Stress and the developing adolescent brain

The relationship between negative life events and cortical structural connectivity in adolescents

Adolescence is a crucial period for physical and psychological development. The impact of negative life events represents a risk factor for the onset of neuropsychiatric disorders. This study aims to investigate the relationship between negative life events and structural brain connectivity, considering both graph theory and connectivity strength. A group (n = 487) of adolescents from the IMAGEN Consortium was divided into Low and High Stress groups. Brain networks were extracted at an individual level, based on morphological similarity between grey matter regions with regions defined using an atlas-based region of interest (ROI) approach. Between-group comparisons were performed with global and local graph theory measures in a range of sparsity levels. The analysis was also performed in a larger sample of adolescents (n = 976) to examine linear correlations between stress level and network measures. Connectivity strength differences were investigated with network-based statistics. Negative life events were not found to be a factor influencing global network measures at any sparsity level. At local network level, between-group differences were found in centrality measures of the left somato-motor network (a decrease of betweenness centrality was seen at sparsity 5%), of the bilateral central visual and the left dorsal attention network (increase of degree at sparsity 10% at sparsity 30% respectively). Network-based statistics analysis showed an increase in connectivity strength in the High stress group in edges connecting the dorsal attention, limbic and salience networks. This study suggests negative life events alone do not alter structural connectivity globally, but they are associated to connectivity properties in areas involved in emotion and attention.

The excitatory-inhibitory balance as a target for the development of novel drugs to treat schizophrenia

The intricate balance between excitation and inhibition (E/I) in the brain plays a crucial role in normative information processing. Dysfunctions in the E/I balance have been implicated in various psychiatric disorders, including schizophrenia (SCZ). In particular, abnormalities in GABAergic signaling, specifically in parvalbumin (PV)-containing interneurons, have been consistently observed in SCZ pathophysiology. PV interneuron function is vital for maintaining an ideal E/I balance, and alterations in PV interneuron-mediated inhibition contribute to circuit deficits observed in SCZ, including hippocampus hyperactivity and midbrain dopamine system overdrive. While current antipsychotic medications primarily target D2 dopamine receptors and are effective primarily in treating positive symptoms, novel therapeutic strategies aiming to restore the E/I balance could potentially mitigate not only positive symptoms but also negative symptoms and cognitive deficits. This could involve, for instance, increasing the inhibitory drive onto excitatory neurons or decreasing the putative enhanced pyramidal neuron activity due to functional loss of PV interneurons. Compounds targeting the glycine site at glutamate NMDA receptors and muscarinic acetylcholine receptors on PV interneurons that can increase PV interneuron drive, as well as drugs that increase the postsynaptic action of GABA, such as positive allosteric modulators of α5-GABA-A receptors, and decrease glutamatergic output, such as mGluR2/3 agonists, represent promising approaches. Preventive strategies aiming at E/I balance also represent a path to reduce the risk of transitioning to SCZ in high-risk individuals. Therefore, compounds with novel mechanisms targeting E/I balance provide optimism for more effective and tailored interventions in the management of SCZ.

Sex-dependent effects of early life stress on network and behavioral states

Background

Adverse childhood experiences (ACEs) are associated with numerous detriments in health, including increased vulnerability to psychiatric illnesses. Early life stress (ELS) in rodents has been shown to effectively model several of the behavioral and endocrine impacts of ACEs and has been utilized to investigate the underlying mechanisms contributing to disease. However, the precise neural mechanisms responsible for mediating the impact of ELS on vulnerability to psychiatric illnesses remain largely unknown.

Methods

We use behavior, immunoassay, in vivo LFP recording, histology, and patch clamp to describe the effects of ELS on stress behaviors, endocrinology, network states, protein expression, and cellular physiology in male and female mice.

Results

We demonstrate that a murine maternal separation (MS) ELS model causes sex-dependent alterations in behavioral and hormonal responses following an acute stressor. Local field potential (LFP) recordings in the basolateral amygdala (BLA) and frontal cortex (FC) reveal similar sex-dependent alterations at baseline, in response to acute ethological stress, and during fear memory extinction, supporting a large body of literature demonstrating that these network states contribute to stress reactivity and vulnerability to psychiatric illnesses. Sex differences were accompanied by altered physiology of BLA principal neurons in males and BLA PV interneurons in females.

Conclusions

Collectively, these results implicate novel, sex-dependent mechanisms through which ACEs may impact psychiatric health, involving altered cellular physiology and network states involved in emotional processing.

Age-dependent effects of acute stress on the behavior, blood parameters, immunity, and enteric nerves of mice

The impact of stress on mental and digestive health has been extensively studied, with chronic stress being associated with various disorders. However, age-related differences in the response to acute stress, both behaviorally and physiologically, remain poorly understood. Therefore, this study aimed to develop a model to detect transient stress in mice of different ages. The stressor employed in our experiments was a restraint stress procedure, where mice were subjected to brief periods of immobilization to induce an acute stress response. Male C3H/HeN mice aged 3, 6, 12, and 30 weeks were subjected to acute restrain stress (ARS) by being placed in a 50 ml conical centrifuge tube for 15 min. Subsequently, their behavior, organ tissues, hematological parameters, cortisol concentration, and immune responses were assessed. Following ARS, the increased in time and entries into the center by the 12-week-old mice following stress. In comparison to mice of other ages, those aged 6 weeks demonstrated notable elevations in erythrocytes, platelets, hemoglobin, and hematocrit, all of which were influenced by the time-dependent changes and the recovery process of ARS. Blood corticosterone levels were substantially elevated in all age groups after ARS. Furthermore, ARS induced a notable increase in leukocytes, basophils, residential macrophages, and CD4+ T cells in all age groups except for 3-week-old mice. However, the number of monocyte-derived macrophages and CD8+ T cells did not change significantly. Additionally, mice aged 3 and 6 weeks demonstrated an increase in GFAP+ cells following ARS, whereas NeuN+ cells decreased across all ages. These results suggest that ARS has varying effects on the behavior, cortisol concentration, and quantity of blood cells as well as hepatic immune cells in mice of different ages. These age-dependent responses shed light on the complex interplay between stress and physiological systems and contribute to the broader understanding of stress-related diseases.

The associations of depressive symptoms and perceived stress with arterial health in adolescents

Cardiovascular and mental diseases are among the most important global health problems, but little is known on the associations between mental and arterial health in adolescents. Therefore, we investigated the associations of arterial health with depressive symptoms and perceived stress in adolescents. A total of 277 adolescents, 151 boys, 126 girls, aged 15-17 years participated in the study. Depressive symptoms were assessed using the Beck Depression Inventory and perceived stress by the Cohen Perceived Stress Scale. Arterial health was assessed by measures from carotid ultrasonography (carotid intima-media thickness, Young's Elastic Modulus, carotid artery distensibility, stiffness index), impedance cardiography (pulse wave velocity, cardio-ankle vascular index), and pulse contour analysis (reflection index, stiffness index). The data were analyzed using linear regression models adjusted for age and sex. Depressive symptoms or perceived stress were not associated with indices of arterial health in the whole study group (β = -0.08 to 0.09, p > 0.05), in boys (β = -0.13 to 0.10, p > 0.05) or in girls (standardized regression coefficient β = -0.16 to 0.08, p > 0.05). We found no associations of depressive symptoms and perceived stress with arterial health in adolescents. These observations suggest that the association between mental and arterial health problems develop in later life.

Hippocampal Structures Among Japanese Adolescents Before and After the COVID-19 Pandemic

Importance

Few studies have used a large-sample, longitudinal, population-based cohort study to examine whether the COVID-19 pandemic as a global major life event is associated with structural plasticity of the adolescent hippocampus.

Objective

To examine whether Japan's first state of emergency (SoE) during the COVID-19 pandemic was associated with alterations in the macrostructures and microstructures of the hippocampus during its development.

Design, Setting, and Participants

The population-neuroscience Tokyo TEEN Cohort study is a prospective cohort study with 4 consecutive waves in Tokyo, Japan. Due to the SoE, data collection was suspended between March 27, 2020, and July 30, 2020. Analyzed data, comprising 1149 brain structural scans obtained from 479 participants, of whom 336 participants had undergone 2 or more scans, were collected between October 2013 and November 2021. Data were analyzed from August 2022 to December 2023.

Exposures

Japan's first SoE (April 7 to May 25, 2020).

Main Outcomes and Measures

Hippocampal volume, 12 hippocampal subfield volumes, and 7 microstructural measures of the hippocampus.

Results

A total of 1060 brain scans from 459 participants (214 female participants [47%]) including 246 participants from wave 1 (median [IQR] age, 11.3 [11.1-11.7] years), 358 from wave 2 (median [IQR] age, 13.8 [13.3-14.5] years), 304 from wave 3 (median [IQR] age, 15.9 [15.4-16.5] years), and 152 from wave 4 (median [IQR] age, 17.9 [17.5-18.4] years) were included in the final main analysis. The generalized additive mixed model showed a significant associations of the SoE with the mean hippocampal volume (β = 102.19; 95% CI, 0.61-203.77; P = .049). The generalized linear mixed models showed the main associations of the SoE with hippocampal subfield volume (granule cell and molecular layer of the dentate gyrus: β = 18.19; 95% CI, 2.97-33.41; uncorrected P = .02; CA4: β = 12.75; 95% CI, 0.38-25.12; uncorrected P = .04; hippocampus-amygdala transition area: β = 5.67; 95% CI, 1.18-10.17; uncorrected P = .01), and fractional anisotropy (β = 0.03; 95% CI, 0.00-0.06; uncorrected P = .04).

Conclusions and Relevance

After the first SoE, a volumetric increase in the hippocampus and trend increase in 3 subfield volumes and microstructural integration of the hippocampus were observed, suggesting that the transient plasticity of the adolescent hippocampus was affected by a major life event along with the typical developmental trajectory.

Environmental stress during adolescence promotes depression-like behavior and endocrine abnormalities in rats

OBJECTIVE

To assess the ability of environmental stress (ES) during adolescence on depression-like behaviors and endocrinology in rats.

METHODS

Male and female Sprague-Dawley rats before or during puberty were divided into three groups: control group (CON), low-frequency ES group (LF), and high-frequency ES group (HF). ES included water/food deprivation and reversal of day and night. After 4 weeks of ES, the behavioral tests were performed. Plasma concentrations of hormones and peptides were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

ES induced a significant decrease in sucrose preference value in female adolescent rats but not males. In prepubertal rats, the reductions in sucrose preference upon ES were observed without a sex-specific effect. Compared with the CON group, female adolescent rats showed a significant increase, while male adolescent rats showed a significant decrease in plasma corticosterone (CORT) after ES. Also, ES significantly increased plasma leptin in female and male adolescent rats. Moreover, ES significantly increased plasma cholecystokinin (CCK), neuropeptide Y (NPY), and testosterone (TS) levels in adolescent female rats but not in males. No significant differences were found in plasma progesterone and E2 among adolescent rats. The prepubertal male rats showed significant plasma E2 and TS increase after ES, while there were no significant differences between groups in plasma CORT, leptin, CCK, NPY, and progesterone.

CONCLUSIONS

ES may cause depression-like behaviors in adolescent female rats. Our findings supplement the scientific basis for formulating strategies to treat and prevent adolescent depression.

Using the life course health development model to address pediatric mental health disparities

TOPIC

Early-life experiences, the transmission of health and disease within families, and the influence of cumulative risks as well as protective factors throughout life shape the trajectory of health, including mental health. Long-term health trajectories established early in life are influenced by biologic, social, and environmental factors. Negative trajectories may be more salient if exposures to adversity occur during critical developmental periods.

PURPOSE

The purpose of this brief is to (a) review pediatric health disparities related to depression and the intergenerational transmission of pediatric depression using a Life Course Health Development (LCHD) model and (b) provide recommendations for pediatric mental health research.

SOURCES

Peer-reviewed papers available for PubMed, CINAL, and Medline. Other sources include published books, papers, and gray materials.

CONCLUSIONS

The LCHD model is a perspective to guide and foster new scientific inquiry about the development of mental health outcomes over the life course. The model enables synthesis of mental health, nursing, and public health, linking mental health prevention, risk reduction, and treatment in children.

Screening for depression in children and adolescents in primary care or non-mental health settings: a systematic review update

BACKGROUND

The transition from childhood to adolescence is associated with an increase in rates of some psychiatric disorders, including major depressive disorder, a debilitating mood disorder. The aim of this systematic review is to update the evidence on the benefits and harms of screening for depression in primary care and non-mental health clinic settings among children and adolescents.

METHODS

This review is an update of a previous systematic review, for which the last search was conducted in 2017. We searched Ovid MEDLINE® ALL, Embase Classic+Embase, PsycINFO, Cochrane Central Register of Controlled Trials, and CINAHL on November 4, 2019, and updated on February 19, 2021. If no randomized controlled trials were found, we planned to conduct an additional search for non-randomized trials with a comparator group. For non-randomized trials, we applied a non-randomized controlled trial filter and searched the same databases except for Cochrane Central Register of Controlled Trials from January 2015 to February 2021. We also conducted a targeted search of the gray literature for unpublished documents. Title and abstract, and full-text screening were completed independently by pairs of reviewers.

RESULTS

In this review update, we were unable to find any randomized controlled studies that satisfied our eligibility criteria and evaluated the potential benefits and harms of screening for depression in children and adolescents. Additionally, a search for non-randomized trials yielded no studies that met the inclusion criteria.

CONCLUSIONS

The findings of this review indicate a lack of available evidence regarding the potential benefits and harms of screening for depression in children and adolescents. This absence of evidence emphasizes the necessity for well-conducted clinical trials to evaluate the effectiveness of depression screening among children and adolescents in primary care and non-mental health clinic settings.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020150373 .

Sex-Specific Vulnerability to Externalizing Problems: Sensitivity to Early Stress and Nucleus Accumbens Activation Over Adolescence

BACKGROUND

Exposure and sensitivity to early-life stress (ELS) are related to increased risk for psychopathology in adolescence. While cross-sectional studies have reported blunted nucleus accumbens (NAcc) activation in the context of these associations, researchers have not yet assessed the effects of ELS on developmental trajectories of activation. We examined whether trajectories are affected by stress and the moderating role of biological sex in predicting vulnerability to symptoms of psychopathology.

METHODS

Adolescents (n = 173) completed 3 assessments at 2-year intervals across puberty (ages 9-18 years). At baseline, we assessed objective ELS and stress sensitivity using the Traumatic Events Screening Inventory for Children. At all time points, we assessed NAcc activation using the Monetary Incentive Delay task and externalizing, internalizing, and total problems using the Youth Self-Report. We examined correlations between NAcc trajectories (extracted using linear mixed-effects models) with ELS and stress sensitivity and conducted multivariate regression analysis to examine the interaction of NAcc trajectories and biological sex in predicting symptoms of psychopathology.

RESULTS

Symptoms increased over adolescence. Stress sensitivity, but not objective ELS, was associated with decreasing trajectories of NAcc activation. Biological sex interacted with NAcc trajectories to predict psychopathology; boys, but not girls, with decreasing NAcc activation had more severe externalizing problems in adolescence. These findings were replicated in the putamen and caudate but not in the medial prefrontal cortex or control brain regions.

CONCLUSIONS

NAcc activation may be a sex-specific marker of externalizing problems in adolescence. Efforts to reduce stress sensitivity may help to decrease symptoms of psychopathology in adolescent boys.

Sex-specific interactions between stress axis and redox balance are associated with internalizing symptoms and brain white matter microstructure in adolescents

Adolescence is marked by the maturation of systems involved in emotional regulation and by an increased risk for internalizing disorders (anxiety/depression), especially in females. Hypothalamic-pituitary-adrenal (HPA)-axis function and redox homeostasis (balance between reactive oxygen species and antioxidants) have both been associated with internalizing disorders and may represent critical factors for the development of brain networks of emotional regulation. However, sex-specific interactions between these factors and internalizing symptoms and their link with brain maturation remain unexplored. We investigated in a cohort of adolescents aged 13-15 from the general population (n = 69) whether sex-differences in internalizing symptoms were associated with the glutathione (GSH)-redox cycle homeostasis and HPA-axis function and if these parameters were associated with brain white matter microstructure development. Female adolescents displayed higher levels of internalizing symptoms, GSH-peroxidase (GPx) activity and cortisol/11-deoxycortisol ratio than males. There was a strong correlation between GPx and GSH-reductase (Gred) activities in females only. The cortisol/11-deoxycortisol ratio, related to the HPA-axis activity, was associated with internalizing symptoms in both sexes, whereas GPx activity was associated with internalizing symptoms in females specifically. The cortisol/11-deoxycortisol ratio mediated sex-differences in internalizing symptoms and the association between anxiety and GPx activity in females specifically. In females, GPx activity was positively associated with generalized fractional anisotropy in widespread white matter brain regions. We found that higher levels of internalizing symptoms in female adolescents than in males relate to sex-differences in HPA-axis function. In females, our results suggest an important interplay between HPA-axis function and GSH-homeostasis, a parameter strongly associated with brain white matter microstructure.

Targeting Human Glucocorticoid Receptors in Fear Learning: A Multiscale Integrated Approach to Study Functional Connectivity

Fear extinction is a phenomenon that involves a gradual reduction in conditioned fear responses through repeated exposure to fear-inducing cues. Functional brain connectivity assessments, such as functional magnetic resonance imaging (fMRI), provide valuable insights into how brain regions communicate during these processes. Stress, a ubiquitous aspect of life, influences fear learning and extinction by changing the activity of the amygdala, prefrontal cortex, and hippocampus, leading to enhanced fear responses and/or impaired extinction. Glucocorticoid receptors (GRs) are key to the stress response and show a dual function in fear regulation: while they enhance the consolidation of fear memories, they also facilitate extinction. Accordingly, GR dysregulation is associated with anxiety and mood disorders. Recent advancements in cognitive neuroscience underscore the need for a comprehensive understanding that integrates perspectives from the molecular, cellular, and systems levels. In particular, neuropharmacology provides valuable insights into neurotransmitter and receptor systems, aiding the investigation of mechanisms underlying fear regulation and potential therapeutic targets. A notable player in this context is cortisol, a key stress hormone, which significantly influences both fear memory reconsolidation and extinction processes. Gaining a thorough understanding of these intricate interactions has implications in terms of addressing psychiatric disorders related to stress. This review sheds light on the complex interactions between cognitive processes, emotions, and their neural bases. In this endeavor, our aim is to reshape the comprehension of fear, stress, and their implications for emotional well-being, ultimately aiding in the development of therapeutic interventions.

The Development of Stress Reactivity and Regulation in Children and Adolescents

Adversity experienced in early life can have detrimental effects on physical and mental health. One pathway in which these effects occur is through the hypothalamic-pituitary-adrenal (HPA) axis, a key physiological stress-mediating system. In this review, we discuss the theoretical perspectives that guide stress reactivity and regulation research, the anatomy and physiology of the axis, developmental changes in the axis and its regulation, brain systems regulating stress, the role of genetic and epigenetics variation in axis development, sensitive periods in stress system calibration, the social regulation of stress (i.e., social buffering), and emerging research areas in the study of stress physiology and development. Understanding the development of stress reactivity and regulation is crucial for uncovering how early adverse experiences influence mental and physical health.

Differential Cortical Volume and Surface Morphometry in Youth With Chronic Health Conditions

Up to 1 in 3 youth in the United States have a childhood-onset chronic health condition (CHC), which can lead to neurodevelopmental disruptions in cognitive functioning and brain structure. However, the nature and extent of structural neurobiomarkers that may be consistent across a broad spectrum of CHCs are unknown. Thus, the purpose of this study was to identify potential differences in brain structure in youth with and without chronic physical health conditions (e.g., diabetes, hemophilia). Here, 49 T1 structural magnetic resonance imaging (MRI) images were obtained from youth with (n = 26) and without (n = 23) CHCs. Images were preprocessed using voxel-based morphometry (VBM) to generate whole-brain voxel-wise gray matter volume maps and whole-brain extracted estimates of cortical surface area and cortical thickness. Multi-scanner harmonization was implemented on surface-based estimates and linear models were used to estimate significant main effects of the group. We detected widespread decreases in brain structure in youth with CHCs as compared to controls in regions of the prefrontal, cingulate, and visual association areas. The insula exhibited the opposite effect, with cases having increased surface area as compared to controls. To our knowledge, these findings identify a novel structural biomarker of childhood-onset CHCs, with consistent alterations identified in gray matter of regions in the prefrontal cortex and insula involved in emotion regulation and executive function. These findings, while exploratory, may reflect an impact of chronic health stress in the adolescent brain, and suggest that more comprehensive assessment of stress and neurodevelopment in youth with CHCs may be appropriate.

Types of diabetes during pregnancy and risk of depression and anxiety in offspring from childhood to young adulthood

AIMS

To assess maternal pre-existing type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM) during pregnancy and risk of depression and anxiety from childhood to young adulthood in offspring.

MATERIALS AND METHODS

This birth cohort included singletons born during 1995-2015, followed using electronic medical records through 2020. Cox regression was used to estimate hazard ratio (HR) of depression or anxiety diagnosis during follow-up associated with in-utero exposure to maternal diabetes.

RESULTS

Among 439 590 offspring, 29 891 (6.8%) had depression and 51 918 (11.8%) had anxiety. T1D, followed by T2D and GDM requiring antidiabetes medication were associated with risk of depression and anxiety in offspring. Compared with no diabetes during pregnancy, the adjusted HRs (95% confidence interval) of depression in offspring associated with T1D, T2D or GDM requiring medications were 1.44 (1.09-1.91), 1.30 (1.15-1.47) and 1.18 (1.11-1.26) respectively; conversely, HRs were 0.97 (0.82-1.15) for T2D and 0.99 (0.94-1.04) for GDM without medications. The associations with anxiety followed similar patterns. The significant associations were observed for offspring ages 5-12 and >12-18 years and attenuated for 18-25 years.

CONCLUSION

These data suggest that the severity of diabetes (T1D vs. T2D requiring medications vs. GDM requiring medications) during pregnancy may increase the vulnerability of offspring for depression or anxiety.

Perceived social support mitigates the associations among household chaos and health and well-being in rural early adolescents

PURPOSE

Previous studies have demonstrated that early adolescents residing in chaotic households experience adverse health and well-being outcomes. However, the potential protective factors that mitigate the relationship between household chaos and early adolescents' health and well-being remain unknown. Accordingly, this study aims to investigate whether perceived social support moderates the link between household chaos and the health and well-being among Chinese rural early adolescents.

METHODS

Physical health difficulties were assessed using two measures: general health and allostatic load (AL). Mental health difficulties were measured by depression. Well-being was reflected by life satisfaction. Specifically, this study included early adolescents (N = 337; Mage  = 10.88 ± 1.36 years) from rural counties in China who reported their household chaos, perceived social support, general health, depression, and life satisfaction. AL scores were determined based on six physiological indices.

RESULTS

Household chaos exhibited a negative relationship with the general health and life satisfaction while a positive correlation with depression. Moreover, perceived social support was found to moderate the association between household chaos and these health and well-being indicators of early adolescents. Specifically, early adolescents who reported higher levels of perceived social support exhibited weaker negative connections among household chaos and their general health, depression, and life satisfaction. Furthermore, no significant relationships were observed between the adolescents' AL and household chaos, perceived social support, or their interactions.

CONCLUSIONS

Household chaos poses a significant risk to health and well-being. Furthermore, the findings indicate that perceived social support can mitigate these negative effects.

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.

Discordance Indices of Stress Sensitivity and Trajectories of Internalizing Symptoms in Adolescence

Psychiatric illness in adolescence is associated with long-term impairments, making it critical to identify predictors of adolescent psychiatric distress. Individual differences in stress sensitivity could be associated with longitudinal trajectories of internalizing symptoms. Historically, researchers have operationalized stress sensitivity by assessing either objective or subjective responses to stress. However, we posit that the relative discordance between subjective and objective responses to stress is a critical metric of stress sensitivity. We examined whether two discordance-based indices of stress sensitivity were related to one another and to trajectories of internalizing psychopathology among a sample of 101 adolescent youths (Mage = 12.80 at baseline; 55% males) across two successive stressors: the high school transition and the COVID-19 pandemic. Using latent growth curve modeling, we found that greater discordance between subjective (i.e., affective) and objective (i.e., cortisol) responses to a social-evaluative stressor was associated with higher internalizing symptoms at baseline and an accelerated symptom growth trajectory across the first year of the pandemic. In contrast, early life stress sensitivity was not associated with internalizing symptoms. Findings suggest that the discordance between objective and subjective experiences of social-evaluative stress predicts a pernicious growth trajectory of internalizing symptoms during adolescence. This work advances current methodologies, contributes to theoretical models of internalizing psychopathology, and with replication could have implications for policy and practice by identifying a key vulnerability factor that increases adolescents' psychiatric distress over time.

The age-varying effects of adolescent stress on impulsivity and sensation seeking

Adolescence is defined in part by heightened exposure and sensitivity to stressors. In a longitudinal cohort of youth at risk for substance use problems, we examined the age-varying relationship between stress exposure and traits that are central to the dual systems model. The positive associations between stress exposure, impulsivity, sensation seeking varied as function of age. Specifically, the influence of stress exposure on impulsivity strengthened during early adolescence and remained stable into early adulthood, while the influence of stress exposure on sensation seeking strengthened from early- to mid-adolescence and weakened thereafter. These findings suggest that the maturational imbalance between the capacity to regulate impulsive tendencies and sensation seeking may be exaggerated for youth who are exposed to a high number of stressors.

Early-life stress affects Mongolian gerbil interactions with conspecific vocalizations in a sex-specific manner

During development, early-life stress (ELS) impairs cognition, learning, and emotional regulation, in part by disrupting neural circuitry in regions underlying these higher-order functions. In addition, our recent work indicates that ELS also alters simple sensory perception: ELS impaired auditory perception and neural encoding of short gaps in sounds, which are essential for vocal communication. The combination of higher-order and basic sensory disruption suggests that ELS is likely to affect both the perception and interpretation of communication signals. We tested this hypothesis by measuring behavioral responses to conspecific vocalizations (those emitted by other gerbils) in ELS and untreated Mongolian gerbils. Because stress effects often differ by sex, we separately examined females and males. To induce ELS, pups were intermittently maternally separated and restrained from post-natal days (P) 9-24, a time window when the auditory cortex is most sensitive to external disruption. We measured the approach responses of juvenile (P31-32) gerbils to two types of conspecific vocalizations: an alarm call, which is emitted to alert other gerbils of a potential threat, and the prosocial contact call, which is emitted near familiar gerbils, especially after separation. Control males, Control females, and ELS females approached a speaker emitting pre-recorded alarm calls, while ELS males avoided this source, suggesting that ELS affects the response to alarm calls in male gerbils. During playback of the pre-recorded contact call, Control females and ELS males avoided the sound source, while Control males neither approached nor avoided, and ELS females approached the sound. These differences cannot be accounted for by changes in locomotion or baseline arousal. However, ELS gerbils slept more during playback, suggesting that ELS may reduce arousal during vocalization playback. Further, male gerbils made more errors than females on a measure of working memory, but the sex difference of cognition in this context may stem from novelty aversion rather than impaired memory. These data indicate that ELS influences behavioral responses to ethologically relevant communication sounds in a sex-specific manner, and are among the first to demonstrate an altered response to auditory stimuli following ELS. Such changes may arise from differences in auditory perception, cognition, or a combination of factors, and suggest that ELS may affect auditory communication in human adolescents.

Development and validation of the Dimensional Inventory of Stress and Trauma Across the Lifespan (DISTAL): A novel assessment tool to facilitate the dimensional study of psychobiological sequelae of exposure to adversity

Decades of research underscore the profound impact of adversity on brain and behavioral development. Recent theoretical models have highlighted the importance of considering specific features of adversity that may have dissociable effects at distinct developmental timepoints. However, existing measures do not query these dimensions in sufficient detail to support the proliferation of this approach. The Dimensional Inventory of Stress and Trauma Across the Lifespan (DISTAL) was developed with the aim to thoroughly and retrospectively assess the timing, severity (of exposure and reaction), type, persons involved, controllability, predictability, threat, deprivation, proximity, betrayal, and discrimination inherent in an individual's exposure to adversity. Here, we introduce this instrument, present descriptive statistics drawn from a sample of N = 187 adults who completed the DISTAL, and provide initial information about its psychometric properties. This novel measure facilitates the expansion of research focused on assessing the relative impact of exposure to key dimensions of adversity on the brain and behavior across development.

The Queensland Twin Adolescent Brain Project, a longitudinal study of adolescent brain development

We describe the Queensland Twin Adolescent Brain (QTAB) dataset and provide a detailed methodology and technical validation to facilitate data usage. The QTAB dataset comprises multimodal neuroimaging, as well as cognitive and mental health data collected in adolescent twins over two sessions (session 1: N = 422, age 9-14 years; session 2: N = 304, 10-16 years). The MRI protocol consisted of T1-weighted (MP2RAGE), T2-weighted, FLAIR, high-resolution TSE, SWI, resting-state fMRI, DWI, and ASL scans. Two fMRI tasks were added in session 2: an emotional conflict task and a passive movie-watching task. Outside of the scanner, we assessed cognitive function using standardised tests. We also obtained self-reports of symptoms for anxiety and depression, perceived stress, sleepiness, pubertal development measures, and risk and protective factors. We additionally collected several biological samples for genomic and metagenomic analysis. The QTAB project was established to promote health-related research in adolescence.

Vulnerability and resilience to cardiovascular and neuroendocrine effects of stress in adult rats with historical of chronic stress during adolescence

AIMS

This study investigated the influence of exposure to stress during adolescence in autonomic, cardiovascular, neuroendocrine and somatic changes evoked by chronic stress in adult rats.

MAIN METHODS

Animals were subjected to a 10-days protocol of repeated restraint stress (RRS, habituating) or chronic variable stress (CVS, non-habituating) during adolescence, adulthood, or repeated exposure to either RRS or CVS in adolescence and adulthood (adolescence+adulthood group). The trials to measure autonomic, cardiovascular, neuroendocrine and somatic changes in all experimental groups were performed in adulthood.

KEY FINDINGS

CVS increased basal circulating corticosterone levels and caused adrenal hypertrophy in the adolescence+adulthood group, an effect not identified in animals subjected to this stressor only in adulthood or adolescence. CVS also caused a sympathetically-mediated resting tachycardia in the adulthood group. This effect of CVS was not identified in the adolescence+adulthood group once the increased cardiac sympathetic activity was buffered by a decrease in intrinsic heart rate in these animals. Moreover, the impairment in baroreflex function observed in the adulthood group subjected to CVS was shifted to an improvement in animals subjected to repeated exposure to this stressor during adolescence and adulthood. The RRS in the adolescence+adulthood group caused a sympathetically-mediated resting tachycardia, which was not observed in the adulthood group.

SIGNIFICANCE

Our findings suggest that enduring effects of adverse events during adolescence included a vulnerability to neuroendocrine changes and a resilience to autonomic and cardiovascular dysfunctions caused by the CVS. Furthermore, results of RRS indicated a vulnerability to cardiovascular and autonomic changes evoked by homotypic stressors.

Stress in adolescence as a first hit in stress-related disease development: Timing and context are crucial

The two-hit stress model predicts that exposure to stress at two different time-points in life may increase or decrease the risk of developing stress-related disorders later in life. Most studies based on the two-hit stress model have investigated early postnatal stress as the first hit with adult stress as the second hit. Adolescence, however, represents another highly sensitive developmental window during which exposure to stressful events may affect programming outcomes following exposure to stress in adulthood. Here, we discuss the programming effects of different types of stressors (social and nonsocial) occurring during adolescence (first hit) and how such stressors affect the responsiveness toward an additional stressor occurring during adulthood (second hit) in rodents. We then provide a comprehensive overview of the potential mechanisms underlying interindividual and sex differences in the resilience/susceptibility to developing stress-related disorders later in life when stress is experienced in two different life stages.

Does Problematic Use of Social Network Mediate the Association between Bullying Victimization and Loneliness among Lebanese Adolescents?

(1) Background: Bullying victimization has been associated with several behavioral outcomes, particularly loneliness. Similarly, an increase in social network use has been identified in recent years, particularly during the COVID-19 pandemic, and has been shown to be associated with bullying and loneliness. Investigating the mediating factors of loneliness among bullied adolescents is useful for taking preventive measures in the Lebanese population. This study aims to examine the association between bullying victimization and loneliness among Lebanese adolescents while considering the indirect effect of problematic social network use. (2) Methods: We carried out a cross-sectional study, between January and April 2022, that enrolled 379 adolescent Lebanese students (64.9% females, mean age 16.07 ± 1.19 years) who were current residents of Lebanon (15 to 18 years), and were from the five governorates of Lebanon (Beirut, Mount Lebanon, North, South and Bekaa). The snowball method was applied to select our sample; an electronic copy of the questionnaire was created using the Google Forms software and an online strategy was designed to collect the data. (3) Results: Negative social comparison and addictive consequences of problematic use of social network mediated the association between bullying victimization and loneliness. Higher bullying victimization was significantly associated with higher negative social comparison and addictive consequences of problematic use of social network, which in turn were significantly associated with more loneliness. Finally, higher bullying victimization was directly significantly associated with more loneliness. (4) Conclusions: Studying the mediating factors of loneliness in bullied adolescents can improve our understanding of this topic, allowing us to propose new interventions to prevent psychological problems in adolescents. Future studies are needed to further clarify the physiological processes that underlie the associations between social triggers and loneliness during adolescence.

The resilience of adolescent male rats to acute stress-induced delayed anxiety is age-related and glucocorticoid release-dependent

Studies investigated how stressful experiences modulate physiological and behavioral responses and the consequences of stress-induced corticosterone release in anxiety-like behavior. Adolescence is crucial to brain maturation, and several neurobiological changes in this period lead individuals to increased susceptibility or resilience to aversive situations. Despite the effects of stress in adults, information about adolescents' responses to acute stress is lacking. We aimed to understand how adolescence affects acute stress responses. Male adolescent rats (30 days old) were 2 h restrained, and anxiety-like behaviors were measured immediately or 10 days after stress in the elevated plus-maze (EPM) and the light-dark box (LDB) tests. To verify the importance of CORT modulation in stress-induced anxiety, another group of rats was treated, 30 min before restraint, with metyrapone to blunt the stress-induced CORT peak and tested immediately after stress. To show that stress effects on behavior were age-dependent, another set of rats was tested in two different periods - early adolescence (30 days old) and mid-adolescence (40 days old) and were treated or not with metyrapone before the stress session and tested immediately or ten days later in the LDB test. Only early adolescent male rats were resilient to delayed anxiety-like behavior in EPM and LDB tests. Metyrapone treatment increased the rats' exploration immediately and ten days after stress. These data suggest a specific age at which adolescent rats are resilient to the delayed effects of acute restraint stress and that the metyrapone treatment has long-term behavioral consequences.

Measuring Adolescent Chronic Stress: A Review of Established Biomarkers and Psychometric Instruments

Adolescence is a period of stressful physiological and psychosocial changes. Exposure to chronic stress can cause specific structural and functional changes in an organism, which can be appraised objectively. Some of these alterations are an expected reaction of the body in its attempt to adapt to a stressful situation, while others are signs of possible disease development. The aim of this review was to present the most widely used methods of stress evaluation in adolescence research. Primary biomarkers associated with different biological systems, such as the stress hormones glucocorticoids, and catecholamines, as well as the available methods of extraction and assessment of each biomarker, are presented. This work also includes secondary outcomes, which can also provide an estimation of an individual's stress level. Also, most available psychometric instruments of stress, constructed to address specifically this period of life, are presented and discussed. In addition, this paper addresses possible confounding factors that may affect stress measurements, which should be taken under consideration when conducting stress research. To objectively evaluate stress, it is of great importance for a researcher to be familiar with the condition under examination and its representative stress indices. Adequate evaluation of adolescents with the selection of proper psychometric tests and biological markers can help design targeted interventions aiming to prevent or reverse the effects of physical and mental stressors that occur during adolescence, effects that can be carried into adulthood with detrimental consequences.

A cross-sectional study of the association between exposure to violence, intelligence, and executive function in Brazilian youths

We carried out an exploratory study of the association between exposure to violence, intelligence, and executive functions in Brazilian preadolescents. The study included 56 participants (31 males) aged 8 to 14 years old (mean = 11.3, SD = 1.0). We administered neuropsychological tests to evaluate executive functions and the Juvenile Victimization Questionnaire (JVQ) to evaluate exposure to violence. We used the following neuropsychological instruments: Wechsler Abbreviated Scale of Intelligence (WASI), Stroop Color-Word Interference task, digits subtest of the Wechsler Intelligence Scale for Children, and an N-back task. We generated a composite score from neuropsychological test scores and investigated the association of that score, and individual test scores, with exposure to violence and socioeconomic status (SES). Results suggest, first, that exposure to violence is associated with a 0.5-point lower intelligence quotient score for every reported victimization event in the Juvenile Victimization Questionnaire. Results also show that the digits backward subtest scores showed a significant negative correlation with exposure to violence (JVQ; rho = -0.29, p < 0.05); both analyses were adjusted for the level of schooling of parents or guardians, which was also found to be significantly associated with lower intelligence quotient scores. We discuss results in the light of the existing literature on the effects of exposure to violence on adolescent development, and the amounting evidence that suggests an association of exposure to violence, and of victimization, with tests that evaluate constructs of executive functions. The study struggled with low compliance from participants, and we underscore the challenges of carrying out empirical studies aimed at better understanding the development of underrepresented youths, such as those from Central and Latin America.

Adolescent social isolation shifts the balance of decision-making strategy from goal-directed action to habitual response in adulthood via suppressing the excitatory neurotransmission onto the direct pathway of the dorsomedial striatum

Adverse experience, such as social isolation, during adolescence is one of the major causes of neuropsychiatric disorders that extend from adolescence into adulthood, such as substance addiction, obsessive-compulsive disorder, and eating disorders leading to obesity. A common behavioral feature of these neuropsychiatric disorders is a shift in the balance of decision-making strategy from goal-directed action to habitual response. This study has verified that adolescent social isolation directly shifts the balance of decision-making strategy from goal-directed action to habitual response, and that it cannot be reversed by simple regrouping. This study has further revealed that adolescent social isolation induces a suppression in the excitatory neurotransmission onto the direct-pathway medium spiny neurons of the dorsomedial striatum (DMS), and that chemogenetically compensating this suppression effect shifts the balance of decision-making strategy from habitual response back to goal-directed action. These findings suggest that the plasticity in the DMS causes the shift in the balance of decision-making strategy, which would potentially help to develop a general therapy to treat the various neuropsychiatric disorders caused by adolescent social isolation. Such a study is especially necessary under the circumstances that social distancing and lockdown have caused during times of world-wide, society-wide pandemic.

Adolescents' neural reactivity to acute psychosocial stress: dysfunctional regulation habits are linked to temporal gyrus response

Mid-adolescence is a critical time for the development of stress-related disorders and it is associated with significant social vulnerability. However, little is known about normative neural processes accompanying psychosocial stress at this time. Previous research found that emotion regulation strategies critically influence the relationship between stress and the development of psychiatric symptoms during adolescence. Using functional magnetic resonance imaging (fMRI), we examined neural responses to acute stress and analyzed whether the tendency to use adaptive or maladaptive emotion regulation strategies is related to neural and autonomic stress responses. Results show large linear activation increases from low to medium to high stress levels mainly in medial prefrontal, insulae and temporal areas. Caudate and subgenual anterior cingulate cortex, neural areas related to reward and affective valuations, showed linearly decreasing activation. In line with our hypothesis, the current adolescent neural stress profile resembled social rejection and was characterized by pronounced activation in insula, angular and temporal cortices. Moreover, results point to an intriguing role of the anterior temporal gyrus. Stress-related activity in the anterior temporal gyrus was positively related to maladaptive regulation strategies and stress-induced autonomic activity. Maladaptive coping might increase the social threat and reappraisal load of a stressor, relating to higher stress sensitivity of anterior temporal cortices.

Circadian cortisol secretion in adolescent girls with conduct disorder

Severe antisocial behavior in girls, best exemplified by conduct disorder (CD), is a serious clinical and public health problem. Treatment is difficult, particularly in girls with comorbid internalizing disorders. Identifying biological correlates may help to develop new treatments or diagnostic, prognostic, or treatment response biomarkers. Based on our earlier work and research from others occurring primarily in boys with severe antisocial behavior, it is possible that abnormalities in the hypothalamic pituitary adrenal (HPA) axis circadian cortisol cycle may be associated with female CD. Additionally, research suggests that the presence of comorbid internalizing disorders may be related to differences in cortisol secretion, compared to subjects who only have CD. Our study aimed: 1) to compare the circadian cortisol cycle in 98 girls with CD, 15-16 years of age to 47 girls without any psychiatric disorder (ND) and 2) to compare the cycle in girls with CD and comorbid internalizing disorders (CD + INT) to those without such comorbidity (CD Only). Salivary cortisol was collected over 24 h during weekdays at scheduled times, with protocol adherence measures in place. Unstructured covariance pattern modeling, controlling for effects of age, social class, IQ, and awakening time was used to analyze cortisol data. CD was associated with overall lower cortisol secretion (p = 0.03), but this difference was due to a lower volume of cortisol secreted 30 min after awakening (area under the curve with respect to ground, p = 0.01). Circadian cortisol secretion was no different in the CD+INT group compared to the CD Only group (p = 0.52). Our findings need to be replicated using current consensus guidelines for the assessment of the CAR. We also suggest two new avenues of research in this field.

Trajectories of psychological stress in youth across the first year of inflammatory bowel disease diagnosis

OBJECTIVE

Youth newly diagnosed with inflammatory bowel diseases (IBD) may be physically impacted by their disease and experience increased psychological stress. Stress is known to relate to greater reported IBD symptoms, but little is known about the longitudinal experience of stress and clinical symptoms of youth newly diagnosed with IBD.

METHODS

Fifty-seven children (Mage = 14.26, range 8-17 years) diagnosed with IBD completed measures assessing psychological stress (PROMIS Psychological Stress Experiences), depressive symptoms (Children's Depression Inventory-2), and clinical disease symptoms (Self-Report Disease Activity) within 45 days of diagnosis and at 6-month and 1-year follow-ups. Group-based trajectory modeling was used to describe trajectory patterns of psychological stress over the first year of diagnosis and logistic regression identified predictors of group membership.

RESULTS

Two distinct groups of psychological stress trajectories were identified: 1) low prevalence over the first year of diagnosis (51%) and 2) moderate and increasing prevalence (49%). Membership in the moderate and increasing psychological stress group was associated with female sex and greater IBD symptoms at diagnosis.

CONCLUSION

Findings suggest roughly half of youth newly diagnosed with IBD would likely benefit from multidisciplinary assessment and intervention to promote adaptive stress management, given moderate and increasing stress levels. Future research is needed to evaluate specific intervention techniques most helpful to youth with IBD.

Sex- and exposure age-dependent effects of adolescent stress on ventral tegmental area dopamine system and its afferent regulators

Adolescent stress is a risk factor for schizophrenia. Emerging evidence suggests that age-dependent sensitive windows for childhood trauma are associated more strongly with adult psychosis, but the neurobiological basis and potential sex differences are unknown.Using in vivo electrophysiology and immunohistology in rats, we systematically compared the effects of two age-defined adolescent stress paradigms, prepubertal (postnatal day [PD] 21-30; PreP-S) and postpubertal (PD41-50; PostP-S) foot-shock and restraint combined stress, on ventral tegmental area (VTA) dopaminergic activity, pyramidal neuron activity in the ventral hippocampus (vHipp) and the basolateral amygdala (BLA), corticoamygdalar functional inhibitory control, and vHipp and BLA parvalbumin interneuron (PVI) impairments. These endpoints were selected based on their well-documented roles in the pathophysiology of psychosis.Overall, we found distinct sex- and exposure age-dependent stress vulnerability. Specifically, while males were selectively vulnerable to PreP-S-induced adult VTA dopamine neuron and vHipp hyperactivities, females were selectively vulnerable to PostP-S. These male selective PreP-S effects were correlated with stress-induced aberrant persistent BLA hyperactivity, dysfunctional prefrontal inhibitory control of BLA neurons, and vHipp/BLA PVI impairments. In contrast, female PostP-S only produced vHipp PVI impairments in adults, with the BLA structure and functions largely unaffected.Our results indicated distinct adolescent-sensitive periods during which stress can sex-dependently confer maximal risks to corticolimbic systems to drive dopamine hyperactivity, which provide critical insights into the neurobiological basis for sex-biased stress-related psychopathologies emphasizing but not limited to schizophrenia. Furthermore, our work also provides a framework for future translational research on age-sensitive targeted interventions.

Aversive memory reactivation: A possible role for delta oscillations in the hippocampus-amygdala circuit

Memory labilization, the process by which memories become susceptible to update, is essential for memory reconsolidation and has been a target for novel therapies for traumatic memory-associated disorders. Maternal separation (MS) in male rats produced memories resistant to labilization in adulthood. Based on previous results, we hypothesized that temporal desynchronization between the dorsal hippocampus (DHc) and the basolateral amygdala (BLA), during memory retrieval, could be responsible for this impairment. Our goal was to investigate possible differences in oscillatory activity and synchrony between the DHc and BLA during fear memory reactivation, between MS and non-handled (NH) rats. We used male adult Wistar rats, NH or MS, with electrodes for local field potential (LFP) recordings implanted in the DHc and BLA. Animals were submitted to aversive memory reactivation by exposure to the conditioned context (Reat) or to pseudo-reactivation in a neutral context (pReat), and LFP was recorded. Plasticity markers linked to reconsolidation were evaluated one hour after reactivation. The power of delta oscillations and DHc-BLA synchrony in Reat animals was increased, during freezing. Besides, delta modulation of gamma oscillations amplitude in the BLA was associated with the increase in DHc Zif268 levels, an immediate early gene specifically associated with reconsolidation. Concerning early life stress, we found lower power of delta and strength of delta-gamma oscillations coupling in MS rats, compared to NH, which could explain the low Zif268 levels in a subgroup of MS animals. These results suggest a role for delta oscillations in memory reactivation that should be further investigated.

War exposure, post-traumatic stress symptoms and hair cortisol concentrations in Syrian refugee children

Altered secretion of cortisol, the primary effector of the hypothalamus-pituitary-adrenal axis, has been proposed as a means by which traumatic experiences compromise later mental health. However, despite the popularity of cortisol as a potential biomarker for stress and adversity, findings are inconsistent, and little is known about the impact of war-related trauma on stress physiology of children and adolescents. Here we aimed to evaluate the relationships between war exposure, current living conditions, hair cortisol concentrations (HCC) and post-traumatic stress disorder (PTSD) symptoms in a large cohort of Syrian refugee children and adolescents (6-18 years) and their caregiver. This longitudinal observational study assessed Syrian refugee children and adolescents in two waves, 1 year apart, within informal tented settlements in Lebanon. The relationships between war exposure, time since leaving Syria, PTSD symptoms and HCC were investigated using linear mixed-model regression utilising both waves of data collected (Y1: N = 1574, Y2: N = 923). Hair cortisol concentration was positively, but weakly associated with the number of war-related events experienced. This was limited to those who were at least 12 years old at the time of war exposure. Conversely, HCC decreased with time since leaving Syria. HCC was also associated with PTSD symptoms but not with the quality of their current living conditions. This study revealed that changes to hypothalamic-pituitary-adrenal axis activity may accompany both earlier war exposure and current PTSD symptoms in children and adolescents. Additionally, early adolescence may be a particularly sensitive time in terms of trauma-related changes to the hypothalamic-pituitary-adrenal axis.

Stress-induced myelin damage in the hippocampal formation in a rat model of depression

BACKGROUND

According to previous studies, myelin damage may be involved in the occurrence of depression. However, to date, no study has quantitatively investigated the changes in myelinated fibers and myelin sheaths in the hippocampal formation (HF) and hippocampal subfields in the context of depression.

METHODS

Male Sprague-Dawley (SD) rats (aged 4-5 weeks) were evenly divided into the control group and chronic unpredictable stress (CUS) group. Behavioral tests were performed, and then changes in myelinated fibers and myelin ultrastructure in hippocampal subfields in depression model rats were investigated using modern stereological methods and transmission electron microscopy techniques.

RESULTS

After a four-week CUS protocol, CUS rats showed depressive-like and anxiety-like behaviors. The total length and total volume of myelinated fibers were reduced in the CA1 region and DG in the CUS group compared with the control group. The total volumes of myelin sheaths and axons in the CA1 region but not in the DG were significantly lower in the CUS group than in the control group. The decrease in the total length of myelinated nerve fibers in the CA1 region in CUS rats was mainly due to a decrease in the length of myelinated fibers with a myelin sheath thickness of 0.15 μm-0.20 μm.

LIMITATIONS

The exact relationship between the degeneration of myelin sheaths and depression-like, anxiety-like behaviors needs to be further investigated.

CONCLUSIONS

CUS induces depression- and anxiety-like behaviors, and the demyelination in the CA1 region induced by 4 weeks of CUS might be an important structural basis for these behaviors.

The Relationship Between Age at Incarceration and Lifetime Suicide Attempt Among a Nationally Representative Sample of U.S. Adults

To examine the association between age at incarceration and lifetime suicide attempt (SA), and whether it differs by gender. Lifetime prevalence of SA was compared between respondents with no incarceration, juvenile, and adult incarceration who completed the 2012-2013 National Survey of Alcohol and Related Conditions-III (N = 36,107). We compared the odds of SA, adjusting for sociodemographic characteristics, psychiatric disorders, and childhood adverse experiences, and stratified the results by gender. Adjusted odds ratio (AOR) of SA relative to no incarceration history was 1.66 (95% Confidence Interval [CI] 1.32-2.07) for adult incarceration and 2.00 (95% CI 1.49-2.70) for juvenile incarceration. AOR of SA relative to no incarceration history was 2.14 (95% CI 1.56-2.93) for adult and 2.15 (95% CI 1.38-3.35) for juvenile incarceration in women; it was 1.73 (95% CI 1.14-2.60) in juvenile incarceration relative to no incarceration history in men. A history of incarceration may increase SA, particularly among juvenile and women offenders.

Perceived stress of adolescents during the COVID-19 lockdown: Bayesian multilevel modeling of the Czech HBSC lockdown survey

Objective

Long-term isolation, including lockdowns and quarantines, may have a distressing effect on anyone experiencing it. Adolescent brain architecture is very sensitive to environmental adversities, and the mental health development of adolescents may be particularly vulnerable during the pandemic era. In order to better understand the triggers for perceived adolescent stress (PSS) during the COVID-19 lockdown, the present study aimed to assess the effects of social well-being and changes in time use during the lockdown, as well as the family COVID experience of adolescents.

Methods

The sample for this study comprised n = 3,440 adolescents (54.2% girls; mean age = 13.5 ± 1.6 years). Bayesian correlations between PSS, health and well-being variables were assessed. PSS was then modeled as an outcome variable in a series of nested Bayesian multilevel regression models.

Results

The negative impact of the COVID-19 lockdown was more apparent in girls. PSS was moderately correlated with adolescent health and well-being. The strongest predictor of higher level of PSS was frequent feeling of loneliness. On the contrary, lower level of PSS was most associated with having someone to talk to.

Conclusion

Long-term social isolation of adolescents could be harmful to their mental health. Psychological coping strategies to prevent the consequences of social isolation and development of mental health problems should be promoted on the individual, family, and even community level.

Sex- and age-dependent effects of chronic corticosterone exposure on depressive-like, anxiety-like, and fear-related behavior: Role of amygdala glutamate receptors in the rat

Persistent glucocorticoid elevation consistent with chronic stress exposure can lead to psychopathology, including mood and anxiety disorders. Women and stress-exposed adolescents are more likely to be diagnosed with mood disorders, suggesting that sex and age are important factors in determining vulnerability, though much remains to be determined regarding the mechanisms underlying this risk. Thus, the aim of the present experiments was to use the chronic corticosterone (CORT) exposure paradigm, a model of depression-like behavior that has previously been established primarily in adult males, to determine the mood-related effects of CORT in female and adolescent rats. Depression- and anxiety-like effects in adulthood were determined using the sucrose preference (SPT), the forced swim test (FST), the elevated plus maze, and fear conditioning. Basolateral amygdala (BLA) and medial prefrontal cortex (mPFC) glutamate receptor subunit levels were then measured. In a subsequent experiment, adult male and female rats were tested for the effects of pharmacological activation (via AMPA) or inhibition (via NBQX) of AMPA receptors in the BLA on behavior in the FST. Overall, females showed reduced anxiety- and depressive-like behaviors relative to males. However, females treated with CORT in adolescence, but not adulthood, had increased immobility in the FST, indicative of depression-like behavior. In contrast, CORT did not alter behavior in adolescent-treated males, though the previously reported depression-like effect of adult CORT exposure was observed. Control females had higher expression of the AMPA receptor subunits GluA1 and GluA2/3 selectively in the BLA relative to males. Adolescent CORT treatment, however, decreased BLA GluA1 and GluA2/3 expression in females, but increased expression in males, consistent with the direction of depression-like behavioral effects. Male and female rats also demonstrated opposing patterns of response to BLA AMPA receptor modulation in the FST, with AMPA infusion magnifying the sex difference of decreased immobility in females. Overall, these experiments show that increased glutamate receptor function in the BLA may decrease the risk of developing depressive-like behavior, further supporting efforts to target glutamatergic receptors for the treatment of stress-related psychiatric disorders. These findings also support further focus on sex as a biological variable in neuropsychiatric research.

The Association Between Neighborhood Poverty and Hippocampal Volume Among Individuals at Clinical High-Risk for Psychosis: The Moderating Role of Social Engagement

Reductions in hippocampal volume (HV) have been associated with both prolonged exposure to stress and psychotic illness. This study sought to determine whether higher levels of neighborhood poverty would be associated with reduced HV among individuals at clinical high-risk for psychosis (CHR-P), and whether social engagement would moderate this association. This cross-sectional study included a sample of participants (N  =  174, age-range = 12-33 years, 35.1% female) recruited for the second phase of the North American Prodrome Longitudinal Study. Generalized linear mixed models tested the association between neighborhood poverty and bilateral HV, as well as the moderating role of social engagement on this association. Higher levels of neighborhood poverty were associated with reduced left (β  =  -0.180, P  =  .016) and right HV (β  =  -0.185, P  =  .016). Social engagement significantly moderated the relation between neighborhood poverty and bilateral HV. In participants with lower levels of social engagement (n  =  77), neighborhood poverty was associated with reduced left (β  =  -0.266, P  =  .006) and right HV (β = -0.316, P  = .002). Among participants with higher levels of social engagement (n = 97), neighborhood poverty was not significantly associated with left (β  =  -0.010, P  =  .932) or right HV (β  =  0.087, P  =  .473). In this study, social engagement moderated the inverse relation between neighborhood poverty and HV. These findings demonstrate the importance of including broader environmental influences and indices of social engagement when conceptualizing adversity and potential interventions for individuals at CHR-P.

A Longitudinal Process Model Evaluating the Effects of Cooperative Learning on Victimization, Stress, Mental Health, and Academic Engagement in Middle School

Mental health is a significant concern among young people, particularly during the COVID-19 pandemic. Notably, mental health problems can significantly reduce student performance in school, including both engagement and achievement. Both mental health problems and reduced student performance often arise due to peer victimization, which can include teasing, racial- or gender-based discrimination, and/or physical assault. Stress has been proposed as one mechanism through which victimization influences mental health, and stress can also interfere with academic performance at school, including engagement and achievement. To date, however, no research has evaluated longitudinal associations between victimization and stress, and how these longitudinal patterns may impact adolescent behavior and mental health. In this study, we used data from a 2-year cluster randomized trial of cooperative learning to evaluate an etiological process model that includes (1) longitudinal reciprocal effects between victimization and stress, and (2) the effects of both victimization and stress on student mental health and academic engagement. We hypothesized that victimization and stress would have significant reciprocal effects, and that both would predict greater mental health problems and lower academic engagement. We further hypothesized that cooperative learning would have significant effects on all constructs. We found partial support for this model, whereby stress predicted greater victimization, but victimization did not predict increased stress. While both factors were linked to student outcomes, stress was a more powerful predictor. We also found significant salutary effects of cooperative learning on all constructs. The implications of these results for student behavioral and mental health are discussed.

Altered Development of Prefrontal GABAergic Functions and Anxiety-like Behavior in Adolescent Offspring Induced by Prenatal Stress

Maternal stress can afflict fetal brain development, putting the offspring at risk of cognitive deficits, including anxiety. The prefrontal cortex (PFC), a protracted maturing region, is notably affected by prenatal stress (PS). However, it remains unclear how PS interferes with the maturation of the GABAergic system, considering its functional adjustment in the PFC during adolescence. The present study thus investigated the long-lasting consequences of PS on the prefrontal GABAergic functions of adolescent offspring. Pregnant Sprague–Dawley rats were divided into controls and the PS group, which underwent restraint stress during the last week of gestation. Male pups from postnatal days (PND) 40–42 were submitted to the elevated plus maze (EPM) test. Proteins essentially involved in GABAergic signaling were then examined in PFC tissues, including the K+-Cl− cotransporter (KCC2), Na+-K+-Cl− cotransporter (NKCC1), α1 and α5 subunits of GABA type A receptors (GABAA receptors), and parvalbumin (PV), along with cAMP response element-binding protein phosphorylation (pCREB), which reacts in the plasticity regulation of PV-positive interneurons. The results revealed that the higher anxiety-like behavior of PS adolescent rats concurred with the significant decreases of the KCC2 and α1 subunits, with PV- and pCREB-lowered levels. The findings suggested that PS disrupts the continuance of PFC maturity by reducing the essential elements of GABAergic functions. These changes likely underlie the anxiety emerging in adolescence, possibly progressing to mental disorders.

Early Marriage in Adolescence and Risk of High Blood Pressure and High Blood Glucose in Adulthood: Evidence from India

Adolescence, the transition phase to adulthood, is a critical period for physical and psychological development. Disruptions during this period, such as getting married, could result in various adverse short- and long-term health outcomes. This study aimed to assess the differential risk of two common chronic conditions—high blood pressure and high blood glucose—in adult women (20–49 years) who were married during different stages of adolescence (10–19 years) compared to women who were married in their youth (20–24 years). Using the most recent nationally representative data from India, we separately assessed the odds in favor of having the two chronic conditions for women who were married during early (10–14 years), middle (15–17 years), and late (18–19 years) adolescence. We found that an earlier age at marriage during adolescence was associated with a higher risk of chronic conditions later in life. Women who were married during early adolescence were respectively 1.29 and 1.23 times more likely (p < 0.001) to have high blood pressure and high blood glucose compared to women who were married in their youth. These findings highlight the importance of preventing underage marriage among adolescent females to address the risk of downstream chronic health consequences as adults.

Neurobiological Mechanisms Modulating Emotionality, Cognition and Reward-Related Behaviour in High-Fat Diet-Fed Rodents

Affective and substance-use disorders are associated with overweight and obesity-related complications, which are often due to the overconsumption of palatable food. Both high-fat diets (HFDs) and psychostimulant drugs modulate the neuro-circuitry regulating emotional processing and metabolic functions. However, it is not known how they interact at the behavioural level, and whether they lead to overlapping changes in neurobiological endpoints. In this literature review, we describe the impact of HFDs on emotionality, cognition, and reward-related behaviour in rodents. We also outline the effects of HFD on brain metabolism and plasticity involving mitochondria. Moreover, the possible overlap of the neurobiological mechanisms produced by HFDs and psychostimulants is discussed. Our in-depth analysis of published results revealed that HFDs have a clear impact on behaviour and underlying brain processes, which are largely dependent on the developmental period. However, apart from the studies investigating maternal exposure to HFDs, most of the published results involve only male rodents. Future research should also examine the biological impact of HFDs in female rodents. Further knowledge about the molecular mechanisms linking stress and obesity is a crucial requirement of translational research and using rodent models can significantly advance the important search for risk-related biomarkers and the development of clinical intervention strategies.

Inhibition of Hippocampal Neurogenesis Starting in Adolescence Increases Anxiodepressive Behaviors Amid Stress

Stressors during the adolescent period can affect development of the brain and have long-lasting impacts on behavior. Specifically, adolescent stress impairs hippocampal neurogenesis and can increase risk for anxiety, depression, and a dysregulated stress response in adulthood. In order to model the functional effects of reduced hippocampal neurogenesis during adolescence, a transgenic neurogenesis ablation rat model was used to suppress neurogenesis during the adolescent period and test anxiodepressive behaviors and stress physiology during adulthood. Wildtype and transgenic (TK) rats were given valganciclovir during the first two weeks of adolescence (4-6 weeks old) to knock down neurogenesis in TK rats. Starting in young adulthood (13 weeks old), blood was sampled for corticosterone at several time points following acute restraint stress to measure negative feedback of the stress response, and rats were tested on a battery of anxiodepressive tests at baseline and following acute restraint stress. Although TK rats had large reductions in both cell proliferation during adolescence, as measured by bromodeoxyuridine (BrdU), and ongoing neurogenesis in adulthood (by doublecortin), resulting in decreased volume of the dentate gyrus, negative feedback of the stress response following acute restraint was similar across all rats. Despite similar stress responses, TK rats showed higher anxiety-like behavior at baseline. In addition, only TK rats had increased depressive-like behavior when tested after acute stress. Together, these results suggest that long-term neurogenesis ablation starting in adolescence produces hippocampal atrophy and increases behavioral caution and despair amid stressful environments.