Sex differences in early childhood

Differences in several aspects of the developing personality in boys and girls are described. These differences affect mainly modes of impulse control and drive expression: boys tend to discharge aggression through muscular discharge; girls are more contained and show a greater propensity for involvement of affective changes. A particular carry-over of modes characteristic of the oral phase throughout development is suggested in girls. These and other sex differences are discussed in relation to their multiple determinants occurring at different stages of development. The contribution of early appearing sex differences to the selection of various sex-linked personality factors (symptoms, identifications, conflicts, and the like) is discussed.A preliminary version of this paper was presented at the meeting of the American Association of Psychiatric Clinics for Children, New York City, in November 1968. The author is indebted to Dr. P. B. Neubauer for his valuable suggestions.     

Sex differences in the effect of amphetamine on immediate early gene expression in the rat dorsal striatum

Amphetamine (AMPH)-induced dopamine release in the striatum and AMPH-induced behavior in the rat have been demonstrated to be influenced by sex and hormonal status. The experiments reported here were conducted, therefore, to examine sex differences, hormonal influences and estrous cycle-dependent changes in AMPH-induced immediate early gene expression in the dorsal striatum. Cell counts were taken at three rostrocaudal levels from three to four regions of the dorsal striatum at each level (ventromedial, dorsomedial, dorsolateral, ventrolateral). The immunohistochemical localization of calbindin was used as a control. We report here that females on the afternoon of proestrus had a significantly greater percent of Fos-positive neurons after AMPH across the dorsolateral region of the middle and caudal striatum and in the ventrolateral region of the caudal striatum compared to females in diestrus, ovariectomized (OVX) females, castrated (CAST) males and intact males. There was no difference in AMPH-induced immediate early gene expression between OVX and diestrous rats. There were also no significant differences between CAST and intact males in AMPH-induced Fos expression, with the exception of the ventrolateral caudal striatum. In sum, the present findings indicate that AMPH-induced Fos expression is sexually dimorphic and modulated by gonadal hormones in lateral regions of the rat dorsal striatum.     

Gender differences in the effect of early life trauma on hypothalamic-pituitary-adrenal axis functioning

Background: The objective of this study was to examine the modifying effect of gender on the association between early life trauma and the hypothalamic–pituitary–adrenal (HPA) axis response to a pharmacologic challenge and a social stress task in men and women. Participants (16 men, 23 women) were the control sample of a larger study examining HPA axis function. Individuals with major depressive disorder, posttraumatic stress disorder, bipolar disorder, or psychotic or eating disorders were excluded. Methods: In two test sessions, subjects received 1 µg/kg of corticotropin‐releasing hormone (CRH) intravenously and participated in the Trier Social Stress Test (TSST). Primary outcomes included plasma cortisol and corticotropin levels measured at baseline and more than five time points following the challenges. Predictors included gender and early life trauma, as measured by the Early Trauma Index. Using factor analysis, the domains general trauma, severe trauma, and the effects of trauma were established. Using regression, these constructs were used to predict differential HPA reactivity in men and women following the challenges. Results: The three factors accounted for the majority of the variance in the ETI. Following the CRH challenge, women had higher overall corticotropin response as dictated by the area under the curve analysis. There were no significant associations between trauma and neuroendocrine response to the TSST. Conclusions: CRH challenge results indicate that gender differences in the impact of early trauma may help explain the differential gender susceptibility to psychopathology following adverse childhood events. This may help explain gender differences in some stress‐sensitive psychiatric disorders. Depression and Anxiety, 2011. © 2011 Wiley‐Liss, Inc.     

Epigenetics and gene expression profile in first-episode psychosis: The role of childhood trauma

Childhood Trauma (CT) mediation of the epigenome and its impact on gene expression profile could provide a mechanism for the gene-environment interaction underling psychosis. We reviewed the evidence concerning epigenetic and gene expression modifications associated with CT in both First-Episode Psychosis (FEP) and healthy subjects. In order to explore the relative role of psychosis itself in determining these modifications, evidence about FEP and epigenetics/gene expression was also summarized. We performed a systematic search on PubMed, last updated in December 2016. Out of 2966 potentially relevant records, only 41 studies were included. CT resulted associated: in FEP subjects, with global DNA hypo-methylation and reduced BDNF gene-expression; in healthy subjects, with hyper-methylation of SLC6A4, NR3C1, KITLG, and OXTR; hypo-methylation of FKBP5, IL-6, and BDNF; increased IL1B, IL8, and PTGS gene expression; and decreased SLC6A4 gene expression. FEP showed global DNA hypo-methylation; increased methylation and reduced gene expression of GCH1; hyper-expression of MPB, NDEL1, AKT1, and DICER1; and hypo-expression of DROSHA, COMT, and DISC1 in comparison with healthy controls.     

Sex differences in childhood anger and aggression

There are few differences in the frequency or intensity of men's and women's self-reported or observed anger. Women are more likely to be angered by relationship conflicts than men. Men are more frequently the targets of anger than women. Typically, men see the expression of anger as exerting dominance, where as women view it as a loss of control. There are also sex differences in the mode of anger expression. At ages 8 and older, girls are more likely to engage in "relational" aggression (eg, deliberate social ostracism). The most consistent and salient difference in anger expression is women's tendency to cry when angry, whereas men are more likely to throw things or hit. The difference in physical aggression appears in children who are as young as 1 to 2 years of age. Despite an overall reduction in physical aggression after 2 to 3 years of age, the sex difference remains consistent into adulthood. In contrast to differences in physical aggression, differences in anger are few and inconsistent up to 4 or 5 years of age. By this age, girls tend to suppress the expression of anger consciously. By about 7 to 8 years of age, adult like differences become more consistent, with boys expressing more anger.     

Sex differences in the cortisol response to awakening in recent onset psychosis

A dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis has been suggested as a factor in the etiology and exacerbation of psychosis, but has not been reported consistently. Sex differences are apparent in many aspects of psychotic disorders and may explain some of the equivocation associated with the regulation of the HPA axis in the illness. The present study compared the cortisol response to awakening (CRA) in 27 patients (16 men and 11 women) with recent onset of psychosis (within the past 2 years) and 40 age and gender matched controls. Within the patient group, we also assessed the relationship between the CRA and positive and negative symptoms of psychosis, anxiety and depression. The CRA in patients was not significantly different from controls. However, within the patient group, we observed a significant sex difference, with a blunted cortisol response to awakening in men but not in women (F=7.26; p<0.002). This difference could not be explained by differences between male and female patients in awakening time, medication, or diagnosis of schizophrenia vs. affective psychosis. Cortisol levels were not related to symptom measures. Our findings demonstrate a dysregulation of the HPA axis in male patients with recent onset of psychosis. This sex specificity might be related to and explain in part the unfavorable course of the illness observed in men.     

Sex differences in the activation of language cortex during childhood

Sex differences have been well documented in the behavioral literature but have occurred inconsistently in the neuroimaging literature. This investigation examined the impact of subject age, language task, and cortical region on the occurrence of sex differences in functional magnetic resonance imaging. Two hundred and five (104 m, 101 f) right handed, monolingual English speaking children between the ages of 5 and 18 years were enrolled in this study. The study used fMRI at 3T to evaluate BOLD signal variation associated with sex, age, and their interaction. Children completed up to four language tasks, which involved listening to stories, prosody processing, single word vocabulary identification, and verb generation. A sex difference for behavioral performance was found for the prosodic processing task only. Brain activation in the classical left hemisphere language areas of the brain and their right homologues were assessed for sex differences. Although left lateralization was present for both frontal and temporal regions for all but the prosody task, no significant sex differences were found for the degree of lateralization. Sex x age interaction effects were found for all but the task involving single word vocabulary. However effect sizes associated with the sex differences were small, which suggests that relatively large sample sizes would be needed to detect these effects reliably.     

童年创伤对精神分裂症影响的研究进展

精神分裂症一种是重大的致残性疾病,其发病通常与环境因素有一定关联,童年创伤作 为常见的环境因素,其对精神分裂症的影响仍未完全阐明,现主要通过复习童年创伤对精神分裂症的 有关研究进展,包括病因学、脑部结构及功能、症状学等方面,从不同方向解读童年创伤对精神分裂症 的影响。     

Sex differences in emotional reactivity to daily life stress in psychosis

BACKGROUND: The expression of schizophrenia has been reported to differ between the sexes. The current study investigates whether these sex differences in clinical expression are reflected in one underlying mechanism that may be causally related to psychosis, namely increases in stress sensitivity in daily life. METHOD: Forty-two participants (22 men, 20 women) with Research Diagnostic Criteria-defined psychotic disorder in a state of clinical remission were studied with the Experience Sampling Method (a structured diary technique assessing current context and mood in daily life) to assess (1) appraised subjective stress related to daily events and activities and (2) emotional reactivity conceptualized as changes in both negative affect and positive affect in relation to the subjective stress. Data were collected from January 1997 to May 1999. RESULTS: Multilevel regression analyses revealed that women reported a significantly (p < .05) increased emotional reactivity to daily life stress compared with men, reflected in both an increase in negative affect and a decrease in positive affect. CONCLUSION: These results suggest that gender differences may not be limited to the characteristics of psychosis but may also be reflected in underlying etiologic mechanisms. Furthermore, these results might strengthen the hypothesis that women are more susceptible than men to a schizoaffective expression of schizophrenia.     

Sex differences in the phenotypic expression of avian dystrophy

Although the gene for muscular dystrophy in chickens is not sex-linked, results from clinical tests suggest that it is expressed differently in males and females. As measurement of muscle contractile responses provides a quantitative index for the severity of the disease, the contractile properties of the extensor digitorum communis muscle were examined in normal and dystrophic chickens with respect to sex. Furthermore, these differences were examined in young (6 to 9 weeks) and old (greater than 6 months) chickens. Results showed that age-related sex differences were apparent for those mechanical parameters of the muscle (in particular the posttetanic potentiation and posttetanic contracture) known to distinguish normal and dystrophic birds. The sex differences observed in the younger group indicate that the female birds were more severely affected by the disease than were the male. In the older group, the male were affected by the disease more severely than age-matched female birds. If the inheritance pattern is truly autosomal then it is likely that one or more developmental factors interact with the dystrophic genotype and alter the dystrophic phenotype.     

Sex differences in symptoms of psychosis in a non-selected,general population sample

BACKGROUND: Little is known about sex differences in psychosis beyond the borders of clinical disorder. METHODS: A general population sample of 7,076 subjects was assessed using the Composite International Diagnostic Interview, in order to explore sex differences in the prevalence of any positive and negative symptoms of psychosis, and to examine to what degree any differences could be explained by differences in level of affective symptoms. RESULTS: Male sex was associated with higher prevalence of negative symptoms (OR = 1.6, 95% CI = 1.0, 2.5), independent of differences in affective symptoms and presence of DSM-III-R psychotic disorder. Women had higher rates of positive psychotic experiences (OR = 0.8, 95% CI = 0.7, 0.9), but this difference disappeared after adjustment for depressive symptoms (adjusted OR = 1.2, 95% CI = 0.9, 1.5). CONCLUSION: The sex differences in psychopathology that are seen in schizophrenia are expressed beyond the clinical phenotype, suggesting sex-dependent continuous and normal variation of several psychosis dimensions. The higher rates of positive psychotic experiences seen in women may be secondary to differences in the rate of affective symptoms.     

Sex differences in asymmetry in the facial expression of emotion

Two measures of facial asymmetry (preferred eye winking and eyebrow raising facility) were taken for 255 subjects. As predicted, males displayed significantly greater left-side facial asymmetry than did females, although the sex differences were not great. The findings lend support to prior research suggesting hemispheric asymmetry in the control of emotional expression.     

Sex differences in the clinical manifestations of Alzheimer disease pathology

CONTEXT: Sex differences in risk of clinically diagnosed Alzheimer disease (AD) have been studied extensively, but little is known about the relation of the pathologic indices of AD to the clinical manifestations of the disease in men compared with women. OBJECTIVE: To test whether the relation of AD pathology to the clinical manifestations of the disease differs in men and women. DESIGN: Longitudinal, clinicopathologic cohort study. PARTICIPANTS AND SETTING: Analyses were conducted on 141 older Catholic clergy members who underwent detailed annual clinical evaluations and brain autopsy at death. The number of neuritic plaques, diffuse plaques, and neurofibrillary tangles in a 1-mm2 area sampled from 4 cortical regions was counted, and a global measure of AD pathology (range, 0-2.98 U) and specific measures of each pathology were derived. MAIN OUTCOME MEASURES: Clinical diagnosis of probable AD and level of global cognitive function at the last evaluation before death. RESULTS: Women had more global AD pathology than did men (P = .04), due primarily to more neurofibrillary tangles (P = .02). At the last evaluation before death, 57 persons met clinical criteria for probable AD (34 [60%] of them women). In logistic regression models, sex was not related to odds of clinical AD (odds ratio [OR], 1.35; 95% confidence interval [CI], 0.56-3.25), but the relation of global AD pathology to clinical diagnosis differed for men and women. Each additional unit of AD pathology was associated with a nearly 3-fold increase in the odds of clinical AD in men (OR, 2.82; 95% CI, 1.03-7.65) compared with a more than 20-fold increase in the odds of clinical AD in women (OR, 22.67; 95% CI, 5.11-100.53). Results were unchanged after controlling for potential confounders or using level of cognition as the outcome. CONCLUSION: These data suggest that AD pathology is more likely to be clinically expressed as dementia in women than in men.     

Sex differences in aromatase gene expression in the medaka brain

The brain of teleost fish exhibits a significant degree of sexual plasticity, even in adulthood. This unique feature is almost certainly attributable to a teleost-specific sexual differentiation process of the brain, which remains largely unknown. To dissect the molecular basis of sexual differentiation of the teleost brain, we searched for genes differentially expressed between both sexes in the medaka brain. One gene identified in the screen, cyp19a1b, which encodes the steroidogenic enzyme aromatase, was selected for further analysis. As opposed to the situation in most vertebrates, medaka cyp19a1b is expressed at higher levels in the adult female brain than the male brain. The female-biased expression in the brain is consistent regardless of reproductive or diurnal cycle. Medaka cyp19a1b is expressed throughout the ventricular zones in wide areas of the brain, where, in most regions, females have a greater degree of expression compared to males, with the optic tectum exhibiting the most conspicuous predominance in females. Contrary to what is known in mammals, cyp19a1b expression exhibits neither a transient elevation nor a sex difference in medaka embryos. It is not until just before the onset of puberty that cyp19a1b expression in the medaka brain is sexually differentiated. Finally, cyp19a1b expression in the medaka brain is not under the direct control of sex chromosome genes but relies mostly, if not solely, on oestrogen derived from the gonad. These unique properties of aromatase expression in the brain probably contribute substantially to the less rigid sexual differentiation process, thus ensuring remarkable sexual plasticity in the teleost brain.     

Sex differences in anxiety and depression clinical perspectives

Sex differences are prominent in mood and anxiety disorders and may provide a window into mechanisms of onset and maintenance of affective disturbances in both men and women. With the plethora of sex differences in brain structure, function, and stress responsivity, as well as differences in exposure to reproductive hormones, social expectations and experiences, the challenge is to understand which sex differences are relevant to affective illness. This review will focus on clinical aspects of sex differences in affective disorders including the emergence of sex differences across developmental stages and the impact of reproductive events. Biological, cultural, and experiential factors that may underlie sex differences in the phenomenology of mood and anxiety disorders are discussed.