan.

METHODS

A prospective study was performed for a period of 1 year among 180 newly diagnosed schizophrenics, aged 20-60 years to observe the symptoms, medication adherence and side effects. Morisky-Green-Levine Scale was used to evaluate medication adherence, LUNSER for side effects and PANSS to measure positive and negative symptoms. Data were analyzed using SPSS.

RESULTS

Positive symptoms (Male: Baseline 36.14 vs. endpoint 23.58, Female: 35.29 vs. 23.74) and negative symptoms (Males 27.9 vs. 20.05, Females 28.41 vs. 20.2) of schizophrenia were equally reduced after a follow up of 1 year in both the genders. Male population suffered more accumulative side effects (11.4 in males vs. 6.40 in females), extrapyramidal symptoms such as tardive dyskinesia and tremors (1.21 in males vs. 0.57 in females) and other side effects as compared to women (p ≤ .005). Males were found poorly adherent to antipsychotic treatment than females (93.3% in males vs. 6.7% in females (p ≤ .005).

CONCLUSIONS

Prescribing practices should not overlook sex specific factors like hormonal changes, altered brain morphology and socioeconomic factors that may be responsible for the difference in the response to the course of schizophrenia.

d-Serine administration affects nitric oxide synthase 1 adaptor protein and DISC1 expression in sex-specific manner

Antipsychotic medications are inefficient at treating symptoms of schizophrenia (SCZ), and N-methyl d-aspartate receptor (NMDAR) agonists are potential therapeutic alternatives. As such, these agonists may act on different pathways and proteins altered in the brains of patients with SCZ than do antipsychotic medications. Here, we investigate the effects of administration of the antipsychotic haloperidol and NMDAR agonist d-serine on function and expression of three proteins that play significant roles in SCZ: nitric oxide synthase 1 adaptor protein (NOS1AP), dopamine D2 (D2) receptor, and disrupted in schizophrenia 1 (DISC1). We administered haloperidol or d-serine to male and female Sprague Dawley rats via intraperitoneal injection for 12 days and subsequently examined cortical expression of NOS1AP, D2 receptor, and DISC1. We found sex-specific effects of haloperidol and d-serine treatment on the expression of these proteins. Haloperidol significantly reduced expression of D2 receptor in male, but not female, rats. Conversely, d-serine reduced expression of NOS1AP in male rats and did not affect D2 receptor expression. d-serine treatment also reduced expression of DISC1 in male rats and increased DISC1 expression in female rats. As NOS1AP is overexpressed in the cortex of patients with SCZ and negatively regulates NMDAR signaling, we subsequently examined whether treatment with antipsychotics or NMDAR agonists can reverse the detrimental effects of NOS1AP overexpression in vitro as previously reported by our group. NOS1AP overexpression promotes reduced dendrite branching in vitro, and as such, we treated cortical neurons overexpressing NOS1AP with different antipsychotics (haloperidol, clozapine, fluphenazine) or d-serine for 24 h and determined the effects of these drugs on NOS1AP expression and dendrite branching. While antipsychotics did not affect NOS1AP protein expression or dendrite branching in vitro, d-serine reduced NOS1AP expression and rescued NOS1AP-mediated reductions in dendrite branching. Taken together, our data suggest that d-serine influences the function and expression of NOS1AP, D2 receptor, and DISC1 in a sex-specific manner and reverses the effects of NOS1AP overexpression on dendrite morphology.

Pregnenolone as an adjunct to risperidone for treatment of women with schizophrenia: A randomized double-blind placebo-controlled clinical trial

There have been few studies of pregnenolone therapy in schizophrenia and those that exist have been subject to several critical limitations, thus yielding inconsistent results. We attempted to assess the therapeutic effect of pregnenolone in a patient sample as homogeneous as possible. In this randomized double-blind clinical trial, 82 female inpatients with chronic schizophrenia, who had discontinued their antipsychotic medications for at least one week in case of any oral antipsychotic medication or a month for any depot antipsychotic medication, received risperidone plus either pregnenolone (50 mg/day) or placebo for 8 weeks. Inclusion criteria were acute illness with a baseline Positive and Negative Syndrome Scale (PANSS) negative subscale score of ≥20. Exclusion criteria were the presence of severe depression or other concomitant psychiatric disorders. Primary outcome was defined as the difference in the PANSS total score change from baseline to week 8 in the pregnenolone group compared to the placebo group. No significant difference was found in the PANSS total score changes between the two arms (mean difference (CI 95%) = -9.41 (-20.24 to 1.41); p = 0.087). Significant differences were initially found for PANSS negative change scores (mean difference (CI 95%) = -2.61 (-5.03 to -0.19); p = 0.035) and general psychopathology change scores (mean difference (CI 95%) = -5.93 (-11.37 to -0.48); p = 0.033). However, these findings did not survive Bonferroni correction for multiple testing. While this trial may suggest a potential effect of pregnenolone on schizophrenia symptoms, further studies are warranted.

The placenta and neurodevelopment: sex differences in prenatal vulnerability

Prenatal insults, such as maternal stress, are associated with an increased neurodevelopmental disease risk and impact males significantly more than females, including increased rates of autism, mental retardation, stuttering, dyslexia, and attention deficit/hyperactivity disorder (ADHD). Sex differences in the placenta, which begin with sex chromosomes, are likely to produce sex-specific transplacental signals to the developing brain. Our studies and others have identified X-linked genes that are expressed at higher levels in the female placenta. Through a genome-wide screen after maternal stress in mice, we identified the X-linked gene O-linked N-acetylglucosamine transferase (OGT) and demonstrated its causality in neurodevelopmental programming producing a male-specific stress phenotype. Elucidating the sex-specific molecular mechanisms involved in transplacental signals that impact brain development is key to understanding the sex bias in neurodevelopmental disorders and is expected to yield novel insight into disease risk and resilience.

Selective enhancement of NMDA receptor-mediated locomotor hyperactivity by male sex hormones in mice

RATIONALE

Altered glutamate NMDA receptor function is implicated in schizophrenia, and gender differences have been demonstrated in this illness.

OBJECTIVES

This study aimed to investigate the interaction of gonadal hormones with NMDA receptor-mediated locomotor hyperactivity and PPI disruption in mice.

RESULTS

The effect of 0.25 mg/kg of MK-801 on locomotor activity was greater in male mice than in female mice. Gonadectomy (by surgical castration) significantly reduced MK-801-induced hyperlocomotion in male mice, but no effect of gonadectomy was seen in female mice or on amphetamine-induced locomotor hyperactivity. The effect of MK-801 on prepulse inhibition of startle (PPI) was similar in intact and castrated male mice and in ovariectomized (OVX) female mice. In contrast, there was no effect of MK-801 on PPI in intact female mice. Forebrain NMDA receptor density, as measured with [³H]MK-801 autoradiography, was significantly higher in male than in female mice but was not significantly altered by either castration or OVX.

CONCLUSIONS

These results suggest that male sex hormones enhance the effect of NMDA receptor blockade on psychosis-like behaviour. This interaction was not seen in female mice and was independent of NMDA receptor density in the forebrain. Male sex hormones may be involved in psychosis by an interaction with NMDA receptor hypofunction.

How gender affects the pharmacotherapeutic approach to treating psychosis - a systematic review

INTRODUCTION

The effectiveness, effective dosages and side effect profiles of antipsychotic medication differ significantly between the sexes. Areas covered: We present a systematic review of gender-differences in the treatment of psychosis focusing on randomized, controlled trials and meta-analyses. Expert opinion: Despite many years of research, the database on gender-differences affecting the pharmacotherapeutic approach to treating psychosis is insufficient. Currently, the US National Institute of Health encouraged the enrolment of female participants in federally supported phase III clinical trials to increase the data available of female patients. Emerging evidence points to a superior antipsychotic response in women, with men requiring higher dosages. In general, women metabolize drugs differently, resulting in side effects occuring more frequently when compared to men. In any case, women require electrocardiograms or bone density scans as well as diabetes and cardiovascular workups when treated with antipsychotics. Dose adjustments during the menstrual cycle (e.g. to raise antipsychotic doses premenstrually) should be considered. First-generation antipsychotics, drugs that are known to prolong QTc interval and increase prolactin levels should be avoided in postmenopausal female patients. Furthermore, the effects of antipsychotics during pregnancy and breastfeeding have been investigated insufficiently, and more research is urgently needed.

Oestrogens, prolactin, hypothalamic-pituitary-gonadal axis, and schizophrenic psychoses

Interest is growing in the potential effect of gonadal hormones, prolactin, and the hypothalamic-pituitary-gonadal axis in schizophrenic psychoses. Many studies from clinical, epidemiological, and fundamental research have confirmed that oestradiol, the main component of oestrogens, can have protective effects in schizophrenic psychoses. Furthermore, many patients with schizophrenic psychoses-even in the untreated prodromal stages-have hyperprolactinaemia and gonadal dysfunction, with oestrogen deficiency in women and testosterone deficiency in men. The understanding of the pathogenetic mechanisms underlying these findings could contribute to a better understanding of the aetiopathogenesis of schizophrenic psychoses and improve therapeutic approaches. In this Series paper, we aim to review methodologically sound studies in this area, propose a theory to explain these findings in the context of psychosis, and suggest therapeutic strategies and implications for further research.

Progesterone Alters Kynurenine Pathway Activation in IFN-γ-Activated Macrophages - Relevance for Neuroinflammatory Diseases

We have previously demonstrated that the kynurenine pathway (KP), the major biochemical pathway for tryptophan metabolism, is dysregulated in many inflammatory disorders that are often associated with sexual dimorphisms. We aimed to identify a potential functional interaction between the KP and gonadal hormones. We have treated primary human macrophages with progesterone in the presence and absence of inflammatory cytokine interferon-gamma (interferon-γ) that is known to be a potent inducer of regulating the KP enzyme. We found that progesterone attenuates interferon-γ-induced KP activity, decreases the levels of the excitotoxin quinolinic acid, and increases the neuroprotective kynurenic acid levels. We also showed that progesterone was able to reduce the inflammatory marker neopterin. These results may shed light on the gender disparity in response to inflammation.

The relationship between sex hormone profiles and symptoms of schizophrenia in men

AIM

Recent studies have shown that sex hormones play a role in the development of schizophrenia and the severity of disease symptoms. However, study results have been inconsistent. This study compares the relationship between severity of disease symptoms and levels of estradiol, progesterone, testosterone, DHEA-S, prolactin and cortisol in male schizophrenia patients and a matched group of healthy controls.

METHODS

The study sample included 38 men diagnosed with schizophrenia according to DSM-IV TR criteria, and matched by age with 38 healthy controls. All subjects were between 18 and 55years old, 22 of them had been treated with olanzapine and 16 with quetiapine. Their symptom severity was evaluated by administering the Scale for the Assessment of Positive Symptoms (SAPS) and Scale for the Assessment of Negative Symptoms (SANS). Hormone levels for schizophrenia patients and healthy controls were evaluated using a chemiluminescence immunoassay method. The hormone profiles of schizophrenia patients and healthy controls were compared statistically. We examined the relationship between subjects' and controls' hormone levels and their scores on the SANS and SAPS scales.

RESULTS

This study found statistically significant elevated levels of serum DHEA-S, cortisol, and prolactin (p=0.012, p=0.009, and p=0.021 respectively), in schizophrenia patients as compared to a control group. Subjects' serum estradiol and progesterone levels (p=0.005 and p<0.001 respectively), were significantly lower than controls' levels. There was a positive correlation between subjects' SANS scores, estradiol (p=0.001) and progesterone levels (p=0.027). No relationship was found between subjects' hormone levels and their SAPS scores.

CONCLUSION

There may be a relationship between progesterone, estradiol, cortisol and DHEA-S, and the pathophysiology of schizophrenia. These hormones can be used as biological markers for the disorder of schizophrenia. More studies with larger sample sizes are needed to confirm these findings.

Study of the tetraspanin 18 association with schizophrenia in a Han Chinese population

A genome-wide association study of Han Chinese samples identified three single-nucleotide polymorphisms in the tetraspanin 18 (TSPAN18) gene to be associated with schizophrenia. However, the replication of the TSPAN18 association was inconsistent across studies. To explore the possible reason for poor replication, we conducted a case-control study to validate the TSPAN18 finding in an independent Chinese sample. The frequency of rs11038167 minor allele (A) was significantly higher only in female patients with thought disorder. Our result suggested that the TSPAN18 gene may be involved in the development of psychotic symptoms and contribute to clinical heterogeneity of schizophrenia.

Go and NoGo: modulation of electrophysiological correlates by female sex steroid hormones

RATIONALE

The behavioral and electrophysiological responses in a Go/NoGo task are objective measures of executive functioning that may be impaired in clinical conditions. Prior to the wider application of Go/NoGo tasks in clinics, it is tempting to evaluate factors causing modulation of the responses.

OBJECTIVE

We aimed to evaluate the effect of different levels of female sex steroids on Go/NoGo task-related ERPs in healthy females.

METHODS

Thirty-four young healthy females performed an equiprobable (50/50) auditory Go/NoGo task. Amplitudes and latencies of N2 and P3 peaks from Fz, Cz, and Pz electrodes were evaluated. 17β-estradiol and progesterone levels in saliva samples were measured. Electrophysiological measures were correlated to 17β-estradiol and progesterone concentrations.

RESULTS

The diverse pattern of modulation of P3 latencies was shown: higher levels of 17β-estradiol contributed to Go-P3 latency prolongation, and higher levels of progesterone contributed to NoGo-P3 latency shortening. Higher levels of 17β-estradiol were associated with more negative frontal N2 amplitude in both conditions.

CONCLUSIONS

The relationship between electrophysiological correlates of executive functioning to individual hormonal levels points to a broader range of variation sources in healthy subjects which might mask or pronounce between-group differences in clinical studies.

Altering the course of schizophrenia: progress and perspectives

Despite a lack of recent progress in the treatment of schizophrenia, our understanding of its genetic and environmental causes has considerably improved, and their relationship to aberrant patterns of neurodevelopment has become clearer. This raises the possibility that 'disease-modifying' strategies could alter the course to - and of - this debilitating disorder, rather than simply alleviating symptoms. A promising window for course-altering intervention is around the time of the first episode of psychosis, especially in young people at risk of transition to schizophrenia. Indeed, studies performed in both individuals at risk of developing schizophrenia and rodent models for schizophrenia suggest that pre-diagnostic pharmacotherapy and psychosocial or cognitive-behavioural interventions can delay or moderate the emergence of psychosis. Of particular interest are 'hybrid' strategies that both relieve presenting symptoms and reduce the risk of transition to schizophrenia or another psychiatric disorder. This Review aims to provide a broad-based consideration of the challenges and opportunities inherent in efforts to alter the course of schizophrenia.

Sex dependency of inhibitory control functions

BACKGROUND

Inhibition of irrelevant responses is an important aspect of cognitive control of a goal-directed behavior. Females and males show different levels of susceptibility to neuropsychological disorders such as impulsive behavior and addiction, which might be related to differences in inhibitory brain functions.

METHODS

We examined the effects of 'practice to inhibit', as a model of rehabilitation approach, and 'music', as a salient contextual factor in influencing cognition, on the ability of females and males to perform a stop-signal task that required inhibition of initiated or planned responses. In go trials, the participants had to rapidly respond to a directional go cue within a limited time window. In stop trials, which were presented less frequently, a stop signal appeared immediately after the go-direction cue and the participants had to stop their responses.

RESULTS

We found a significant difference between females and males in benefiting from practice in the stop-signal task: the percentage of correct responses in the go trials increased, and the ability to inhibit responses significantly improved, after practice in females. While listening to music, females became faster but males became slower in responding to the go trials. Both females and males became slower in performing the go trials following an error in the stop trials; however, music significantly affected this post-error slowing depending on the sex. Listening to music decreased post-error slowing in females but had an opposite effect in males.

CONCLUSIONC

Here, we show a significant difference in executive control functions and their modulation by contextual factors between females and males that might have implications for the differences in their propensity for particular neuropsychological disorders and related rehabilitation approaches.

Improvement of Psychotic Symptoms and the Role of Tissue Plasminogen Activator

Tissue plasminogen activator (tPA) mediates a number of processes that are pivotal for synaptogenesis and remodeling of synapses, including proteolysis of the brain extracellular matrix, degradation of adhesion molecules, activation of neurotrophins, and activation of the N-methyl-d-aspartate receptor. Abnormalities in these processes have been consistently described in psychotic disorders. In this paper, we review the physiological roles of tPA, focusing on conditions characterized by low tPA activity, which are prevalent in schizophrenia. We then describe how tPA activity is influenced by lifestyle interventions and nutritional supplements that may ameliorate psychotic symptoms. Next, we analyze the role of tPA in the mechanism of action of hormones and medications effective in mitigating psychotic symptoms, such as pregnenolone, estrogen, oxytocin, dopamine D3 receptor antagonists, retinoic acid, valproic acid, cannabidiol, sodium nitroprusside, N-acetyl cysteine, and warfarin. We also review evidence that tPA participates in the mechanism by which electroconvulsive therapy and cigarette smoking may reduce psychotic symptoms.