Cortical brain structure and sexual orientation in adult females with bipolar disorder or attention deficit hyperactivity disorder.
ABSTRACT: Nonheterosexual individuals have higher risk of psychiatric morbidity. Together with growing evidence for sexual orientation-related brain differences, this raises the concern that sexual orientation may be an important factor to control for in neuroimaging studies of neuropsychiatric disorders.We studied sexual orientation in adult psychiatric patients with bipolar disorder (BD) or ADHD in a large clinical cohort (N = 154). We compared cortical brain structure in exclusively heterosexual women (HEW, n = 29) with that of nonexclusively heterosexual women (nHEW, n = 37) using surface-based reconstruction techniques provided by FreeSurfer.The prevalence of nonheterosexual sexual orientation was tentatively higher than reported in general population samples. Consistent with previously reported cross-sex shifted brain patterns among homosexual individuals, nHEW patients showed significantly larger cortical volumes than HEW in medial occipital brain regions.We found evidence for a sex-reversed difference in cortical volume among nonheterosexual female patients, which provides insights into the neurobiology of sexual orientation, and may provide the first clues toward a better neurobiological understanding of the association between sexual orientation and mental health. We also suggest that sexual orientation is an important factor to consider in future neuroimaging studies of populations with certain mental health disorders.
Project description:Previous neuroimaging studies demonstrated sex and also sexual orientation related structural and functional differences in the human brain. Genetic information and effects of sex hormones are assumed to contribute to the male/female differentiation of the brain, and similar effects could play a role in processes influencing human's sexual orientation. However, questions about the origin and development of a person's sexual orientation remain unanswered, and research on sexual orientation related neurobiological characteristics is still very limited. To contribute to a better understanding of the neurobiology of sexual orientation, we used magnetic resonance imaging (MRI) in order to compare regional cortical thickness (Cth) and subcortical volumes of homosexual men (hoM), heterosexual men (heM) and heterosexual women (heW). hoM (and heW) had thinner cortices primarily in visual areas and smaller thalamus volumes than heM, in which hoM and heW did not differ. Our results support previous studies, which suggest cerebral differences between hoM and heM in regions, where sex differences have been reported, which are frequently proposed to underlie biological mechanisms. Thus, our results contribute to a better understanding of the neurobiology of sexual orientation.
Project description:Cerebral responses to putative pheromones and objects of sexual attraction were recently found to differ between homo- and heterosexual subjects. Although this observation may merely mirror perceptional differences, it raises the intriguing question as to whether certain sexually dimorphic features in the brain may differ between individuals of the same sex but different sexual orientation. We addressed this issue by studying hemispheric asymmetry and functional connectivity, two parameters that in previous publications have shown specific sex differences. Ninety subjects [25 heterosexual men (HeM) and women (HeW), and 20 homosexual men (HoM) and women (HoW)] were investigated with magnetic resonance volumetry of cerebral and cerebellar hemispheres. Fifty of them also participated in PET measurements of cerebral blood flow, used for analyses of functional connections from the right and left amygdalae. HeM and HoW showed a rightward cerebral asymmetry, whereas volumes of the cerebral hemispheres were symmetrical in HoM and HeW. No cerebellar asymmetries were found. Homosexual subjects also showed sex-atypical amygdala connections. In HoM, as in HeW, the connections were more widespread from the left amygdala; in HoW and HeM, on the other hand, from the right amygdala. Furthermore, in HoM and HeW the connections were primarily displayed with the contralateral amygdala and the anterior cingulate, in HeM and HoW with the caudate, putamen, and the prefrontal cortex. The present study shows sex-atypical cerebral asymmetry and functional connections in homosexual subjects. The results cannot be primarily ascribed to learned effects, and they suggest a linkage to neurobiological entities.
Project description:The neurobiology of sexual preference is often discussed in terms of cerebral sex dimorphism. Yet, our knowledge about possible cerebral differences between homosexual men (HoM), heterosexual men (HeM) and heterosexual women (HeW) are extremely limited. In the present MRI study, we addressed this issue investigating measures of cerebral anatomy and function, which were previously reported to show sex difference. Specifically, we asked whether there were any signs of sex atypical cerebral dimorphism among HoM, if these were widely distributed (providing substrate for more general 'female' behavioral characteristics among HoM), or restricted to networks involved in self-referential sexual arousal. Cortical thickness (Cth), surface area (SA), subcortical structural volumes, and resting state functional connectivity were compared between 30 (HoM), 35 (HeM) and 38 (HeW). HoM displayed a significantly thicker anterior cingulate cortex (ACC), precuneus, and the left occipito-temporal cortex compared to both control groups. These differences seemed coordinated, since HoM also displayed stronger cortico-cortical covariations between these regions. Furthermore, functional connections within the default mode network, which mediates self- referential processing, and includes the ACC and precuneus were significantly weaker in HoM than HeM and HeW, whereas their functional connectivity between the thalamus and hypothalamus (important nodes for sexual behavior) was stronger. In addition to these singular features, HoM displayed 'female' characteristics, with a similar Cth in the left superior parietal and cuneus cortices as HeW, but different from HeM. These data suggest both singular and sex atypical features and motivate further investigations of cerebral midline structures in relation to male homosexuality.
Project description:Research is lacking on psychological distress and disorder among sexual minority medical students (students who identify as nonheterosexual). If left unaddressed, distress may result in academic and professional difficulties and undermine workforce diversity goals. The authors compared depression, anxiety, and self-rated health among sexual minority and heterosexual medical students.This study included 4,673 first-year students who self-reported sexual orientation in the fall 2010 baseline survey of the Medical Student Cognitive Habits and Growth Evaluation Study, a national longitudinal cohort study. The authors used items from published scales to measure depression, anxiety, self-rated health, and social stressors. They conducted bivariate and multivariate analyses to estimate the association between sexual identity and depression, anxiety, and self-rated health.Of 4,673 students, 232 (5.0%) identified as a sexual minority. Compared with heterosexual students, after adjusting for relevant covariates, sexual minority students had greater risk of depressive symptoms (adjusted relative risk [ARR] = 1.59 [95% confidence interval, 1.24-2.04]), anxiety symptoms (ARR = 1.64 [1.08-2.49]), and low self-rated health (ARR = 1.77 [1.15-2.60]). Sexual minority students were more likely to report social stressors, including harassment (22.7% versus 12.7%, P < .001) and isolation (53.7% versus 42.8%, P = .001). Exposure to social stressors attenuated but did not eliminate the observed associations between minority sexual identity and mental and self-reported health measures.First-year sexual minority students experience significantly greater risk of depression, anxiety, and low self-rated health than heterosexual students. Targeted interventions are needed to improve mental health and well-being.
Project description:BACKGROUND:Sexual minority (gay, lesbian, and bisexual) individuals experience elevated mood disorders and suicidality compared to their heterosexual counterparts. However, to date, these sexual orientation disparities have yet to be examined among middle childhood-aged participants. METHODS:Data were employed from the baseline wave of the Adolescent Brain Cognitive Development (ABCD) study, a U.S. representative sample. Population-level weighting was utilized, resulting in an analytic sample of N?=?8,204,013 (nunweighted?=?4519) children between the ages of 9 and 10 years: with 70,952 (nunweighted?=?43) identifying as sexual minories (0.9% of the population). Structured clinical interviews were used to assess mood disorders (i.e., depressive and bipolar disorders) and suicidality. Sexual orientation (sexual minority vs. heterosexual) was examined as the focal independent variable. RESULTS:The overall prevalence of mood disorders was 7.1%. Sexual minority children (22.5%) possessed a higher rate than heterosexual children (6.9%). The overall prevalence of suicidality was 4.8%; sexual minority children (19.1%) possessed a higher rate than heterosexual children (4.6%). LIMITATIONS:Sexual orientation assessment did not include attraction, and thus, results may represent a lower bound estimate of sexual minorities. CONCLUSIONS:Sexual orientation disparities in mood disorders and suicidality appear to develop as early as middle childhood. Clinicians are encouraged to assess sexual orientation among children as young as 9-10 years old, and provide appropriate normalization of sexual orientation, and referrals for mental health treatment, as indicated.
Project description:Background Sexual orientation has been suggested to affect executive function, of which the neurobiological basis is still largely unknown. In this study, we explored the interrelationship between neuropsychological characteristics in homosexual and heterosexual men and their anatomical connectome by graph theoretical analysis. Methods Fifty-three homosexual and 47 heterosexual males underwent diffusion tensor magnetic resonance imaging (MRI) and neuropsychological assessments. Whole-brain anatomical networks were constructed using white matter tractography, performed on the diffusion tensor imaging data. Neuropsychological tests included the Wisconsin Card Sorting Test (WCST), the Continuous Performance Test (CPT) and the Trail-Making Test (TMT). Results The cognitive performance of homosexual men was significantly poorer than their heterosexual counterparts in terms of WCST total correct responses. Anatomical connectome analysis revealed a lower (P=0.001) anatomical connectivity between left PoCG and left SMG (P=0.003) in homosexual men as compared to heterosexual men. Linear regression analyses showed that the WCST total correct responses score was significantly linked with sexual orientation (P=0.001). The anatomical connectivity strength between left PoCG and left SMG was also shown to be significantly correlated with sexual orientation (P=0.039) and education (P=0.047). Conclusions Our study demonstrated the differences in the performance of WCST and anatomical connectome of large-scale brain networks between homosexual and heterosexual men, extending our understanding of the brain’s circuitry and the characteristics of executive function in men of different sexual orientation.
Project description:Fifty five Armed Forces personnel detected to be seropositives for human immunodeficiency virus were the subjects of the study. After baseline clinical evaluation, laboratory investigations and Centre for Disease Control classification, through a semistructured interview, their sexual orientation, behaviour and psychiatric morbidity were assessed. Sixtynine percent had another sexually transmitted disease as comorbidity. Heterosexual contact was responsible for the infection in 54 out of 55 subjects. Seven patients were freshly diagnosed to have psychiatric illness.
Project description:The neurobiology of sexual orientation is frequently discussed in terms of cerebral sex dimorphism (defining both functional and structural sex differences). Yet, the information about possible cerebral differences between sex-matched homo and heterosexual persons is limited, particularly among women. In this multimodal MRI study, we addressed these issues by investigating possible cerebral differences between homo and heterosexual persons, and by asking whether there is any sex difference in this aspect. Measurements of cortical thickness (Cth), subcortical volumes, and functional and structural resting-state connections among 40 heterosexual males (HeM) and 40 heterosexual females (HeF) were compared with those of 30 homosexual males (HoM) and 30 homosexual females (HoF). Congruent with previous reports, sex differences were detected in heterosexual controls with regard to fractional anisotropy (FA), Cth, and several subcortical volumes. Homosexual groups did not display any sex differences in FA values. Furthermore, their functional connectivity was significantly less pronounced in the mesial prefrontal and precuneus regions. In these two particular regions, HoM also displayed thicker cerebral cortex than other groups, whereas HoF did not differ from HeF. In addition, in HoM the parietal Cth showed "sex-reversed" values, not observed in HoF. Homosexual orientation seems associated with a less pronounced sexual differentiation of white matter tracts and a less pronounced functional connectivity of the self-referential networks compared to heterosexual orientation. Analyses of Cth suggest that male and female homosexuality are not simple analogues of each other and that differences from heterosexual controls are more pronounced in HoM.
Project description:The psychiatric classification of "normal" versus disordered sexual behavior has been a subject of some dispute. Although atypical sexual interests have been viewed traditionally as typically male, epidemiological data indicate its presence in both genders. We examined how gender and sexual orientation influence whether or not atypical sexual behavior is classified as a mental disorder. Mental health professionals (N?=?546) were presented with five case vignettes where subjects exhibit paraphilic behaviors; one case with psychotic symptoms served as the control condition. For each vignette we randomly changed the described subject's gender (male/female), sexual orientation (homosexual/heterosexual), and presented diagnostic criteria (fulfilled/ambiguous). Female subjects were significantly less pathologized and overall more stigmatized in terms of exhibitionistic, frotteuristic, sexual sadistic and pedophilic behavior. On the other hand, female sexual behavior that fulfilled diagnostic criteria for masochistic disorder was more pathologized. Our results demonstrate that nosologically irrelevant factors, which may be related to different sexual norms for men and women, affect clinicians' decisions regarding atypical sexuality.
Project description:Although frequently discussed in terms of sex dimorphism, the neurobiology of sexual orientation and identity is unknown. We report multimodal magnetic resonance imaging data, including cortical thickness (Cth), subcortical volumes, and resting state functional magnetic resonance imaging, from 27 transgender women (TrW), 40 transgender men (TrM), and 80 heterosexual (40 men) and 60 homosexual cisgender controls (30 men). These data show that whereas homosexuality is linked to cerebral sex dimorphism, gender dysphoria primarily involves cerebral networks mediating self-body perception. Among the homosexual cisgender controls, weaker sex dimorphism was found in white matter connections and a partly reversed sex dimorphism in Cth. Similar patterns were detected in transgender persons compared with heterosexual cisgender controls, but the significant clusters disappeared when adding homosexual controls, and correcting for sexual orientation. Instead, both TrW and TrM displayed singular features, showing greater Cth as well as weaker structural and functional connections in the anterior cingulate-precuneus and right occipito-parietal cortex, regions known to process own body perception in the context of self.