High Endogenous Testosterone Levels Are Associated With Diminished Neural Emotional Control in Aggressive Police Recruits

Hormonal responses to a stress load and state anxiety, mood, tiredness, and recovery in Portuguese police cadets

Introduction

Police officers are repeatedly exposed to conditions and incidents unique to their work.

Objectives

To describe the hormonal response to a stress load (circuit fitness test) in police cadets, and to verify the association of hormone responses (cortisol and testosterone) with state anxiety, mood, tiredness, and recovery.

Methods

This is an analytical, observational, cross-sectional study with a quantitative approach. A total of 31 police cadets (all male; age 21.0 ± 4.4 years) were evaluated on February 4, 2022, at Instituto Superior de Ciências Policiais e Segurança Interna, Lisbon, Portugal, in four dimensions: morphological, fitness for police work (simulated circuit), hormonal (cortisol and testosterone responses), and psychological (anxiety, mood, stress, and recovery).

Results

We observed differences in cortisol concentration upon awakening and the reference value; a decrease in cortisol and testosterone concentrations until the time of fitness testing; and increases in cortisol and testosterone concentrations in response to completing the fitness test. Regarding the hormone response in anticipation of the fitness test, there is a direct correlation of cortisol with hostility and social stress and an inverse correlation of testosterone with conflicts/pressure, sleep quality, emotional exhaustion, and the sum of the recovery and stress scales. Regarding the hormone response to actually performing the task, a positive correlation was found between cortisol and personal acceptance and self-regulation.

Conclusions

These findings suggest that the police cadets exhibited a healthy response to the proposed stress situation. However, whether they would respond likewise in real-world scenarios is unclear.

High bioavailable testosterone levels increase the incidence of isolated REM sleep behavior disorder: Results from multivariable and network Mendelian randomization analysis

OBJECTIVES

To explore the causal relationships between sex hormone levels and incidence of isolated REM sleep behavior disorder (iRBD).

METHODS

In our study, we utilized Genome-Wide Association Studies (GWAS) data for iRBD, including 9447 samples with 1061 cases of iRBD provided by the International RBD Study Group. Initially, we conducted a two-sample univariate MR analysis to explore the impact of sex hormone-related indicators on iRBD. This was followed by the application of multivariable MR methods to adjust for other hormone levels and potential confounders. Finally, we undertook a network MR analysis, employing brain structure Magnetic Resonance Imaging (MRI) characteristics as potential mediators, to examine whether sex hormones could indirectly influence the incidence of iRBD by affecting brain structure.

RESULTS

Bioavailable testosterone (BioT) is an independent risk factor for iRBD (Odds Ratio [95 % Confidence Interval] = 2.437 [1.308, 4.539], P = 0.005, corrected-P = 0.020), a finding that remained consistent even after adjusting for other sex hormone levels and potential confounders. Additionally, BioT appears to indirectly increase the risk of iRBD by reducing axial diffusivity and increasing the orientation dispersion index in the left cingulum and cingulate gyrus.

CONCLUSIONS

Our research reveals that elevated levels of BioT contribute to the development of iRBD. However, the specific impact of BioT on different sexes remains unclear. Furthermore, high BioT may indirectly lead to iRBD by impairing normal pathways in the left cingulum and cingulate gyrus and fostering abnormal pathway formation.

Emotion recognition and regulation in males: Role of sex and stress steroids

Understanding emotions in males is crucial given their higher susceptibility to substance use, interpersonal violence, and suicide compared to females. Steroid hormones are assumed to be critical biological factors that affect and modulate emotion-related behaviors, together with psychological and social factors. This review explores whether males' abilities to recognize emotions of others and regulate their own emotions are associated with testosterone, cortisol, and their interaction. Higher levels of testosterone were associated with improved recognition and heightened sensitivity to threatening faces. In contrast, higher cortisol levels positively impacted emotion regulation ability. Indirect evidence from neuroimaging research suggested a link between higher testosterone levels and difficulties in cognitive emotion regulation. However, this notion must be investigated in future studies using different emotion regulation strategies and considering social status. The present review contributes to the understanding of how testosterone and cortisol affect psychological well-being and emotional behavior in males.

Homo temporus: Seasonal Cycles as a Fundamental Source of Variation in Human Psychology

Many animal species exhibit seasonal changes in their physiology and behavior. Yet despite ample evidence that humans are also responsive to seasons, the impact of seasonal changes on human psychology is underappreciated relative to other sources of variation (e.g., personality, culture, development). This is unfortunate because seasonal variation has potentially profound conceptual, empirical, methodological, and practical implications. Here, we encourage a more systematic and comprehensive collective effort to document and understand the many ways in which seasons influence human psychology. We provide an illustrative summary of empirical evidence showing that seasons impact a wide range of affective, cognitive, and behavioral phenomena. We then articulate a conceptual framework that outlines a set of causal mechanisms through which seasons can influence human psychology-mechanisms that reflect seasonal changes not only in meteorological variables but also in ecological and sociocultural variables. This framework may be useful for integrating many different seasonal effects that have already been empirically documented and for generating new hypotheses about additional seasonal effects that have not yet received empirical attention. The article closes with a section that provides practical suggestions to facilitate greater appreciation for, and systematic study of, seasons as a fundamental source of variation in human psychology.

Anxious individuals shift emotion control from lateral frontal pole to dorsolateral prefrontal cortex

Anxious individuals consistently fail in controlling emotional behavior, leading to excessive avoidance, a trait that prevents learning through exposure. Although the origin of this failure is unclear, one candidate system involves control of emotional actions, coordinated through lateral frontopolar cortex (FPl) via amygdala and sensorimotor connections. Using structural, functional, and neurochemical evidence, we show how FPl-based emotional action control fails in highly-anxious individuals. Their FPl is overexcitable, as indexed by GABA/glutamate ratio at rest, and receives stronger amygdalofugal projections than non-anxious male participants. Yet, high-anxious individuals fail to recruit FPl during emotional action control, relying instead on dorsolateral and medial prefrontal areas. This functional anatomical shift is proportional to FPl excitability and amygdalofugal projections strength. The findings characterize circuit-level vulnerabilities in anxious individuals, showing that even mild emotional challenges can saturate FPl neural range, leading to a neural bottleneck in the control of emotional action tendencies.

Task-relevant social cues affect whole-body approach-avoidance behavior

Positively evaluated stimuli facilitate approach and negatively evaluated stimuli prompt avoidance responses, as typically measured by reaction time differences when moving a joystick toward the own body or away from it. In this study, we explore whether a whole-body response (forward and backward leaning can serve as a better indicator of approach-avoidance behavior; AA). Thirty-two subjects were presented with pictures of males and females with angry or happy facial expressions. Subjects had to perform approach or avoidance responses by leaning forward or backward, either based on the facial expression of the stimulus or the gender of the stimulus. Leaning responses were sensitive to angry faces for explicit decision cues. Here, angry facial expressions facilitated backward leaning but not when responding to the gender of the stimulus. We compare this to the established manual measure of AA and discuss our results with regard to response coding.

Trauma-induced human glucocorticoid receptor expression increases predict subsequent HPA-axis blunting in a prospective longitudinal design

One of the hallmarks of post-traumatic stress disorder (PTSD) is abnormalities in the HPA-axis. This includes alterations in its negative feedback regulation. Although altered glucocorticoid receptor (GR) mRNA expression is thought to play a crucial role herein, direct longitudinal evidence in humans is lacking to support this assumption. The current prospective longitudinal study assessed the consequence of repeated trauma exposure on GR mRNA expression from saliva samples in early-career police recruits (n = 112) by assessing them before and after trauma exposure. We did not observe a relationship between change in GR mRNA expression and development of PTSD symptom severity. However, the more traumatic events were experienced during police training the stronger GR mRNA expression was increased. Moreover, increases in GR mRNA expression were associated with blunted HPA-axis stress-reactivity at follow-up compared to baseline. This study provides the first longitudinal evidence of a dose-response relationship between trauma and human GR mRNA expression (extracted from saliva) changes; therefore, replication is warranted. Our finding might contribute a possible explanatory framework for blunted HPA-axis function associated with PTSD.

Help or punishment: acute stress moderates basal testosterone's association with prosocial behavior

The gonadal hormone testosterone is well-recognized to facilitate various behaviors for obtaining social status. A good reputation (i.e. competitive, generous, and trustworthy) is of crucial importance for acquiring high social status. It is unclear which type of reputation is preferred by individuals under the influence of testosterone. Given that the recent dual-hormone hypothesis emphasizes the modulating effect of stress (cortisol) on the influence of testosterone, it would be intriguing to test the role of stress-induced cortisol in testosterone-related reputation seeking. To test this hypothesis, we induced acute stress in 93 participants with cold pressor test (CPT) paradigm (vs. control condition), and then they were instructed to play a third-party intervention game, in which they made decisions as an uninvolved, outside the third party to punish a violator, help a victim, or do nothing. Salivary samples were obtained to assess participants' testosterone and cortisol levels. We split the testosterone concentration by median to low endogenous testosterone (LT) and high endogenous testosterone (HT). We found that HT individuals' prosocial preferences did not affect by acute stress. They were more likely to choose punishment than helping under both stress and control conditions. In contrast, individuals with low testosterone were more inclined to help than punish under control conditions. Interestingly, acute stress brought behavior patterns of LT individuals closer to those of HT individuals, that is, they reduced their helping behavior and increased the intensity of punishments. In this preliminary study on the preference inducement of testosterone for different types of prosocial behaviors, we discuss the physiological mechanism of the relationship between testosterone and reputation and the implications of these results for the dual-hormone hypothesis.HIGHLIGHTSLow testosterone (LT) individuals were more inclined to help than punish.High testosterone (HT) individuals were more inclined to punish than help.The HT individuals' preferences for prosocial types were not affected by acute stress.Acute stress brought the behavior patterns of LT individuals closer to those of HT individuals.

Anterior prefrontal brain activity during emotion control predicts resilience to post-traumatic stress symptoms

Regulating social emotional actions is essential for coping with life stressors and is associated with control by the anterior prefrontal cortex (aPFC) over the amygdala. However, it remains unclear to what extent prefrontal emotion regulation capacities contribute to resilience against developing post-traumatic stress disorder (PTSD) symptoms. Here, 185 police recruits who experienced their core trauma in the line of duty participated in a prospective longitudinal study. Pre- and post-trauma, they performed a well-established functional magnetic resonance imaging (fMRI) approach-avoidance task, mapping impulsive and controlled emotional actions. Higher baseline aPFC, dorsal and medial frontal pole activity was related to lower PTSD symptoms after trauma exposure. aPFC activity predicted symptom development over and above self-reported and behavioural measures. Trauma exposure, but not trauma symptoms, predicted amygdala activation at follow-up. These findings suggest that prefrontal emotion regulation activity predicts increased resilience against developing post-traumatic stress symptoms and may provide fruitful starting points for prediction and intervention studies.

Developmental variation in testosterone:cortisol ratio alters cortical- and amygdala-based cognitive processes

Testosterone (T) and cortisol (C) are the end products of neuroendocrine axes that interact with the process of shaping brain structure and function. Relative levels of T:C (TC ratio) may alter prefrontal-amygdala functional connectivity in adulthood. What remains unclear is whether TC-related effects are rooted to childhood and adolescence. We used a healthy cohort of 4-22-year-olds to test for associations between TC ratios, brain structure (amygdala volume, cortical thickness (CTh), and their coordinated growth), as well as cognitive and behavioral development. We found greater TC ratios to be associated with the growth of specific brain structures: 1) parietal CTh; 2) covariance of the amygdala with CTh in visual and somatosensory areas. These brain parameters were in turn associated with lower verbal/executive function and higher spatial working memory. In sum, individual TC profiles may confer a particular brain phenotype and set of cognitive strengths and vulnerabilities, prior to adulthood.

Testosterone Associations With Parents' Child Abuse Risk and At-Risk Parenting: A Multimethod Longitudinal Examination

The current investigation considered salivary testosterone as a potential biomarker of physical child abuse risk. Parents enrolled in a prospective, longitudinal, multimethod study beginning prenatally provided saliva when their toddlers were 18 months old. Mothers and fathers self-reported on their empathy, frustration tolerance, and child abuse risk, as well as completing analog tasks of frustration intolerance and child abuse risk and participating in structured parent-child interactions. In contrast to mothers, fathers' higher testosterone levels were associated with increased child abuse risk, less observed positive parenting, more observed negative parenting, and an analog task of frustration intolerance; such findings were reflected across time. Further, fathers' socioeconomic status moderated the association between testosterone levels and abuse risk. No evidence of partner effects was observed in dyadic analyses. The current findings suggest that higher testosterone levels reflect an increased likelihood that paternal physically abusive behavior may be expressed.

Human Lateral Frontal Pole Contributes to Control over Emotional Approach-Avoidance Actions

Regulation of emotional behavior is essential for human social interactions. Recent work has exposed its cognitive complexity, as well as its unexpected reliance on portions of the anterior PFC (aPFC) also involved in exploration, relational reasoning, and counterfactual choice, rather than on dorsolateral and medial prefrontal areas involved in several forms of cognitive control. This study anatomically qualifies the contribution of aPFC territories to the regulation of prepotent approach-avoidance action tendencies elicited by emotional faces, and explores a possible structural pathway through which this emotional action regulation might be implemented. We provide converging evidence from task-based fMRI, diffusion-weighted imaging, and functional connectivity fingerprints for a novel neural element in emotional regulation. Task-based fMRI in human male participants (N = 40) performing an emotional approach-avoidance task identified aPFC territories involved in the regulation of action tendencies elicited by emotional faces. Connectivity fingerprints, based on diffusion-weighted imaging and resting-state connectivity, localized those task-defined frontal regions to the lateral frontal pole (FPl), an anatomically defined portion of the aPFC that lacks a homologous counterpart in macaque brains. Probabilistic tractography indicated that 10%-20% of interindividual variation in emotional regulation abilities is accounted for by the strength of structural connectivity between FPl and amygdala. Evidence from an independent replication sample (N = 50; 10 females) further substantiated this result. These findings provide novel neuroanatomical evidence for incorporating FPl in models of control over human action tendencies elicited by emotional faces.SIGNIFICANCE STATEMENT Successful regulation of emotional behaviors is a prerequisite for successful participation in human society, as is evidenced by the social isolation and loss of occupational opportunities often encountered by people suffering from emotion regulation disorders, such as social-anxiety disorder and psychopathy. Knowledge about the precise cortical regions and connections supporting this control is crucial for understanding both the nature of computations needed to successfully traverse the space of possible actions in social situations, and the potential interventions that might result in efficient treatment of social-emotional disorders. This study provides evidence for a precise cortical region (lateral frontal pole) and a structural pathway (the ventral amygdalofugal bundle) through which a cognitively complex form of emotional action regulation might be implemented in the human brain.

Neural Control of Emotional Actions in Response to Affective Vocalizations

Social-emotional cues, such as affective vocalizations and emotional faces, automatically elicit emotional action tendencies. Adaptive social-emotional behavior depends on the ability to control these automatic action tendencies. It remains unknown whether neural control over automatic action tendencies is supramodal or relies on parallel modality-specific neural circuits. Here, we address this largely unexplored issue in humans. We consider neural circuits supporting emotional action control in response to affective vocalizations, using an approach-avoidance task known to reliably index control over emotional action tendencies elicited by emotional faces. We isolate supramodal neural contributions to emotional action control through a conjunction analysis of control-related neural activity evoked by auditory and visual affective stimuli, the latter from a previously published data set obtained in an independent sample. We show that the anterior pFC (aPFC) supports control of automatic action tendencies in a supramodal manner, that is, triggered by either emotional faces or affective vocalizations. When affective vocalizations are heard and emotional control is required, the aPFC supports control through negative functional connectivity with the posterior insula. When emotional faces are seen and emotional control is required, control relies on the same aPFC territory downregulating the amygdala. The findings provide evidence for a novel mechanism of emotional action control with a hybrid hierarchical architecture, relying on a supramodal node (aPFC) implementing an abstract goal by modulating modality-specific nodes (posterior insula, amygdala) involved in signaling motivational significance of either affective vocalizations or faces.