A dual-axis approach to understanding neuroendocrine development

Examining the dual hormone hypothesis in wild male mountain gorillas (Gorilla beringei beringei)

The Challenge Hypothesis is an influential framework for understanding how androgens are involved in the promotion of competitive behavior during mating-related challenges and has been tested extensively in studies across scientific disciplines. Mixed support in psychological research led scholars to develop the Dual Hormone Hypothesis as a potential path forward, which argues that glucocorticoids moderate the relationship between androgens and status-striving. In the current study, we examine the Challenge Hypothesis and the Dual Hormone Hypothesis in wild male mountain gorillas, representing the first time the latter hypothesis has been tested in a non-human primate. In a sample of 30 adult males comprising over 600 days of observation, we find some limited support for the Challenge Hypothesis. Greater daily rates of targeted aggression toward other adult males corresponded to higher fecal androgen metabolites 1-2 days following observations, though this pattern did not fully generalize to dominance rank or other competitive behaviors examined. However, we find no support for the Dual Hormone Hypothesis: neither dominance rank nor any category of competitive behavior was predicted by the interaction between androgens and glucocorticoids. We close by discussing how this initial investigation might be leveraged toward the development of an expanded Dual Hormone Hypothesis that draws on the large evidence base in primate behavioral ecology.

The neurobiological effects of childhood maltreatment on brain structure, function, and attachment

Childhood maltreatment is a risk factor for psychopathologies, and influences brain development at specific periods, particularly during early childhood and adolescence. This narrative review addresses phenotypic alterations in sensory systems associated with specific types of childhood maltreatment exposure, periods of vulnerability to the neurobiological effects of maltreatment, and the relationships between childhood maltreatment and brain structure, function, connectivity, and network architecture; psychopathology; and resilience. It also addresses neurobiological alterations associated with maternal communication and attachment disturbances, and uses laboratory-based measures during infancy and case-control studies to elucidate neurobiological alterations in reactive attachment disorders in children with maltreatment histories. Moreover, we review studies on the acute effects of oxytocin on reactive attachment disorder and maltreatment and methylation of oxytocin regulatory genes. Epigenetic changes may play a critical role in initiating or producing the atypical structural and functional brain alterations associated with childhood maltreatment. However, these changes could be reversed through psychological and pharmacological interventions, and by anticipating or preventing the emergence of brain alterations and subsequent psychopathological risks.

Autonomic brain functioning and age-related health concerns

The autonomic nervous system (ANS) regulates involuntary bodily functions such as blood pressure, heart rate, breathing, and digestion, in addition to controlling motivation and behavior. In older adults, the ANS is dysregulated, which changes the ability of the ANS to respond to physiological signals, regulate cardiovascular autonomic functionality, diminish gastric motility, and exacerbate sleep problems. For example, a decrease in heart rate variability, or the variation in the interval between heartbeats, is one of the most well-known alterations in the ANS associated with health issues, including cardiovascular diseases and cognitive decline. The inability to perform fundamental activities of daily living and compromising the physiological reactivity or motivational responses of older adults to moving toward or away from specific environmental stimuli are significant negative consequences of chronic and geriatric conditions that pose grave threats to autonomy, health, and well-being. The most updated research has investigated the associations between the action responsiveness of older adults and the maintenance of their physiological and physical health or the development of mental and physical health problems. Once autonomic dysfunction may significantly influence the development of different age-related diseases, including ischemic stroke, cardiovascular disease, and autoimmune diseases, this review aimed to assess the relationship between aging and autonomic functions. The review explored how motivational responses, physiological reactivity, cognitive processes, and lifelong developmental changes associated with aging impact the ANS and contribute to the emergence of health problems.

Relations of Lifetime Perceived Stress and Basal Cortisol With Hippocampal Volume Among Healthy Adolescents and Those at Clinical High Risk for Psychosis: A Structural Equation Modeling Approach

BACKGROUND

Hippocampal volume (HV) is sensitive to environmental influences. Under normative conditions in humans, HV increases linearly into childhood and asymptotes in early adulthood. Studies of humans and nonhuman animals have provided evidence of inverse relationships between several measures of stress and HV.

METHODS

Using structural equation modeling, this study aimed to characterize the relationships of age, basal cortisol, biological sex, and lifetime perceived stress with bilateral HV in a sample of healthy adolescents and adolescents at clinical high risk for psychosis (CHR-P) (N = 571, 43% female; age range = 12-19.9 years). This sample included 469 individuals at CHR-P and 102 healthy comparison participants from the combined baseline cohorts of the second and third NAPLS (North American Prodrome Longitudinal Study).

RESULTS

A structural model that constrained the individual effects of basal cortisol and perceived stress to single path coefficients, and freely estimated the effects of age and biological sex in group models, optimized model fit and parsimony relative to other candidate models. Significant inverse relationships between basal cortisol and bilateral HV were observed in adolescents at CHR-P and healthy comparison participants. Significant sex differences in bilateral HV were also observed, with females demonstrating smaller HV than males in both groups.

CONCLUSIONS

Multigroup structural equation modeling revealed heterogeneity in the relationships of age and biological sex with basal cortisol, lifetime perceived stress, and bilateral HV in individuals at CHR-P and healthy comparison participants. Moreover, the findings support previous literature indicating that elevated basal cortisol is a nonspecific risk factor for reduced HV.

Examining the relation among callous-unemotional traits and cortisol, alpha-amylase, and testosterone reactivity in legal system involved young men

Elevated callous-unemotional (CU) traits (e.g., lack of empathy, deficient guilt/remorse, and shallow affect) are associated with increased antisociality and distinct patterns of cognitive and emotional functioning. Previous investigations have suggested that deficits in physiological stress responses may underlie these associations, yet few studies simultaneously examine the multiple physiological systems responsible for mounting a stress response. To clarify how individuals with and without elevated CU traits respond to acute stress, the current study examined the association between CU traits and hormones released by three systems: cortisol from the hypothalamic-pituitary-adrenal (HPA) axis, alpha-amylase from the sympathetic nervous system (SNS), and testosterone from hypothalamic-pituitary-gonadal (HPG) axis. Specifically, we used fixed effect regression modeling to examine within-individual changes in each biomarker across the administration of a standardized laboratory stressor (Trier Social Stress Test) in a sample of 55 justice-involved young men (Mage= 22.84). Results indicated significant within-individual changes in cortisol, alpha-amylase, and testosterone following the stressor among those with low or average CU traits. However, those with high levels of CU exhibited no significant changes in their cortisol and testosterone levels. Furthermore, individuals with high CU traits exhibit an asymmetric stress response, such that alpha-amylase and testosterone levels were not associated with changes in cortisol levels. In sum, elevated CU traits were associated with blunted cortisol and testosterone reactivity and asymmetric response to stress. Additional work is needed to determine the behavioral and treatment implications of this distinct stress response.

[Depressive Disorders in Adolescence: Current State of Studies Concerning the Microbiota-Gut-Brain Axis]

Depressive Disorders in Adolescence: Current State of Studies Concerning the Microbiota-Gut-Brain Axis Abstract. Depressive disorders increase during adolescence and often lead to significant impairment in affected individuals - despite treatment. Current research efforts aim to further investigate the pathophysiology of depression, considering the influence of gut microbiota on the gut-brain axis. The present narrative review outlines the current state of studies of the microbiota-gut-brain axis in depressive disorders as well as the direct and indirect interactions in adolescence. Besides providing promising results from animal studies, studies on the microbiota-gut-brain axis in adults suffering from depressive disorders are growing steadily. In depressed adolescents, however, the study situation is still marginal, making a recommendation for the supplementation of probiotics and prebiotics in depressed children and adolescents impossible according to the current state of research. Against the background of a very limited number of studies involving adolescents with depressive disorders, the interactive role of the microbiota-gut-brain axis in adolescent development should receive special attention in future research projects.

Profiles of diurnal cortisol and DHEA regulation among children: Associations with maltreatment experiences, symptomatology, and positive adaptation

Person-centered methods represent an important advance in the simultaneous examination of multiple indicators of neuroendocrine functioning and may facilitate a more nuanced understanding of the impact of child maltreatment on hypothalamic-pituitary-adrenal axis dysregulation. The aims of the present study were threefold: (a) identify naturally occurring patterns of diurnal cortisol and dehydroepiandrosterone (DHEA) regulation among a sample of N = 1,258 children with and without histories of maltreatment, (b) investigate which neuroendocrine profiles characterize children with exposure to maltreatment, and (c) examine which profiles are related to adaptive outcomes and symptomatology among children. Cortisol and DHEA were sampled three times per day (9 a.m., 12 p.m., and 4 p.m.) across 5 and 2 days, respectively. Four profiles of cortisol and DHEA regulation were identified. Among females, a pattern marked by high cortisol and low DHEA was associated with more pervasive maltreatment experiences. Furthermore, we found evidence of adaptive interpersonal resilience such that children with maltreatment exposure who evidenced this pattern of high cortisol and low DHEA were viewed as more likeable than maltreated children with other neuroendocrine patterns. Finally, results pointed to higher levels of internalizing symptoms among children who displayed a profile marked by average cortisol and high DHEA.

Sex and pubertal influences on the neurodevelopmental underpinnings of schizophrenia: A case for longitudinal research on adolescents

Sex is a significant source of heterogeneity in schizophrenia, with more negative symptoms in males and more affective symptoms and internalizing comorbidity in females. In this narrative review, we argue that there are likely sex differences in the pathophysiological mechanisms of schizophrenia-spectrum disorders (SZ) that originate during puberty and relate to the sex-specific impacts of pubertal maturation on brain development. Pubertal maturation might also trigger underlying (genetic or other) vulnerabilities in at-risk individuals, influencing brain development trajectories that contribute to the emergence of SZ. This review is the first to integrate links between pubertal development and neural development with cognitive neuroscience research in SZ to form and evaluate these hypotheses, with a focus on the frontal-striatal and frontal-limbic networks and their hypothesized contribution to negative and mood symptoms respectively. To test these hypotheses, longitudinal research with human adolescents is needed that examines the role of sex and pubertal development using large cohorts or high risk samples. We provide recommendations for such studies, which will integrate the fields of psychiatry, developmental cognitive neuroscience, and developmental endocrinology towards a more nuanced understanding of the role of pubertal factors in the hypothesized sex-specific pathophysiological mechanisms of schizophrenia.

A dual-system, machine-learning approach reveals how daily pubertal hormones relate to psychological well-being in everyday life

The two studies presented in this paper seek to resolve mixed findings in research linking activity of pubertal hormones to daily adolescent outcomes. In study 1 we used a series of Confirmatory Factor Analyses to compare the fit of one and two-factor models of seven steroid hormones (n = 994 participants, 8084 samples) of the HPA and HPG axes, using data from a field study (https://www.icpsr.umich.edu/web/ICPSR/studies/38180) collected over ten consecutive weekdays in a representative sample of teens starting high school. In study 2, we fit a Bayesian model to our large dataset to explore how hormone activity was related to outcomes that have been demonstrated to be linked to mental health and wellbeing (self-reports of daily affect and stress coping). Results reveal, first that a two-factor solution of adolescent hormones showed good fit to our data, and second, that HPG activity, rather than the more often examined HPA activity, was associated with improved daily affect ratios and stress coping. These findings suggest that field research, when it is combined with powerful statistical techniques, may help to improve our understanding of the relationship between adolescent hormones and daily measures of well-being.

The association between cortisol-AA coordination in response to stress, negative urgency, and antisocial behavior in an urban adult sample

Prior study has found that the interplay of the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) influences behavior problems in youth. Yet, little is known regarding this relationship in adults and traits related to the coordination of the stress systems. This study aims to extend the findings of a youth sample that the coordination between HPA and ANS, measured as cortisol and alpha-amylase (AA) respectively, was associated with antisocial behavior in adults. Additionally, this study tests whether cortisol-AA coordination was associated with a conceptually relevant trait, negative urgency. A heterogeneous sample of 124 adults (college students, active offenders, and demographically matched controls) was recruited from a southern city. Participants filled out instruments for negative urgency and antisocial behavior, completed a modified Trier Social Stress Test (mTSST), and provided four saliva samples before and after mTSST to assay for cortisol and AA. Results showed that cortisol-AA stress coordination was stronger among offenders than other groups. Cortisol-AA stress coordination was also positively associated with antisocial behavior and with negative urgency. This study found support for the interpretation that cortisol-AA stress coordination may indicate an overshooting ANS response at high emotional distress, and highlight the importance of the multisystem approach in gaining new insights into behavior research.

Psychosocial and energetic factors on human female pubertal timing: a systematized review

Childhood psychosocial stressors have been proposed to favour fast life history strategies promoting earlier puberty in females. However, studies demonstrating this association often do not elucidate causal mechanisms, nor account for greater childhood energetic availability - also known to promote rapid growth and earlier puberty. To assess the extent to which such confounding has been considered, we conducted a systematized review to identify studies examining measures of both prepubertal growth (e.g. weight, height) and psychosocial stressors (e.g. adversity, father absence) in relation to female pubertal timing. A total of 1069 non-duplicated studies were identified across five databases. Twenty studies met selection criteria for critical review following independent screening of titles, abstracts and manuscripts. Within these studies, measures indicative of rapid childhood growth were more consistently associated with earlier pubertal timing than were measures of psychosocial stress. We discuss future research directions to investigate the impact of psychosocial stress on pubertal timing more robustly, including methodological and mechanistic considerations, and contextualization of findings by socioecological environments.

Adolescent Neurodevelopment and Vulnerability to Psychosis

Adolescence is characterized by significant changes in several domains, including brain structure and function, puberty, and social and environmental factors. Some of these changes serve to increase the likelihood of psychosis onset during this period, while others may buffer this risk. This review characterizes our current knowledge regarding the unique aspects of adolescence that may serve as risk factors for schizophrenia spectrum disorders. In addition, we provide potential future directions for research into adolescent-specific developmental mechanisms that impart vulnerability to psychosis and the possibility of interventions that capitalize on adolescents' unique characteristics. Specifically, we explore the ways in which gray and white matter develop throughout adolescence in typically developing youth as well as in those with psychosis spectrum disorders. We also discuss current views on the function that social support and demands, as well as role expectations, play in risk for psychosis. We further highlight the importance of considering biological factors such as puberty and hormonal changes as areas of unique vulnerability for adolescents. Finally, we discuss cannabis use as a factor that may have a unique impact during adolescent neurodevelopment, and subsequently potentially impact psychosis onset. Throughout, we include discussion of resilience factors that may provide unique opportunities for intervention during this dynamic life stage.

Earlier age of sex and substance use initiation is associated with unique hormone profiles during social evaluative threat in Mexican American adolescents

Latinx adolescents are at a disproportional risk for poor sexual and reproductive health outcomes (STIs, adolescent pregnancy) compared to other ethnic groups. They also report high rates of alcohol and drug use that are similar to non-Hispanic White youth. The hormonal underpinnings of the emergence of sex and substance use behaviors among Latinx adolescents remain understudied however. Pubertal shifts in motivation and reward-seeking in social situations are closely tied to the emergence of risky sexual and substance use behaviors. The experience of developing earlier or later than same age peers may increase stress (cortisol) reactivity during social evaluative situations leading to more risky behavior. Further, testosterone can be responsive to social evaluative threat (SET) and is linked to status-seeking behavior, including risk-taking. The current study sought to unravel the complex relationship between cortisol and testosterone responsivity to social evaluative threat, pubertal status, and the emergence of sex and drug use among US-born Mexican-origin youth growing up in an agricultural community. Mexican American 14-year olds (N = 234, 54% female) from the Center for Health Assessment of Mothers and Children (CHAMACOS) participated in the Trier Social Stress Test. Cortisol and testosterone were assayed from saliva. At 16, youth reported on age at vaginal and oral sex initiation, and alcohol and marijuana use initiation. Hierarchical regressions examined cortisol and testosterone reactivity, and pubertal status within each sex to predict the onset of these risky behaviors. Results indicated that boys who were less developed than their same-aged peers or with lower testosterone reactivity and elevated cortisol reactivity to the TSST reported the earliest sex and substance use initiation. For girls, higher cortisol reactivity predicted earlier alcohol use initiation, and higher testosterone reactivity predicted earlier oral sex. Our results suggests it is important for health care providers to not overlook Latinx boys who may look younger in discussions about mitigating risk. Latinx girls under increased stress may be more likely to try to self-medicate with alcohol, and potentially other drugs.

Reconsidering the role of sex hormones in psychopathy development: Estrogen and psychopathy among male justice-involved youth

Prominent theory suggests that factor one psychopathic traits may develop from increased input from hormones in the hypothalamic pituitary gonadal axis (HPG; i.e., testosterone) and decreased input from the hypothalamic pituitary adrenal axis (HPA; i.e., cortisol). Although there are extensive findings connecting low cortisol to psychopathy, less support has emerged for high levels of testosterone. This study examined whether incorporating the HPG hormone, estradiol, into this model would reveal relationships in line with theory: high levels of estradiol and testosterone in combination with low levels of cortisol would inform psychopathic traits. Baseline and reactive hormone levels were measured and compared to Psychopathy Checklist-Youth Version (PCL-YV) interviews among 66 male justice-involved youth (M age = 15.73) in a Southeastern juvenile detention center. The primary findings of this study were relationships between interacting HPA and HPG axis hormones with facet one and facet two psychopathic traits. Specifically, psychopathy total scores, interpersonal traits, and affective traits related to estradiol and testosterone reactivity, in that psychopathy scores were more likely with decreases in hormone reactivity (i.e., change in hormone level) following a stressor. Moreover, affective traits related to reactivity in all three hormones. These findings support inclusion of estradiol in neurobiological models of psychopathy and consideration of the individual components of psychopathy. This study adds to the growing body of research supporting interactions between variations in functioning of the HPA and HPG axes in relation to psychopathy.

Longitudinal effects of family psychopathology and stress on pubertal maturation and hormone coupling in adolescent twins

Adolescents experience profound neuroendocrine changes, including hormone "coupling" between cortisol, testosterone, and dehydroepiandrosterone. Emerging research has only begun to elucidate the role of hormone coupling, its genetic and environmental etiology, and the extent to which coupling is impacted by gender, puberty, and family context. We included measures on parent and child mental health, parenting stress, and family conflict of 444 twin pairs and their parents across two timepoints, when youth were on average 8 and 13 years old, respectively. Structural equation models examined the impact of family context effects on coupling during adolescence. Biometric twin models were then used to probe additive genetic, shared, and non-shared environmental effects on hormone coupling. Hormones were more tightly coupled for females than males, and coupling was sensitive to parental depression and co-twin psychopathology symptoms and stress exposure in females. The association between family context and coupling varied across specific neuroendocrine measures and was largely distinct from pubertal maturation. Biometric models revealed robust shared and non-shared environmental influences on coupling. We found that family antecedents modify the strength of coupling. Environmental influences account for much of the variation on coupling during puberty. Gender differences were found in genetic influences on coupling.

Evidence for disruption of diurnal salivary cortisol rhythm in childhood obesity: relationships with anthropometry, puberty and physical activity

Background

The aim of this study was to examine the characteristics of diurnal cortisol rhythm in childhood obesity and its relationships with anthropometry, pubertal stage and physical activity.

Methods

Thirty-five children with obesity (median age: 11.80[interquartile range 10.30, 13.30] and median BMI z-score: 3.21[interquartile range 2.69, 3.71]) and 22 children with normal weight (median age: 10.85[interquartile range 8.98, 12.13] and median BMI z-score: − 0.27[interquartile range − 0.88, 0.35]) were recruited. Saliva samples were collected at 08:00, 16:00 and 23:00 h. Cortisol concentrations at 3 time points, corresponding areas under the curve (AUCs) and diurnal cortisol slope (DCS) were compared between the two groups. Anthropometric measures and pubertal stage were evaluated, and behavioural information was obtained via questionnaires.

Results

Children with obesity displayed significantly lower cortisol_08:00 (median [interquartile range]: 5.79[3.42,7.73] vs. 8.44[5.56,9.59] nmol/L, P = 0.030) and higher cortisol_23:00 (median [interquartile range]: 1.10[0.48,1.46] vs. 0.40[0.21,0.61] nmol/L, P < 0.001) with a flatter DCS (median [interquartile range]: − 0.29[− 0.49, 0.14] vs. -0.52[− 0.63, 0.34] nmol/L/h, P = 0.006) than their normal weight counterparts. The AUC increased with pubertal development (AUC_{08:00–16:00}:P = 0.008; AUC_{08:00–23:00}: P = 0.005). Furthermore, cortisol_08:00 was inversely associated with BMI z-score (β = − 0.247, P = 0.036) and waist-to-height ratio (WHtR) (β = − 0.295, P = 0.027). Cortisol_23:00 was positively associated with BMI z-score (β = 0.490, P<0.001), WHtR (β = 0.485, P<0.001) and fat mass percentage (FM%) (β = 0.464, P<0.001). Absolute values of DCS were inversely associated with BMI z-score (β = − 0.350, P = 0.009), WHtR (β = − 0.384, P = 0.004) and FM% (β = − 0.322, P = 0.019). In multivariate analyses adjusted for pubertal stage and BMI z-score, Cortisol_08:00, AUC_{08:00–16:00} and absolute values of DCS were inversely associated with the relative time spent in moderate to vigorous intensity physical activity (P < 0.05). AUC_{16:00–23:00} was positively associated with relative non-screen sedentary time and negatively associated with sleep (P < 0.05).

Conclusions

The disorder of diurnal salivary cortisol rhythm is associated with childhood obesity, which is also influenced by puberty development and physical activity. Thus, stabilizing circadian cortisol rhythms may be an important approach for childhood obesity.

Puberty drives fear learning during adolescence

Risk for adverse outcomes, including the onset of mental illness, increases during adolescence. This increase may be linked to both new exposures, such as violence at home or in the community, or to physiological changes driven by puberty. There are significant sex differences in adolescent risk, for instance, anxiety disorders are significantly more prevalent in girls than boys. Fear learning is linked to mental health and may develop during adolescence, but the role of puberty in adolescent-specific change has not yet been systematically evaluated. We conducted a longitudinal study of fear learning that tested fear-potentiated startle (FPS) in 78 children (40 girls) aged 8-16 years. Participants completed two to three visits that included a differential fear conditioning task and self-report of both pubertal status and violence exposure. We tested for effects of sex, pubertal status, and violence exposure on FPS over time with latent growth curve models. We also examined the association between FPS and later anxiety symptoms. We found significant changes in FPS to the threat cue, but not the safety cue, across visits. Higher pubertal status was significantly associated with increased FPS to threat cues at each visit, whereas sex and violence exposure were not. FPS to threat during the baseline visit also predicted later anxiety symptoms. These findings suggest that puberty drives increased fear response to threat cues similarly for girls and boys, and that this effect may not be significantly impacted by individual differences in violence exposure during early adolescence.

Hormones and human developmental plasticity

Natural selection favors the evolution of mechanisms that optimize the allocation of resources and time among competing traits. Hormones mediate developmental plasticity, the changes in the phenotype that occur during ontogeny. Despite their highly conserved functions, the flexibilities of human hormonal systems suggest a strong history of adaptation to variable environments. Physiological research on developmental plasticity has focused on the early programming effects of stress, the hypothalamus-pituitary-adrenal axis (HPAA) and the hypothalamus-pituitary-gonadal axis (HPGA) during critical periods, when the hormones produced have the strongest influence on the developing brain. Often this research emphasizes the maladaptive effects of early stressful experiences. Here we posit that the HPAA and HPAG systems in human developmental plasticity have evolved to be responsive to complex and dynamic problems associated with human sociality. The lengthy period of human offspring dependency, and its associated brain development and risks, is linked to the uniquely human combination of stable breeding bonds, extensive paternal effort in a multi-male group, extended bilateral kin recognition, grandparenting, and controlled exchange of mates among kin groups. We evaluate an evolutionary framework that integrates proximate physiological explanations with ontogeny, phylogeny, adaptive function, and comparative life history data.

The development of stress reactivity and regulation during human development

Adverse experiences during childhood can have long-lasting impacts on physical and mental health. At the heart of most theories of how these effects are transduced into health impacts is the activity of stress-mediating systems, most notably the hypothalamic-pituitary-adrenocortical (HPA) axis. Here we review the anatomy and physiology of the axis, models of stress and development, the development of the axis prenatally through adolescence, the role of experience and sensitive periods in shaping its regulation, the social regulation of the axis at different points in development, and finally conclude with suggestions for future research. We conclude that it is clear that early adversity sculpts the stress system, but we do not understand which dimensions have the most impact and at what points in early development. It is equally clear that secure attachment relationships buffer the developing stress system; however, the mechanisms of social buffering and how these may change with development are not yet clear. Another critical issue that is not understood is when and for whom adversity will result in hypo- vs hyperactivity of stress-mediating systems. These and other issues are important for advancing our understanding of how early adversity "gets under the skin" and shapes human physical and mental health.

Putting the flight in "fight-or-flight": Testosterone reactivity to skydiving is modulated by autonomic activation

Sensation-seeking (SS) involves the tendency to pursue exciting activities, potentially including risky behaviors (e.g., substance use, risky sexual behavior). Testosterone is associated with cortisol, SS, and autonomic nervous system (ANS) functioning. Testosterone reactivity/recovery during sky-diving and its relationship to cortisol response, ANS response and SS were examined. Forty-four participants provided reactive saliva samples and autonomic activity data before, during and after sky-diving and as well as basal day saliva samples. Testosterone reactivity/recovery to skydiving was significantly greater than basal day measurements. Testosterone responsivity to skydiving was predicted by increased cortisol, increased sympathetic activity (heart rate) and reduced parasympathetic activity (RMSSD). Independent of physiological effects, increased SS predicted testosterone responsivity to skydiving. These data suggest that testosterone reactivity, and its relationship to ANS responsivity, may be associated with pleasurable responses to risky/intense situations. These data may be useful in developing novel intervention strategies for risky behaviors.

Testosterone, cortisol, and status-striving personality features: A review and empirical evaluation of the Dual Hormone hypothesis

Decades of research in behavioral endocrinology has implicated the gonadal hormone testosterone in the regulation of mating effort, often expressed in primates in the form of aggressive and/or status-striving behavior. Based on the idea that neuroendocrine axes influence each other, recent work among humans has proposed that links between testosterone and indices of status-striving are rendered conditional by the effects of glucocorticoids. The Dual Hormone hypothesis is one particular instance of this argument, predicting that cortisol blocks the effects of testosterone on dominance, aggression, and risk-taking in humans. Support for the Dual Hormone hypothesis is wide-ranging, but considerations of theoretical ambiguity, null findings, and low statistical power pose problems for interpreting the published literature. Here, we contribute to the development of the Dual Hormone hypothesis by (1) critically reviewing the extant literature-including p-curve analyses of published findings; and, (2) "opening the file drawer" and examining relationships between testosterone, cortisol, and status-striving personality features in seven previously published studies from our laboratories (total N = 718; median N per feature = 318) that examined unrelated predictions. Results from p-curve suggest that published studies have only 16% power to detect effects, while our own data show no robust interactions between testosterone and cortisol in predicting status-striving personality features. We discuss the implications of these results for the Dual Hormone hypothesis, limitations of our analyses, and the development of future research.

Neural correlates of depression in women across the reproductive lifespan - An fMRI review

INTRODUCTION

Depressive disorders in women emerge largely during transitions in their reproductive aging cycle, which can be attributed to internal endocrine possesses that affect emotion-associated brain circuits. A review was performed to outline the neural basis in depression during female puberty, premenstrual dysphoric disorder (PMDD), postpartum depression disorder (PPD) and perimenopausal depression disorder.

METHODS

For this review, Web of science, Pubmed and PsychInfo databases were searched for functional brain imaging studies addressing reproductive cycle-related mood disorder. The results are summarized and discussed within a broader theoretical framework of major depression disorder (MDD) to determine how reproductive-sensitive phases contribute to affective symptoms and how they relate to the neurobiology of MDD.

RESULTS

Neural activation patterns of all depressive disorders related to female reproductive cycle, except for puberty depression, differ from these observed in MDD. While the PMDD results are widely divergent, the activation patterns in PPD show general hypoactivation in all respects.

LIMITATIONS

Systematic comparisons between the diverse depression disorders are impeded by the heterogeneous experimental protocols used on different samples, reproductive aging stages and depression types.

CONCLUSION

Given that hormonal fluctuations strongly influence the development of a reproductive cycle-related depression, it is possible that the hormonal and neural patterns are indicative of distinct mood disorder with phase specific biotypes, that only show behavioral similarities to MDD. Understanding the similarities and differences in the neural functioning of female cycle-related mood disorders evaluated against MDD might help elucidate the role of neuroendocrine involvement in development of depression in women, and potentially facilitate the search for prevention and treatment approaches for women' reproductive-related depressions.

Is adolescence the missing developmental link in Microbiome-Gut-Brain axis communication?

Gut microbial research has recently opened new frontiers in neuroscience and potentiated novel therapies for mental health problems (Mayer, et al., 2014). Much of our understanding of the gut microbiome's role in brain function and behavior, however, has been largely derived from research on nonhuman animals. Even less is known about how the development of the gut microbiome influences critical periods of neural and behavioral development, particularly adolescence. In this review, we first discuss why the gut microbiome has become increasingly relevant to developmental cognitive neuroscience and provide a synopsis of the known connections of the gut microbiome with social-affective brain function and behavior, specifically highlighting human developmental work when possible. We then focus on adolescence, a key period of neurobiological and social-affective development. Specifically, we review the links between the gut microbiome and six overarching domains of change during adolescence: (a) social processes, (b) motivation and behavior, (c) neural development, (d) cognition, (e) neuroendocrine function, and (f) physical health and wellness. Using a developmental science perspective, we summarize key changes across these six domains to underscore the promise for the gut microbiome to bidirectionally influence and transform adolescent development.

The impact of the Wenchuan earthquake on early puberty: a natural experiment

Background

The factors influencing pubertal timing have gained much attention due to a secular trend toward earlier pubertal onset in many countries. However, no studies have investigated the association between the Great earthquake and early puberty. We aimed to assess whether the Wenchuan earthquake is associated with early puberty, in both boys and girls.

Methods

We used data from two circles of a survey on reproductive health in China to explore the impact of the Wenchuan earthquake on early puberty , and a total of 9,785 adolescents (4,830 boys, 49.36%) aged 12-20 years from 29 schools in eight provinces were recruited. Wenchuan earthquake exposure was defined as those Sichuan students who had not experienced oigarche/menarche before May 12, 2008. Early puberty was identified as a reported onset of oigarche/menarche at 11 years or earlier. We tested the association between the Wenchuan earthquake and early puberty in boys and girls. Then, subgroup analysis stratified by the age at earthquake exposure also was performed.

Results

In total, 8,883 adolescents (4,543 boys, 51.14%) with a mean (SD) age of 15.13 (1.81) were included in the final sample. In general, children exposed to the earthquake had three times greater risk of early puberty (boys, RR [95% CI] = 3.18 [2.21-4.57]; girls: RR [95%CI] =3.16 [2.65-3.78]). Subgroup analysis showed that the adjusted RR was 1.90 [1.19-3.03] for boys and 2.22 [1.75-2.80] for girls. Earthquake exposure predicted almost a fourfold (RR [95%CI] = 3.91 [1.31-11.72]) increased risk of early puberty in preschool girls, whereas the increase was about twofold (RR [95%CI] = 2.09 [1.65-2.64]) in schoolgirls. Among boys, only older age at earthquake exposure was linked to early puberty (RR [95%CI] = 1.93 [1.18-3.16]).

Conclusions

Wenchuan earthquake exposure increased the risk of early puberty in boys and girls, and preschoolers were more at risk than schoolchildren. The implications are relevant to support policies for those survivors, especially children, to better rebuild after disasters.

Dynamics of body time, social time and life history at adolescence

Recent opposing trends towards earlier physical maturation and later social maturation present a conundrum of apparent biological-social mismatch. Here we use life history analysis from evolutionary ecology to identify forces that drive these shifts. Together with findings in developmental science, our life history analysis indicates that adolescence is a distinctive period for biological embedding of culture. Ethnographic evidence shows that mass education is a novel feature of the globalizing cultural configurations of adolescence, which are driven by transformations in labour, livelihood and lifestyle. Evaluation of the life history trade-offs and sociocultural ecologies that are experienced by adolescents may offer a practical basis for enhancing their development.

Annual Research Review: Early adversity, the hypothalamic-pituitary-adrenocortical axis, and child psychopathology

BACKGROUND

Research on early adversity, stress biology, and child development has grown exponentially in recent years.

FINDINGS

We review the current evidence for the hypothalamic-pituitary-adrenocortical (HPA) axis as a stress-mediating mechanism between various forms of childhood adversity and psychopathology. We begin with a review of the neurobiology of the axis and evidence for relations between early adversity-HPA axis activity and HPA axis activity-psychopathology, as well as discuss the role of regulatory mechanisms and sensitive periods in development.

CONCLUSIONS

We call attention to critical gaps in the literature to highlight next steps in this research including focus on developmental timing, sex differences, stress buffering, and epigenetic regulation. A better understanding of individual differences in the adversity-HPA axis-psychopathology associations will require continued work addressing how multiple biological and behavioral systems work in concert to shape development.

The role of trauma in the hormonal interplay of cortisol, testosterone, and oxytocin in adolescent aggression

Although numerous studies have examined the neuroendocrinology of aggression, the findings are mixed and focused on cortisol and testosterone. We argue that past findings remain inconclusive partly because the key roles of oxytocin and trauma have not been systematically integrated yet. Oxytocin is associated with social behavior and interacts with cortisol and testosterone, whereas trauma is a crucial risk factor of aggression that strongly affects hormonal activity. In this review, we investigate the role of trauma in the hormonal interplay of cortisol, testosterone, and oxytocin in aggression during adolescence. We first discuss how these hormones interact with each other and how trauma influences these interactions and then we propose a model that highlights the role of trauma in the hormonal interplay in aggression. We suggest that the timing of trauma has a distinct effect on hormonal activity and it should be integrated into any comprehensive model. Current trauma is linked to different levels of oxytocin, cortisol, testosterone, and testosterone/cortisol ratio than childhood trauma, but this distinction is also influenced by gender and type of aggression. We conclude that in order to better understand the neuroendocrinology of aggression, it is crucial to incorporate the investigation of oxytocin and trauma in future research.

Basal cortisol's relation to testosterone changes may not be driven by social challenges

Multiple studies show a negative correlation between basal cortisol and testosterone changes in the presence of competition and social-evaluative stressors. These negative associations are proposed to be derived from psychological responses to competition and social-evaluative stress. However, we argue that the association between basal cortisol and testosterone change may instead be a statistical consequence of positively associated variables. In this paper, we present a mathematical rationale for this alternative explanation and examples from two studies that are consistent with this alternative explanation. Both studies show that the associations between basal cortisol and testosterone change have covariance patterns consistent with this alternative possibility. We conclude that the often-found positive association between basal cortisol and basal testosterone opens the door for alternative explanations of the basal cortisol-testosterone change association rooted in the patterns of associations between hormones measured over time. We also suggest future research directions and methods for testing alternative explanations.

Social evaluative threat with verbal performance feedback alters neuroendocrine response to stress

Laboratory stress tasks such as the Trier Social Stress Test (TSST) have provided a key piece to the puzzle for how psychosocial stress impacts the hypothalamic-pituitary-adrenal axis, other stress-responsive biomarkers, and ultimately wellbeing. These tasks are thought to work through biopsychosocial processes, specifically social evaluative threat and the uncontrollability heighten situational demands. The present study integrated an experimental modification to the design of the TSST to probe whether additional social evaluative threat, via negative verbal feedback about speech performance, can further alter stress reactivity in 63 men and women. This TSST study confirmed previous findings related to stress reactivity and stress recovery but extended this literature in several ways. First, we showed that additional social evaluative threat components, mid-task following the speech portion of the TSST, were still capable of enhancing the psychosocial stressor. Second, we considered stress-reactive hormones beyond cortisol to include dehydroepiandrosterone (DHEA) and testosterone, and found these hormones were also stress-responsive, and their release was coupled with one another. Third, we explored whether gain- and loss-framing incentive instructions, meant to influence performance motivation by enhancing the personal relevance of task performance, impacted hormonal reactivity. Results showed that each hormone was stress reactive and further had different responses to the modified TSST compared to the original TSST. Beyond the utility of showing how the TSST can be modified with heightened social evaluative threat and incentive-framing instructions, this study informs about how these three stress-responsive hormones have differential responses to the demands of a challenge and a stressor.

Quantitative Lateral Flow Assays for Salivary Biomarker Assessment: A Review

Saliva is an emerging biofluid with a significant number of applications in use across research and clinical settings. The present paper explores the reasons why saliva has grown in popularity in recent years, balancing both the potential strengths and weaknesses of this biofluid. Focusing on reasons why saliva is different from other common biological fluids such as blood, urine, or tears, we review how saliva is easily obtained, with minimal risk to the donor, and reduced costs for collection, transportation, and analysis. We then move on to a brief review of the history and progress in rapid salivary testing, again reviewing the strengths and weaknesses of rapid immunoassays (e.g., lateral flow immunoassay) compared to more traditional immunoassays. We consider the potential for saliva as an alternative biofluid in a setting where rapid results are important. We focus the review on salivary tests for small molecule biomarkers using cortisol as an example. Such salivary tests can be applied readily in a variety of settings and for specific measurement purposes, providing researchers and clinicians with opportunities to assess biomarkers in real time with lower transportation, collection, and analysis costs, faster turnaround time, and minimal training requirements. We conclude with a note of cautious optimism that the field will soon gain the ability to collect and analyze salivary specimens at any location and return viable results within minutes.

Childhood Social Disadvantage and Pubertal Timing: A National Birth Cohort From Australia

BACKGROUND AND OBJECTIVES

Early pubertal timing is linked with a range of adverse health outcomes later. Given recent trends of earlier pubertal maturation, there is growing interest in the factors influencing pubertal timing. Socioeconomic disadvantage has been previously linked with reproductive strategies later in life. In this study, we aim to determine the association between cumulative social disadvantages in early life and early puberty in a population-based birth cohort.

METHODS

Data are from the B (baby) cohort of The Longitudinal Study of Australian Children. Children (n  =  5107) were aged 0 to 1 years when recruited in 2004 and 10 to 11 years (n  =  3764) at Wave 6 in 2015. Household socioeconomic position (SEP) and neighborhood socioeconomic disadvantage were collected at all 6 waves. Trajectories of disadvantage were identified through latent class models. Early puberty at Wave 6 was assessed from parental reports using an adaptation of the Pubertal Development Scale.

RESULTS

Cumulative exposure to extremely unfavorable household SEP in boys independently predicted a fourfold increase (odds ratio = 4.22, 95% confidence interval 2.27-7.86) in the rate of early puberty. In girls, the increase was twofold (odds ratio = 1.96, 95% confidence interval 1.08-3.56). We found no effect from neighborhood disadvantage once family SEP was taken into account.

CONCLUSIONS

Cumulative exposure to household socioeconomic disadvantage in early life predicts earlier pubertal timing in both boys and girls. This may represent 1 mechanism underpinning associations between early life disadvantage and poor health in later life.

Longitudinal synergies between cortisol reactivity and diurnal testosterone and antisocial behavior in young adolescents

The aims were to identify the correspondence between simultaneous, longitudinal changes in cortisol reactivity and diurnal testosterone and to test the hypothesis that cortisol reactivity and diurnal testosterone interact so as to influence antisocial behavior. Participants were 135 children and young adolescents assessed at 6-month intervals over 1 year. Upon enrollment girls were age 8, 10, or 12 years (N = 69, M = 10.06 years) and boys were age 9, 11, or 13 years (N = 66, M = 10.94 years). Assessments included Tanner staging by a nurse, cortisol reactivity (Trier Social Stress Test for Children), diurnal testosterone, and interviews and questionnaires. Growth models showed that cortisol reactivity and diurnal testosterone basal levels (intercept) and rate of change (slopes) were not related, suggesting different mechanisms of growth. Longitudinal regression analyses assessed cortisol reactivity and diurnal testosterone longitudinally. The interactions of cortisol reactivity and diurnal testosterone showed that when diurnal testosterone was low, boys with low cortisol reactivity were reported to have more behavior problems (i.e., oppositional defiant disorder symptoms and attention problems) than when testosterone was high. In addition, when diurnal testosterone was high, boys with high or moderate cortisol reactivity were significantly higher on total antisocial behavior, attention behavior problems, and oppositional defiant disorder symptoms than when testosterone was low or moderate. The results were similar but less frequent for girls. These findings advance the science of young adolescence by showing the interaction between preexisting sensitivity to stressors and the normative testosterone changes of puberty and antisocial behavior.

A comparison of salivary testosterone measurement using immunoassays and tandem mass spectrometry

Enzyme immunoassays (EIAs) are widely used to measure salivary testosterone. However, little is known about how accurately different EIAs assess testosterone, partially because estimates across various EIAs differ considerably. We compared testosterone concentrations across EIAs of three commonly used manufacturers (DRG International, Salimetrics, and IBL International) to liquid chromatography tandem mass spectrometry (LC-MS/MS). Relative to EIAs from Salimetrics and IBL International, EIAs supplied by DRG International provided the closest approximation to LC-MS/MS testosterone concentrations, followed closely by EIAs from Salimetrics, and then IBL. Additionally, EIAs tended to inflate estimates of lower testosterone concentrations in women. Examining our results and comparing them to existing data revealed that testosterone EIAs had decreased linear correspondence with LC-MS/MS in comparison to cortisol EIAs. Overall, this paper provides researchers with information to better measure testosterone in their research and more accurately compare testosterone measurements across different methods.

The Effects of Alcohol and Cigarette Consumption on Dehydroepiandrosterone (DHEA) in Rural African Americans

Objective: Rurally situated African Americans suffer from stress and drug-related health disparities. Unfortunately, research on potential mechanisms that underlie this public health problem have received limited focus in the scientific literature. This study investigated the physiological impact of nicotine and alcohol use on dehydroepiandrosterone (DHEA) functioning, a biomarker previously linked to hypothalamic-pituitary-adrenal functioning. Method: A rural sample of African American emerging adults ( n = 84) completed a battery of assessments and provided six samples of salivary DHEA at wakeup, 30 minutes postwakeup, 90 minutes postwakeup, 3:00 p.m., 3:30 p.m., and 4:30 p.m. Results: Participants had more DHEA on waking as a function of smoking greater number of cigarettes throughout the day. Although this effect was not replicated with increased levels of alcohol consumption, the interaction between cigarette and alcohol use was associated with increased levels of DHEA on waking. Conclusion: While use of a single substance (i.e., cigarettes) was related to higher DHEA and greater hypothalamic-pituitary-adrenal activation, the addition of a second substance (i.e., alcohol) shifted the individual toward the hyperactive arousal profile common within chronically stressed or challenged populations. These findings support the need to further investigate the relationship between polysubstance use and physiological functioning that may be linked to known health disparities in the African American community.

Epigenetic Effects of Cannabis Exposure

The past decade has witnessed a number of societal and political changes that have raised critical questions about the long-term impact of marijuana (Cannabis sativa) that are especially important given the prevalence of its abuse and that potential long-term effects still largely lack scientific data. Disturbances of the epigenome have generally been hypothesized as the molecular machinery underlying the persistent, often tissue-specific transcriptional and behavioral effects of cannabinoids that have been observed within one's lifetime and even into the subsequent generation. Here, we provide an overview of the current published scientific literature that has examined epigenetic effects of cannabinoids. Though mechanistic insights about the epigenome remain sparse, accumulating data in humans and animal models have begun to reveal aberrant epigenetic modifications in brain and the periphery linked to cannabis exposure. Expansion of such knowledge and causal molecular relationships could help provide novel targets for future therapeutic interventions.