Persistent accelerated epigenetic ageing in a longitudinal cohort of vertically infected HIV-positive adolescents.

We have previously shown accelerated ageing in adolescents perinatally infected with HIV (PHIV +), based on discrepancies between epigenetic and chronological age. The current study examines follow-up longitudinal patterns of epigenetic ageing and the association of epigenetic ageing with cognition as well as whole brain structure changes in PHIV + and healthy controls enrolled in the Cape Town Adolescent Antiretroviral Cohort Study (CTAAC). The Illumina EPIC array was used to generate blood DNA methylation data from 60 PHIV + adolescents and 36 age-matched controls aged 9-12 years old at baseline and again at a 36-month follow-up. Epigenetic clock software estimated two measures of epigenetic age acceleration: extrinsic epigenetic accelerated ageing (EEAA) and age acceleration difference (AAD) at both time points. At follow-up, each participant completed neuropsychological testing, structural magnetic resonance imaging, and diffusion tensor imaging. At follow-up, PHIV infection remains associated with increased EEAA and AAD. Accelerated epigenetic ageing remained positively associated with viral load and negatively associated with CD4 ratio. EEAA was positively associated with whole brain grey matter volume and alterations in whole brain white matter integrity. AAD and EEAA were not associated with cognitive function within the PHIV + group. Measures of epigenetic ageing, as detected in DNA methylation patterns, remain increased in PHIV + adolescents across a 36-month period. Associations between epigenetic ageing measures, viral biomarkers, and alterations in brain micro- and macrostructure also persist at 36-month follow-up. Further study should determine if epigenetic age acceleration is associated with cognitive functional changes due to brain alterations in later life.

Shape analysis of subcortical structures in obsessive-compulsive disorder and the relationship with comorbid anxiety, depression, and medication use: A meta-analysis by the OCD Brain Imaging Consortium.

OBJECTIVE: Neuroimaging studies of obsessive-compulsive disorder (OCD) patients have highlighted the important role of deep gray matter structures. Less work has however focused on subcortical shape in OCD patients. METHODS: Here we pooled brain MRI scans from 412 OCD patients and 368 controls to perform a meta-analysis utilizing the ENIGMA-Shape protocol. In addition, we investigated modulating effects of medication status, comorbid anxiety or depression, and disease duration on subcortical shape. RESULTS: There was no significant difference in shape thickness or surface area between OCD patients and healthy controls. For the subgroup analyses, OCD patients with comorbid depression or anxiety had lower thickness of the hippocampus and caudate nucleus and higher thickness of the putamen and pallidum compared to controls. OCD patients with comorbid depression had lower shape surface area in the thalamus, caudate nucleus, putamen, hippocampus, and nucleus accumbens and higher shape surface area in the pallidum. OCD patients with comorbid anxiety had lower shape surface area in the putamen and the left caudate nucleus and higher shape surface area in the pallidum and the right caudate nucleus. Further, OCD patients on medication had lower shape thickness of the putamen, thalamus, and hippocampus and higher thickness of the pallidum and caudate nucleus, as well as lower shape surface area in the hippocampus and amygdala and higher surface area in the putamen, pallidum, and caudate nucleus compared to controls. There were no significant differences between OCD patients without co-morbid anxiety and/or depression and healthy controls on shape measures. In addition, there were also no significant differences between OCD patients not using medication and healthy controls. CONCLUSIONS: The findings here are partly consistent with prior work on brain volumes in OCD, insofar as they emphasize that alterations in subcortical brain morphology are associated with comorbidity and medication status. Further work is needed to understand the biological processes contributing to subcortical shape.

Childhood Trauma and Mental Health in the Cape Town Adolescent Antiretroviral Cohort.

This study aimed to assess the association of childhood trauma, stressful life events and HIV stigma with mental health in South African adolescents from the Cape Town Adolescent Antiretroviral Cohort (CTAAC). The Childhood Trauma Questionnaire, Life Events Questionnaire and the HIV Stigma Scale for South African Adolescents Living with HIV was used to assess childhood trauma, stressful life events and stigma in adolescents living with perinatally acquired HIV and healthy controls enrolled in the CTAAC. These measures were associated with mental health outcomes including the Beck-Youth Inventories, Child Behaviour Checklist, Columbian Impairment Scale, Childrens Motivation Scale, Conners Scale for Attention Deficit Hyperactivity Disorder using Pearson correlations and self-reported alcohol use, using Spearman-rank correlation. 63.7% of adolescents reported at least one childhood trauma on the CTQ. Significant associations were reported between CTQ measures and Beck-Youth Inventories. Emotional abuse was associated with anxiety, anger, depression and disruptive behaviour. Emotional neglect was associated with poor self-concept and disruptive behaviour. LEQ total score was significantly associated with Beck-Youth Inventories including anxiety, depression, anger and disruptive behaviour scales. HIV stigma was significantly associated with Beck-Youth Inventories including depression, anger and disruptive behaviour. Childhood trauma, stressful life events and HIV stigma in South African adolescents are associated with anxiety, depression, anger, disruptive-behaviour and poor self-concept. This study highlights the importance of enquiring about exposure to a variety of traumas, particularly those commonly experienced by South African adolescents. In addition, it is important to understand the impact of trauma exposure on each individuals mental health and functioning.

Genetic variants associated with longitudinal changes in brain structure across the lifespan.

Human brain structure changes throughout the lifespan. Altered brain growth or rates of decline are implicated in a vast range of psychiatric, developmental and neurodegenerative diseases. In this study, we identified common genetic variants that affect rates of brain growth or atrophy in what is, to our knowledge, the first genome-wide association meta-analysis of changes in brain morphology across the lifespan. Longitudinal magnetic resonance imaging data from 15,640 individuals were used to compute rates of change for 15 brain structures. The most robustly identified genes GPR139, DACH1 and APOE are associated with metabolic processes. We demonstrate global genetic overlap with depression, schizophrenia, cognitive functioning, insomnia, height, body mass index and smoking. Gene set findings implicate both early brain development and neurodegenerative processes in the rates of brain changes. Identifying variants involved in structural brain changes may help to determine biological pathways underlying optimal and dysfunctional brain development and aging.

Accelerated epigenetic aging in adolescents living with HIV is associated with altered development of brain structures.

We recently demonstrated that adolescents perinatally infected with HIV-1 (PHIV+) have accelerated aging as measured by a highly accurate epigenetic biomarker of aging known as the epigenetic clock. However, whether epigenetic age acceleration in PHIV+ impacts brain development at the macro- and microstructural levels of brain anatomy has not been studied. We report on a cross-sectional study of PHIV+ enrolled in the Cape Town Adolescent Antiretroviral Cohort (CTAAC). The Illumina Infinium Methylation EPIC array was used to generate DNA methylation data from the blood samples of 180 PHIV+ aged 9 to 12 years. The epigenetic clock software and method was used to estimate two measures, epigenetic age acceleration (AgeAccelerationResidual) and extrinsic epigenetic age acceleration (EEAA). Each participant underwent T1 structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). In order to investigate the associations of chronological age, sex, epigenetic age acceleration and treatment variables (CNS penetration effectiveness score (CPE)) of antiretroviral regimen on brain structure in PHIV+, we developed stepwise multiple regression models in R (version 3.4.3, 2017) including grey and white matter volumes, cortical thickness, cortical surface area and DTI measures of white matter microstructural integrity. The mean DNAm age (16.01 years) of the participants was higher than their mean chronological age (10.77 years). Epigenetic age acceleration contributed more to regional alterations of brain volumes, cortical thickness, cortical surface areas and neuronal microstructure than chronological age, in a range of regions. CPE positively contributed to volume of the brain stem. Understanding the drivers of epigenetic age acceleration could lead to valuable insights into structural brain alterations, and the persistence of neurocognitive disorders in seen in PHIV+ .

Physical development and mental health in South African perinatally HIV-positive adolescents on antiretroviral therapy and their caregivers with and without household food insecurity.

BACKGROUND: Perinatally acquired HIV-infected (PHIV+) adolescents have shown impairments in neurocognitive function and mental health problems compared with their peers. The contribution of food insecurity to such impairments has not been explored. OBJECTIVES: The aim of this report has been to explore the contribution of food insecurity to neurocognitive impairment and mental health problems in adolescents with perinatally-acquired HIV infection. METHOD: A total of 248 PHIV+ adolescents and healthy controls aged between 9 and 12 years completed a neuropsychological battery, the Childhood Behaviour Checklist (CBCL) and the Becks Youth Inventory. Head circumference, body mass index (BMI), height for age (HAZ), Tanner pubertal staging, albumin, haemoglobin, CD4 and viral loads were also measured. Participants' caregivers were interviewed about their mental health and household food security. T-tests were used to assess for differences in food secure and food insecure households. RESULTS: Caregivers of PHIV+ adolescents reported higher levels of depressive symptoms and household food insecurity. Increased food insecurity was associated with more behavioural problems in adolescents, as well as lower haemoglobin and albumin levels, faster processing speed and increased Tanner staging in boys. Body mass index and HAZ were not affected by food insecurity. CONCLUSION: These findings suggest that household food insecurity is associated with some altered behavioural, physical and physiological outcomes, which could complicate and compound the existing difficulties in PHIV+ households.

Global Systematic Review of Common Mental Health Disorders in Adults Living with HIV.

PURPOSE OF THE REVIEW: By reviewing the most recent common mental health disorders (CMHD) studies in people living with HIV (PLWH) (2018-2020), this review discusses the prevalence of CMHD, factors associated with CMHD in PLWH, mental health in PLWH from vulnerable groups, the impact of CMHD on HIV disease progression and adherence to antiretroviral therapy and the efficacy of different treatment approaches. RECENT FINDINGS: After screening for eligibility 142 studies were included in the final systematic review. Only 27% of studies were conducted in Sub-Saharan Africa, which carries the highest burn of HIV disease globally. Despite the well-established increased risk of CMHD in PLWH, the current prevalence remains high, with studies reporting 28%-62% of PLWH having mental health symptoms. CONCLUSION: Despite the significant challenges that CMHDs present to successful HIV treatment, there are many mental health treatments and interventions which can improve outcomes in PLWH and opportunities to task-shift and integrate mental health care with HIV care.

Alcohol use is associated with mental health problems and brain structural alterations in adolescents with perinatally acquired HIV infection on ART.

Alcohol use, presents unique challenges for HIV-1 treatment in adolescents with perinatally acquired infection. The effects of alcohol on host-virus interaction in the brain and the immune system remains understudied in this population. Adolescents with perinatally acquired HIV infection (PHIV) well established on ART, from the Cape Town Adolescent Antiretroviral Cohort who self-reported alcohol use (PHIV + alcohol) (n = 26) were compared to age matched 26 PHIV (PHIV-alcohol) and 26 healthy controls (HC) who reported no use of alcohol. Participants completed clinical investigations including highly-sensitive CRP (hs-CRP), a comprehensive neurocognitive test battery and mental health measures. In addition, we investigated the relationship between alcohol use in PHIV and diffusion tensor imaging (DTI) and structural brain magnetic resonance imaging (MRI) to determine fractional anisotropy (FA), mean diffusivity (MD), grey and white matter volumes and cortical thickness. PHIV (mean age 12,5 years; mean age of ART initiation 3.15 years) reported an occasional weekend drinking pattern of alcohol use. hs-CRP was significantly different between groups, with PHIV + alcohol higher than PHIV-alcohol and HC. General intelligence, attention, working memory, processing speed and executive function were more impaired in the PHIV + alcohol than PHIV alone, with HC having the highest scores. In addition, self-concept was significantly lower in PHIV + alcohol. The Child Behavior Checklist (CBCL) Externalizing behaviour, internalising behaviour and CBCL Total problems were significantly higher in PHIV + alcohol. FA of the superior corona radiata, superior fronto-occipital fasciculus and corpus callosum was significantly lower in PHIV + alcohol compared to PHIV-alcohol and MD of the corona radiata was significantly increased in PHIV + alcohol. The cortical thickness of the lateral orbitofrontal, middle frontal and precentral gyri were significantly lower in PHIV + alcohol compared to PHIV-alcohol and HC. In conclusion PHIV associated impairments in systemic inflammation, cognitive function, mental health and changes in brain structure may be exacerbated by alcohol use, even if only occasional use. However, the study is cross-sectional, which is not able to distinguish between cause and effect.

Accelerated epigenetic aging in adolescents from low-income households is associated with altered development of brain structures.

The relationship between cognitive performance, macro and microstructural brain anatomy and accelerated aging as measured by a highly accurate epigenetic biomarker of aging known as the epigenetic clock in healthy adolescents has not been studied. Healthy adolescents enrolled in the Cape Town Adolescent Antiretroviral Cohort Study were studied cross sectionally. The Illumina Infinium Methylation EPIC array was used to generate DNA methylation data from the blood samples of 44 adolescents aged 9 to 12 years old. The epigenetic clock software and method was used to estimate two measures, epigenetic age acceleration residual (AAR) and extrinsic epigenetic age acceleration (EEAA). Each participant underwent neurocognitive testing, T1 structural magnetic resonance imaging (MRI), and diffusion tensor imaging (DTI). Correlation tests were run between the two epigenetic aging measures and 10 cognitive functioning domains, to assess for differences in cognitive performance as epigenetic aging increases. In order to investigate the associations of epigenetic age acceleration on brain structure, we developed stepwise multiple regression models in R (version 3.4.3, 2017) including grey and white matter volumes, cortical thickness, and cortical surface area, as well as DTI measures of white matter microstructural integrity. In addition to negatively affecting two cognitive domains, visual memory (p = .026) and visual spatial acuity (p = .02), epigenetic age acceleration was associated with alterations of brain volumes, cortical thickness, cortical surface areas and abnormalities in neuronal microstructure in a range of regions. Stress was a significant predictor (p = .029) of AAR. Understanding the drivers of epigenetic age acceleration in adolescents could lead to valuable insights into the development of neurocognitive impairment in adolescents.

Cognition, Structural Brain Changes, and Systemic Inflammation in Adolescents Living With HIV on Antiretroviral Therapy.

OBJECTIVE: To investigate the association between neurocognitive impairment, neuroimaging, and systemic inflammation in perinatally infected adolescents living with HIV (PHIV) on antiretroviral therapy (ART). Systemic inflammation may be one mechanism driving neurocognitive impairment despite ART, but this has not been investigated in adolescence when the brain is undergoing rapid development. SETTING: Cape Town, South Africa. METHODS: Baseline data were drawn from the Cape Town Adolescent Antiretroviral Cohort. PHIV on ART >6 months completed a comprehensive neurocognitive test battery. Diffusion tensor imaging and structural brain magnetic resonance imaging was done to determine whole brain fractional anisotropy, mean diffusion (MD), grey and white matter volumes, and cortical thickness. We examined how neurocognitive and neurostructural measures were associated with a concurrently measured marker of systemic inflammation, high-sensitive C-reactive protein (hs-CRP). RESULTS: One hundred sixty-eight PHIV ages 9-12 years (mean CD4 980 cells/µL; 85.3% viral load <50 copies/mL) and 43 controls were included in the analysis. PHIV had similar hs-CRP (P = 0.17) to controls, after participants with hs-CRP >10 were excluded from the analysis. Forty-eight percent of the PHIV in this analysis have a neurocognitive disorder. Whole brain grey (P = 0.049) and white matter volumes (P = 0.044) were lowest in PHIV with a major neurocognitive disorder. Higher MD, was found in PHIV with a major neurocognitive disorder (P = 0.002). Among PHIV with a neurocognitive disorder, hs-CRP negatively correlated with general intelligence, visual spatial acuity, and executive function (all P = < 0.05). Whole brain MD correlated with higher hs-CRP values (P = < 0.01) in PHIV. CONCLUSIONS: A marker of systemic inflammation was associated with both neurocognitive impairment and MD increases in PHIV.

Neural responses in the pain matrix when observing pain of others are unaffected by testosterone administration in women.

There is evidence of testosterone having deteriorating effects on cognitive and affective empathic behaviour in men and women under varying conditions. However, whether testosterone influences empathy for pain has not yet been investigated. Therefore, we tested neural responses to witnessing others in pain in a within-subject placebo-controlled testosterone administration study in healthy young women. Using functional magnetic resonance imaging, we provide affirming evidence that an empathy-inducing paradigm causes changes in the activity throughout the pain circuitry, including the bilateral insula and anterior cingulate cortex. Administration of testosterone, however, did not influence these activation patterns in the pain matrix. Testosterone has thus downregulating effects on aspects of empathic behaviour, but based on these data does not seem to influence neural responses during empathy for others' pain. This finding gives more insight into the role of testosterone in human empathy.

Neural correlates of maintenance working memory, as well as relevant structural qualities, are associated with earlier antiretroviral treatment initiation in vertically transmitted HIV.

There is evidence of HIV affecting cognitive functioning across age groups, with adult studies showing related deficits in frontostriatal and hippocampal regional activity. Additionally, delayed initiation of antiretroviral treatment (ART) has been associated with poorer cognitive outcomes in HIV-infected youth. Little is known, however, of the neural correlates underlying such cognitive deficits in youth populations. We investigated maintenance working memory-related brain activity in South African HIV-infected youth and controls, and the effect of ART initiation age on underlying structures. Sixty-four perinatally infected youth (ages 9-12) and 20 controls (ages 9-13) underwent functional magnetic resonance imaging (fMRI) while completing 1-back and 0-back blocks of the N-back task. At an uncorrected p value threshold of 0.001, the HIV-infected group showed decreased activation in the left superior temporal gyrus, pre- and postcentral gyri, insula, and putamen as well as bilateral hippocampus, and mid cingulum. The HIV patients with delayed ART initiation showed less activation during processing conditions in the mid cingulum; left inferior parietal gyrus; and right inferior frontal, bilateral thalamic, and superior temporal regions. When these regions were tested for structural differences, the mid cingulum and right inferior frontal gyrus, insula, and thalamus were found to have less cortical thickness, surface area, or volume in the group with delayed ART initiation. Regional differences between HIV-infected youth and controls noted in the N-back task are consistent with impairments in structures involved in maintenance working memory. These data support earlier ART initiation in perinatally infected individuals.

Initiation of antiretroviral therapy after the critical neuronal developmental period of the second postnatal year affects white matter microstructure in adolescents living with HIV.

Rapid maturation of major white matter pathways occurs in the first 2 years of life, indicating a critical neuronal developmental period. The impact of initiating antiretroviral therapy (ART) in children perinatally infected with HIV-1, after the age of 2 years on neurocognitive functioning and white matter development in adolescence has not been studied. Forty-six adolescents who initiated ART during the first 2 years of life (< 2 years) and 79 adolescents who initiated ART after 2 years of age (> 2 years), with perinatally acquired HIV were enrolled in the Cape Town Adolescent Antiretroviral Cohort. Adolescents completed a comprehensive neurocognitive battery testing a number of cognitive domains. Diffusion tensor imaging (DTI) was done to determine fractional anisotropy (FA), mean diffusivity (MD), axial diffusion (AD), and radial diffusion (RD) in a region of interest analysis. Neurocognitive performance was similar between adolescents who initiated ART < 2 years or > 2 years. There was a trend towards attention (p = .07) and working memory (p = .05) being poorer in the group who initiated ART > 2 years. FA was lower in the > 2-year group in the superior corona radiata (p = .03), and the external capsule (p = .04). MD was higher in the > 2-year group in the cerebral peduncle (p = .02), the superior corona radiata (p = .01), and the superior fronto-occipital fasciculus (p = .03). RD was higher in the > 2-year group in the superior corona radiata (p = .02), the cerebral peduncle (p = .01), and the superior fronto-occipital fasciculus (p = .01). However, the higher AD in the > 2-year group in the superior corona radiata was not in the expected direction (p = .01). Initiation of ART after the neuronal development period of the second postnatal year is associated with white matter alterations on neuroimaging.

Effects of testosterone administration on threat and escape anticipation in the orbitofrontal cortex.

Recent evidence suggests that the steroid hormone testosterone can decrease the functional coupling between orbitofrontal cortex (OFC) and amygdala. Theoretically this decoupling has been linked to a testosterone-driven increase of goal-directed behaviour in case of threat, but this has never been studied directly. Therefore, we placed twenty-two women in dynamically changing situations of escapable and inescapable threat after a within-subject placebo controlled testosterone administration. Using functional magnetic resonance imaging (fMRI) we provide evidence that testosterone activates the left lateral OFC (LOFC) in preparation of active goal-directed escape and decouples this OFC area from a subcortical threat system including the central-medial amygdala, hypothalamus and periaqueductal gray. This LOFC decoupling was specific to threatening situations, a point that was further emphasized by an absence of such decoupling in a second experiment focused on resting-state connectivity. These results not only confirm that testosterone administration decouples the LOFC from the subcortical threat system, but also show that this is specifically the case in response to acute threat, and ultimately leads to an increase in LOFC activity when the participant prepares a goal-directed action to escape. Together these results for the first time provide a detailed understanding of functional brain alterations induced by testosterone under threat conditions, and corroborate and extend the view that testosterone prepares the brain for goal-directed action in case of threat.

Perinatally acquired HIV infection accelerates epigenetic aging in South African adolescents.

OBJECTIVE: Recent studies demonstrate that infection with the HIV-1 is associated with accelerated aging effects in adults according to a highly accurate epigenetic biomarker of aging known as epigenetic clock. However, it is not yet known whether epigenetic age acceleration occurs as early as adolescence in perinatally HIV-infected (PHIV+) youth. DESIGN: Observational study of PHIV and HIV-uninfected adolescents enrolled in the Cape Town Adolescent Antiretroviral Cohort Study. METHODS: The Illumina EPIC array was used to generate blood DNA methylation data from 204 PHIV and 44 age-matched, uninfected (HIV-) adolescents aged 9-12 years old. The epigenetic clock software and method was used to estimate two measures of epigenetic age acceleration. Each participant completed a comprehensive neuropsychological test battery upon enrollment to Cape Town Adolescent Antiretroviral Cohort. RESULTS: HIV is associated with biologically older blood in PHIV+ adolescents according to both measures of epigenetic age acceleration. One of the measures, extrinsic epigenetic age acceleration, is negatively correlated with measures of cognitive functioning (executive functioning, working memory, processing speed). CONCLUSION: Overall, our results indicate that epigenetic age acceleration in blood can be observed in PHIV+ adolescents and that these epigenetic changes accompany poorer cognitive functioning.

The neural correlates of Childhood Trauma Questionnaire scores in adults: A meta-analysis and review of functional magnetic resonance imaging studies.

Childhood maltreatment, including abuse and neglect, may have sustained effects on the integrity and functioning of the brain, alter neurophysiological responsivity later in life, and predispose individuals toward psychiatric conditions involving socioaffective disturbances. This meta-analysis aims to quantify associations between self-reported childhood maltreatment and brain function in response to socioaffective cues in adults. Seventeen functional magnetic resonance imaging studies reporting on data from 848 individuals examined with the Childhood Trauma Questionnaire were included in a meta-analysis of whole-brain findings, or a review of region of interest findings. The spatial consistency of peak activations associated with maltreatment exposure was tested using activation likelihood estimation, using a threshold of p < .05 corrected for multiple comparisons. Adults exposed to childhood maltreatment showed significantly increased activation in the left superior frontal gyrus and left middle temporal gyrus, and decreased activation in the left superior parietal lobule and the left hippocampus. Although hyperresponsivity to socioaffective cues in the amygdala and ventral anterior cingulate cortex in correlation with maltreatment severity is a replicated finding in region of interest studies, null results are reported as well. The findings suggest that childhood maltreatment has sustained effects on brain function into adulthood, and highlight potential mechanisms for conveying vulnerability to development of psychopathology.

Testosterone abolishes implicit subordination in social anxiety.

Neuro-evolutionary theories describe social anxiety as habitual subordinate tendencies acquired through a recursive cycle of social defeat and submissive reactions. If so, the steroid hormone testosterone might be of therapeutic value, as testosterone is a main force behind implicit dominance drive in many species including humans. We combined these two theories to investigate whether the tendency to submit to the dominance of others is an implicit mechanism in social anxiety (Study-1), and whether this can be relieved through testosterone administration (Study-2). Using interactive eye-tracking we demonstrate that socially anxious humans more rapidly avert gaze from subliminal angry eye contact (Study-1). We replicate this effect of implicit subordination in social anxiety in an independent sample, which is subsequently completely abolished after a single placebo-controlled sublingual testosterone administration (Study-2). These findings provide crucial evidence for hormonal and behavioral treatment strategies that specifically target mechanisms of dominance and subordination in social anxiety.

A quantitative and qualitative review of the effects of testosterone on the function and structure of the human social-emotional brain.

Social and affective research in humans is increasingly using functional and structural neuroimaging techniques to aid the understanding of how hormones, such as testosterone, modulate a wide range of psychological processes. We conducted a meta-analysis of functional magnetic resonance imaging (fMRI) studies of testosterone administration, and of fMRI studies that measured endogenous levels of the hormone, in relation to social and affective stimuli. Furthermore, we conducted a review of structural MRI i.e. voxel based morphometry (VBM) studies which considered brain volume in relation to testosterone levels in adults and in children. In the included testosterone administration fMRI studies, which consisted of female samples only, bilateral amygdala/parahippocampal regions as well as the right caudate were significantly activated by social-affective stimuli in the testosterone condition. In the studies considering endogenous levels of testosterone, stimuli-invoked activations relating to testosterone levels were noted in the bilateral amygdala/parahippocampal regions and the brainstem. When the endogenous testosterone studies were split by sex, the significant activation of the brain stem was seen in the female samples only. Significant stimuli-invoked deactivations relating to endogenous testosterone levels were also seen in the right and left amygdala/parahippocampal regions studies. The findings of the VBM studies were less consistent. In adults larger volumes in the limbic and temporal regions were associated with higher endogenous testosterone. In children, boys showed a positive correlation between testosterone and brain volume in many regions, including the amygdala, as well as global grey matter volume, while girls showed a neutral or negative association between testosterone levels and many brain volumes. In conclusion, amygdalar and parahippocampal regions appear to be key target regions for the acute actions of testosterone in response to social and affective stimuli, while neurodevelopmentally the volumes of a broader network of brain structures are associated with testosterone levels in a sexually dimorphic manner.

Neuroendocrine models of social anxiety disorder.

Social anxiety disorder (SAD) is a highly prevalent and disabling disorder with key behavioral traits of social fearfulness, social avoidance, and submissiveness. Here we argue that hormonal systems play a key role in mediating social anxiety, and so may be important in SAD. Hormonal alterations, often established early in development through the interaction between biological and psychological factors (eg, genetic predisposition x early trauma), predispose to socially fearful, avoidant, and submissive behavior. However, whereas gene variants and histories of trauma persist, hormonal systems can be remodeled over the course of life. Hormones play a key role during the periods of all sensitive developmental windows (ie, prenatal, neonatal, puberty, aging), and are capable of opening up new developmental windows in adulthood. Indeed, the developmental plasticity of our social brain, and thus of social behavior in adulthood, critically depends on steroid hormones such as testosterone and peptide hormones such as oxytocin. These steroid and peptide hormones in interaction with social experiences may have potential for reprogramming the socially anxious brain. Certainly, single administrations of oxytocin and testosterone in humans reduce socially fearful, avoidant, and submissive behavior. Such work may ultimately lead to new approaches to the treatment of SAD.

El trastorno de ansiedad social (TAS) es una patología altamente prevalente e incapatitante con características conductuales fundamentales de temor social, evitación social y sumisión. En este artículo se argumenta que el sistema hormonal juega un papel clave en la ansiedad social y esto puede ser importante en el TAS. Las alteraciones hormonales, a menudo establecidas precozmente durante el desarrollo a través de la interacción entre los factores biológicos y psicológicos (por ej. predisposición genética y trauma precoz), predisponen al temor social, la evitación y la conducta sumisa. Sin embargo, mientras persisten las variantes genéticas y las historias de traumas, los sistemas hormonales pueden ser remodelados a lo largo de la vida. Las hormonas juegan un papel clave durante todos los períodos de ventanas sensibles del desarrollo (es detir, prenatal, neonatal, puberal y envejetimiento) y son capaces de abrir nuevas ventanas del desarrollo en la adultez. De hecho, la plastitidad del desarrollo de nuestro cerebro social y por lo tanto de la conducta social en la adultez, depende de manera fundamental de las hormonas esteroidales como la testosterona y de péptides hormonales como la oxitotina. Estos esteroides y péptidos hormonales en interacción con las experiencias sociales pueden tener el potential para reprogramar el cerebro socialmente ansioso. Por tierto, las administraciones únicas de oxitotina y testosterona en humanos reducen el temor social y las conductas de evitación y sumisión. Este trabajo en último término puede conducir a nuevos enfoques para el tratamiento del TAS.

La prévalence de l'anxiété sociale, trouble handicapant, est très élevée et ses caractéristiques essentielles sont des traits comportementaux comme la peur en société, l'évitement des situations sociales et la soumission. Nous soutenons dans cet article que le système hormonal joue un rôle central dans la transmission de l'anxiété sociale et peut donc être important dans ce trouble. Les modifications hormonales, souvent précoces dans le développement en raison des interactions entre les facteurs biologiques et psychologiques (par exemple, prédisposition génétique x traumatisme précoce), prédisposent à un comportement social de peur, d'évitement et de soumission. Cependant, alors que les variantes géniques et les antécédents de traumatisme demeurent inchangés, les systèmes hormonaux peuvent être remodelés au cours de la vie. Les hormones jouent un rôle central pendant les phases sensibles du développement (par exemple, période prénatale, néonatale, puberté, vieillissement) et peuvent ouvrir de nouvelles phases de développement chez l'adulte. Effectivement, la plasticité de notre cerveau social au cours du développement et donc de notre comportement social à l'âge adulte dépend essentiellement des hormones stéroïdes comme la testostérone et des hormones peptidiques comme l'ocytotine. Ces hormones peptidiques et stéroïdes interagissant avec les expériences sociales pourraient reprogrammer le cerveau socialement anxieux. L'administration ponctuelle d'ocytocine et de testostérone chez l'homme diminue de façon certaine un comportement social de peur, d'évitement et de soumission. Un tel travail peut aboutir à de nouvelles approches thérapeutiques de l'anxiété sociale.

Acute effects of Sceletium tortuosum (Zembrin), a dual 5-HT reuptake and PDE4 inhibitor, in the human amygdala and its connection to the hypothalamus.

The South African endemic plant Sceletium tortuosum has a long history of traditional use as a masticatory and medicine by San and Khoikhoi people and subsequently by European colonial farmers as a psychotropic in tincture form. Over the past decade, the plant has attracted increasing attention for its possible applications in promoting a sense of wellbeing and relieving stress in healthy individuals and for treating clinical anxiety and depression. The pharmacological actions of a standardized extract of the plant (Zembrin) have been reported to be dual PDE4 inhibition and 5-HT reuptake inhibition, a combination that has been argued to offer potential therapeutic advantages. Here we tested the acute effects of Zembrin administration in a pharmaco-fMRI study focused on anxiety-related activity in the amygdala and its connected neurocircuitry. In a double-blind, placebo-controlled, cross-over design, 16 healthy participants were scanned during performance in a perceptual-load and an emotion-matching task. Amygdala reactivity to fearful faces under low perceptual load conditions was attenuated after a single 25 mg dose of Zembrin. Follow-up connectivity analysis on the emotion-matching task showed that amygdala-hypothalamus coupling was also reduced. These results demonstrate, for the first time, the attenuating effects of S. tortuosum on the threat circuitry of the human brain and provide supporting evidence that the dual 5-HT reuptake inhibition and PDE4 inhibition of this extract might have anxiolytic potential by attenuating subcortical threat responsivity.