Childhood stressful events, HPA axis and anxiety disorders

Biopsychosocial factors in oral and systemic diseases: a scoping review

Background

The association between chronic oral diseases and other major systemic health conditions, commonly referred to as the oral-systemic health connection, has been previously studied with several underlying common risk factors and pathways linking both groups of diseases. Psychosocial factors contribute to an increased susceptibility to chronic oral and non-oral diseases. The aim of this review is to summarize the current state of knowledge on the role of psychosocial stress in chronic oral and systemic diseases.

Methods

A search strategy was built and a literature search was conducted using four databases (CINAHL, Embase, Medline, PsycINFO). A combination of search terms related to psychosocial stress, systemic disease, and oral conditions were used. Studies were eligible for inclusion if they included human adults (aged 18 years and older), included psychosocial factors as an exposure measure, and outcome measures of both an oral and systemic condition. Only English-language articles were considered. Pilot testing of the data extraction form and calibration were conducted and data were extracted independently by one researcher.

Results

A total of fifteen articles out of eighty full-text articles screened were determined to be eligible for inclusion in this review. Periodontal disease was the most commonly studied oral disease, measured in 53% of included articles, with the most commonly studied systemic diseases being of mental health conditions (40%) and diabetes (47%). Psychosocial stress was measured using a range of psychometric indicators and/or biomarkers, including perceived stress, individual behaviours, childhood adversity, and cortisol. In total, fourteen studies found a positive association between measures of psychosocial stress and oral-systemic health.

Conclusion

Psychosocial stress may be a common contributor to both chronic oral and non-oral diseases.

Exploring volumetric abnormalities in subcortical L-HPA axis structures in pediatric generalized anxiety disorder

BACKGROUND

Pediatric generalized anxiety disorder (GAD) is debilitating and increasingly prevalent, yet its etiology remains unclear. Some believe the disorder to be propagated by chronic dysregulation of the limbic-hypothalamic-pituitary-adrenal (L-HPA) axis, but morphometric studies of implicated subcortical areas have been largely inconclusive. Recognizing that certain subcortical subdivisions are more directly involved in L-HPA axis functioning, this study aims to detect specific abnormalities in these critical areas.

METHODS

Thirty-eight MRI scans of preschool children with (n = 15) and without (n = 23) GAD underwent segmentation and between-group volumetric comparisons of the basolateral amygdala (BLA), ventral hippocampal subiculum (vSC), and mediodorsal medial magnocellular (MDm) area of the thalamus.

RESULTS

Children with GAD displayed significantly larger vSC compared to healthy peers, F(1, 31) = 6.50, pFDR = .048. On average, children with GAD presented with larger BLA and MDm, Fs(1, 31) ≥ 4.86, psFDR ≤ .054. Exploratory analyses revealed right-hemispheric lateralization of all measures, most notably the MDm, F(1, 31) = 8.13, pFDR = .024, the size of which scaled with symptom severity, r = .83, pFDR = .033.

CONCLUSION

The BLA, vSC, and MDm are believed to be involved in the regulation of anxiety and stress, both individually and collectively through the excitation and inhibition of the L-HPA axis. All were found to be enlarged in children with GAD, perhaps reflecting hypertrophy related to hyperexcitability, or early neuronal overgrowth. Longitudinal studies should investigate the relationship between these early morphological differences and the long-term subcortical atrophy previously observed.

Childhood maltreatment, multilocus HPA-axis genetic variation and adolescent comorbidity profiles of depressive and anxiety symptoms

BACKGROUND

Despite a growing body of evidence showing both genetic and environmental influences on adolescent depression and anxiety, the involved comorbid mechanisms regarding gene-by-environment (G × E) interaction remain unclear.

OBJECTIVE

The current study was the first to investigate the extent to which multilocus hypothalamic-pituitary-adrenal (HPA)-axis genetic variants moderated the association between childhood maltreatment and adolescent comorbid depression and anxiety.

METHODS

The participants were 827 Chinese Han adolescents (Mage = 16.45 ± 1.37 years; 50.2 % girls). A theory-driven multilocus genetic profile score (MGPS) was computed by calculating alleles of core HPA-axis genes (CRHR1, NR3C1, NR3C2, and FKBP5) associated with heightened stress reactivity. Childhood maltreatment was retrospectively collected using Childhood Trauma Questionnaire. Comorbidity profiles of self-reported adolescent depressive and anxiety symptoms were constructed via person-centered latent profile analysis.

RESULTS

Three heterogeneous comorbidity profiles of depressive and anxiety symptoms were identified: comorbid severe symptoms (9.7 %), comorbid moderate symptoms (46.4 %) and comorbid mild symptoms (43.9 %). The HPA-axis related MGPS significantly interacted with childhood maltreatment, especially emotional maltreatment (emotional abuse: OR = 1.14, 95 % CI [1.03, 1.26], p < .01; emotional neglect: OR = 1.07, 95 % CI [1.01, 1.13], p < .05), to distinguish the comorbid severe symptoms profile from the comorbid mild symptoms profile (OR = 1.03, 95 % CI [1.01, 1.06], p < .05).

CONCLUSION

The HPA-axis related genes showed an additive polygenic sensitivity toward childhood maltreatment, which might be one of the polygenic G × E mechanisms underlying adolescent comorbid depression and anxiety.

Review of the direct and indirect effects of hyperglycemia on the HPA axis in T2DM and the co-occurrence of depression

Type 2 diabetes mellitus (T2DM) is characterized by persistent hyperglycemia which is further associated with hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. Several studies have shown that HPA axis hyperactivity is heightened in the chronic hyperglycemic state with severe hyperglycemic events more likely to result in a depressive disorder. The HPA axis is also regulated by the immune system. Upon stress, under homeostatic conditions, the immune system is activated via the sympatho-adrenal-medullary axis resulting in an immune response which secretes proinflammatory cytokines. These cytokines aid in the activation of the HPA axis during stress. However, in T2DM, where there is persistent hyperglycemia, the immune system is dysregulated resulting in the elevated concentrations of these cytokines. The HPA axis, already activated by the hyperglycemia, is further activated by the cytokines which all contribute to a diagnosis of depression in patients with T2DM. However, the onset of T2DM is often preceded by pre-diabetes, a reversible state of moderate hyperglycemia and insulin resistance. Complications often seen in T2DM have been reported to begin in the pre-diabetic state. While the current management strategies have been shown to ameliorate the moderate hyperglycemic state and decrease the risk of developing T2DM, research is necessary for clinical studies to profile these direct effects of moderate hyperglycemia in pre-diabetes on the HPA axis and the indirect effects moderate hyperglycemia may have on the HPA axis by investigating the components of the immune system that play a role in regulating this pathway.

A paradoxical switch: the implications of excitatory GABAergic signaling in neurological disorders

Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. In the mature brain, inhibitory GABAergic signaling is critical in maintaining neuronal homeostasis and vital human behaviors such as cognition, emotion, and motivation. While classically known to inhibit neuronal function under physiological conditions, previous research indicates a paradoxical switch from inhibitory to excitatory GABAergic signaling that is implicated in several neurological disorders. Various mechanisms have been proposed to contribute to the excitatory switch such as chloride ion dyshomeostasis, alterations in inhibitory receptor expression, and modifications in GABAergic synaptic plasticity. Of note, the hypothesized mechanisms underlying excitatory GABAergic signaling are highlighted in a number of neurodevelopmental, substance use, stress, and neurodegenerative disorders. Herein, we present an updated review discussing the presence of excitatory GABAergic signaling in various neurological disorders, and their potential contributions towards disease pathology.

Disruption of Cdk5-GluN2B complex by a small interfering peptide attenuates social isolation-induced escalated intermale attack behavior and hippocampal oxidative stress in mice

Social isolation has emerged as a significant issue during the COVID-19 pandemic that can adversely impact human mental health and potentially lead to pathological aggression. Given the lack of effective therapeutic interventions for aggressive behavior, alternative approaches are necessary. In this study, we utilized a genetic method combined with a pharmacological approach to identify and demonstrate the crucial role of Cdk5 in escalated intermale attack behavior induced by 2-week social isolation. Moreover, we developed a small peptide that effectively disrupts the interaction between Cdk5 and GluN2B, given the known involvement of this complex in various neuropsychiatric disorders. Administration of the peptide, either systemically or via intrahippocampal injection, significantly reduced oxidative stress in the hippocampus and attenuated intermale attack behavior induced by 2-week social isolation. These findings highlight the previously unknown role of the hippocampal Cdk5-GluN2B complex in social isolation-induced aggressive behavior in mice and propose the peptide as a promising therapeutic strategy for regulating attack behavior and oxidative stress.

Sex-dependent association of DNA methylation of HPA axis-related gene FKBP5 with obsessive-compulsive disorder

AIMS

Although hypothalamic-pituitary-adrenal (HPA) axis dysregulation in obsessive-compulsive disorder (OCD) has been reported, epigenetic changes in HPA axis-related genes have not been well studied in OCD. The present study investigated whether the epigenetic regulation of FK506-binding protein 51 gene (FKBP5) intron 7 is associated with OCD status in each sex. In addition, relationships among the DNA methylation levels of FKBP5 intron 7, OCD status and early-life trauma were explored.

METHODS

A total of 267 patients with OCD and 201 controls aged between 18 and 40 years were recruited. Demographic and clinical assessment, FKBP5 rs1360780 genotyping, and pyrosequencing of FKBP5 intron 7 were conducted. DNA was extracted from peripheral blood leucocytes. First, multivariate analysis of covariance for differential DNA methylation levels between OCD patients and controls was conducted with adjustment for FKBP5 rs1360780 genotype, early-life trauma, depressive symptoms, and age as covariates in each sex. Next, path analysis was conducted to determine the mediation effects of DNA methylation levels of FKBP5 between early-life trauma and OCD status. In addition, sensitivity analyses for medication and lifetime major depression were also performed.

RESULTS

DNA methylation at the FKBP5 intron 7 CpG site was significantly lower in men with OCD, compared to controls (mean difference -1.33%, 95% CI -2.11 to -0.55, p < 0.001). The results remained significant for drug naïve or free subjects (mean difference -1.27%, 95% CI -2.18 to -0.37, p = 0.006, in men) and for subjects without lifetime major depressive disorder (mean difference -1.60%, 95% CI -2.54 to -0.66, p < 0.001, in men). The mediation effect of DNA methylation levels was not significant between early-life trauma and OCD status.

CONCLUSION

These findings suggest that epigenetic factors of HPA axis-related gene FKBP5 may play a role in the pathogenesis of OCD. Further studies are needed to determine how altered DNA methylation of FKBP5 intron 7 and HPA axis function are involved in OCD.

Internalizing disorders as a mediator of the association between adverse childhood experiences and perceived medication intolerance or poly-allergy

OBJECTIVES

There is a well-established link between adverse childhood events, mental health, and physical health conditions. There is also a large literature showing the relationship between medication intolerance or allergies, and poor health outcomes. However, less is understood about the role of medication intolerance and adverse childhood events. Thus, the present study examines the relationship between adverse childhood events, internalizing disorders (depression, anxiety) and medication intolerance.

METHOD

Three hundred forty-nine participants were recruited from 11 primary care practices and health networks located in a large, Midwestern metropolitan area. Unrelated linear and Poisson regression was used to determine whether internalizing disorders, such as depression and anxiety, mediated the relationship between adverse childhood experiences (ACEs) and allergies to medications, accounting for error terms in regression equations that were correlated.

RESULTS

Results indicated an association between ACEs and number of allergies to medication, whereby ACEs was associated with depression, anxiety and number of allergies. Sensitivity analysis confirmed these findings. There was a small but significant indirect effect of anxiety on allergies to medication after bootstrapping.

CONCLUSION

This study found that inflammatory responses occurring because of trauma and depression may be increasing medication allergies. However, given the size of the sample, more research is needed to confirm these results. Implications for healthcare providers are discussed.

Node of Ranvier remodeling in chronic psychosocial stress and anxiety

Differential expression of myelin-related genes and changes in myelin thickness have been demonstrated in mice after chronic psychosocial stress, a risk factor for anxiety disorders. To determine whether and how stress affects structural remodeling of nodes of Ranvier, another form of myelin plasticity, we developed a 3D reconstruction analysis of node morphology in C57BL/6NCrl and DBA/2NCrl mice. We identified strain-dependent effects of chronic social defeat stress on node morphology in the medial prefrontal cortex (mPFC) gray matter, including shortening of paranodes in C57BL/6NCrl stress-resilient and shortening of node gaps in DBA/2NCrl stress-susceptible mice compared to controls. Neuronal activity has been associated with changes in myelin thickness. To investigate whether neuronal activation is a mechanism influencing also node of Ranvier morphology, we used DREADDs to repeatedly activate the ventral hippocampus-to-mPFC pathway. We found reduced anxiety-like behavior and shortened paranodes specifically in stimulated, but not in the nearby non-stimulated axons. Altogether, our data demonstrate (1) nodal remodeling of the mPFC gray matter axons after chronic stress and (2) axon-specific regulation of paranodes in response to repeated neuronal activity in an anxiety-associated pathway. Nodal remodeling may thus contribute to aberrant circuit function associated with anxiety disorders.

Educational attainment and anxiety in middle-aged and older Europeans

We examined the relationship between educational attainment (EA) and anxiety symptoms in a sample of 77,792 individuals (median age = 64 years, 55% female) from the Survey of Health, Ageing and Retirement in Europe. Using logistic regression, we estimated odds ratio (OR) with 95% confidence interval (CI) for the association between EA (7 educational levels based on International Standard Classification of Education) and anxiety symptoms (12 or more points from the shortened 5-item version of the Beck Anxiety Inventory), adjusting for sociodemographic and health-related factors. We further explored whether the relationship varied by region, sex and age group. Independent of sociodemographic and health-related factors, higher levels of EA were associated with lower odds of anxiety symptoms. The magnitude of this association plateaued at first stage of tertiary education (OR 0.40; 95% CI 0.35-0.47, p < 0.001). The association was stronger in females, middle-aged individuals and in Central and Eastern Europe while not apparent in Northern Europe. Our findings suggest that individuals with higher education might be protected against anxiety throughout life. The protective effect of education against anxiety symptoms is more pronounced in less egalitarian regions and in females.

Probiotics, Live Biotherapeutic Products (LBPs), and Gut-Brain Axis Related Psychological Conditions: Implications for Research and Dietetics

It is well-known that probiotics have key roles in the crosstalk between the gut and brain in terms of nutrition and health. However, when investigating their role in nutrition and health, it can be important to discriminate probiotics used as foods, food supplements, or drugs. For clarification of this terminology, the Food and Drug Administration (FDA) has established a new "live biotherapeutic products" (LBP) category, expressing pharmaceutical expectations and to reduce confusion in the literature. Growing evidence advises that the community of microorganisms found in the gut microbiota is associated with psychological conditions. Hence, it is thought that LBPs may positively affect depression, anxiety, bipolar disorder, and schizophrenia by reducing inflammation, improving gut microbiota, and balancing gut neurometabolites. This review focuses on the specific position of probiotics as LBPs in psychological conditions. Condition-specific potential pathways and mechanisms of LBPs and the prominent strains are discussed in the light of novel studies for future research, dietetic and pharmaceutical applications.

Anxiolytic effects of Chrysanthemum morifolium Ramat Carbonisata-based carbon dots in mCPP-induced anxiety-like behavior in mice: a nature-inspired approach

Introduction: Anxiety disorders have emerged as a predominant health concern, yet existing pharmacological treatments for anxiety still present various challenges. Chrysanthemum morifolium Ramat Carbonisata (CMRC) has been utilized in China for approximately 400 years as a therapeutic intervention for anxiety disorders. In this study, a novel type of carbon dots derived from the decoction of Chrysanthemum morifolium Ramat Carbonisata (CMRC-CDs) was identified and isolated, and their morphological structure and functional groups were characterized. Furthermore, the effects of CMRC-CDs on m-chlorophenylpiperazine (mCPP)-induced anxiety-like behaviour in mice were examined and quantified. In order to investigate the potential mechanisms of their anxiolytic effects, concentrations of hypothalamic-pituitary-adrenal (HPA) axis hormones, amino acid neurotransmitters, and monoamine neurotransmitters were measured. Methods: In this study, we synthesized CMRC-CDs and evaluated their potential anti-anxiety effects in a controlled experiment involving 48 male ICR mice. The mice were randomly divided into six groups, treated with CMRC-CDs at different doses for 14 days, and subjected to Open-Field (OF) and Elevated Plus Maze (EPM) tests. Post-behavioral evaluations, blood samples and brain tissues were collected for neurotransmitter and Hypothalamic-Pituitary-Adrenal (HPA) axis hormone quantification via ELISA. Additionally, cytotoxicity of CMRC-CDs was assessed using a Cell Counting Kit-8 (CCK-8) assay on RAW 264.7 cells. Results and Discussion: CMRC-CDs were spherical and homogeneously dispersed, with diameters ranging from 1.4 to 4.0 nm and an abundance of chemical groups on their surface. In the open-field (OF) test, mice pre-treated with CMRC-CDs demonstrated an increased proportion of time spent in the central area and a higher frequency of entries into the central area. In the elevated plus maze (EPM) test, mice pre-treated with CMRC-CDs exhibited a greater number of entries into the open arm and an extended duration spent in the open arm. CMRC-CDs were observed to decrease serum concentrations of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and corticosterone (CORT). Furthermore, CMRC-CDs were found to increase γ-aminobutyric acid (GABA) and 5-hydroxytryptamine (5-HT) levels, while concurrently reducing glutamic acid (Glu) concentrations in brain tissue. CMRC-CDs demonstrated anxiolytic effects, which may be attributed to their modulation of hormones and neurotransmitters. This finding suggests the potential therapeutic value of CMRC-CDs in the clinical treatment of anxiety disorders.

The brain-gut-microbiota axis in the treatment of neurologic and psychiatric disorders

The human gut microbiota is a complex ecosystem made of trillions of microorganisms. The composition can be affected by diet, metabolism, age, geography, stress, seasons, temperature, sleep, and medications. The increasing evidence about the existence of a close and bi-directional correlation between the gut microbiota and the brain indicates that intestinal imbalance may play a vital role in the development, function, and disorders of the central nervous system. The mechanisms of interaction between the gut-microbiota on neuronal activity are widely discussed. Several potential pathways are involved with the brain-gut-microbiota axis, including the vagus nerve, endocrine, immune, and biochemical pathways. Gut dysbiosis has been linked to neurological disorders in different ways that involve activation of the hypothalamic-pituitary-adrenal axis, imbalance in neurotransmitter release, systemic inflammation, and increase in the permeability of the intestinal and the blood-brain barrier. Mental and neurological diseases have become more prevalent during the coronavirus disease 2019pandemic and are an essential issue in public health globally. Understanding the importance of diagnosing, preventing, and treating dysbiosis is critical because gut microbial imbalance is a significant risk factor for these disorders. This review summarizes evidence demonstrating the influence of gut dysbiosis on mental and neurological disorders.

Early Life Stress in Mice Leads to Impaired Colonic Corticosterone Production and Prolonged Inflammation Following Induction of Colitis

BACKGROUND

Early life stress (ELS) is an environmental trigger believed to promote increased risk of IBD. Our goal was to identify mechanisms whereby ELS in mice affects susceptibility to and/or severity of gut inflammation.

METHODS

We utilized 2 published animal models of ELS. In the first model, newborn mice were separated from the dam daily for 4 to 8 hours starting on postnatal day 2 and then weaned early on postnatal day 17. Control mice were left undisturbed with the dams until weaning on postnatal day 21. In the second model, dams were fed dexamethasone or vehicle ad libitum in drinking water on postpartum days 1 to 14. Plasma and colonic corticosterone were measured in juvenile and adult mice. Colitis was induced in 4-week-old mice via intraperitoneal injection of interleukin (IL)-10 receptor blocking antibody every 5 days for 15 days. Five or 15 days later, colitis scores and transcripts for Tnf, glucocorticoid receptors, and steroidogenic enzymes were measured.

RESULTS

Mice exposed to ELS displayed reduced plasma and colonic corticosterone. Control animals showed improvements in indices of inflammation following cessation of interleukin-10 receptor blockade, whereas ELS-exposed animals maintained high levels of Tnf and histological signs of colitis. In colitic animals, prior exposure to ELS was associated with significantly lower expression of genes associated with corticosterone synthesis and responsiveness. Finally, TNF stimulation of colonic crypt cells from ELS mice led to increased inhibition of corticosterone synthesis.

CONCLUSIONS

Our study identifies impaired local glucocorticoid production and responsiveness as a potential mechanism whereby ELS predisposes to chronic colitis in susceptible hosts.

A bidirectional relationship between diabetes mellitus and anxiety: A systematic review and meta-analysis

BACKGROUND

Due to the existence of inconsistencies in the evidence regarding the direction and extent of association between diabetes and anxiety disorders, the anxiety-diabetes comorbidity remains an issue of debate.

AIM

To estimate the proportion and risk of diabetes among individuals with anxiety disorder and vice versa.

METHODS

A systematic review was conducted using studies retrieved from databases and grey literature, with the last database search being conducted on April 15, 2021. The methodological rigor of studies was assessed using the National Institute of Health quality assessment tool. Prevalence and effect size (ES) estimates were pooled using a random effect model. Heterogeneity was assessed using the Higgins' I² statistical test, and subgroup analysis conducted.

RESULTS

We included 68 studies presenting data from 2,128,029 participants. The prevalence of anxiety disorders in diabetic patients was 28% (95% CI: 26%, 31%); however, subgroup analysis showed significant differences based on type of anxiety assessment scales, study location, and type of diabetes. The prevalence of diabetes among patients with anxiety disorders was 12% (95% CI: 9%, 16%). Patients with anxiety disorders were found to have a 19% higher risk of diabetes (pooled effect size (ES) = 1.19, 95% CI: 1.13, 1.26). Diabetic patients were found to have a 41% higher risk of developing anxiety disorders (ES = 1.41, 95% CI: 1.19, 1.62).

CONCLUSIONS

There is a higher risk of anxiety disorders in patients with diabetes mellitus and vice versa. It is recommended to screen diabetic patients for anxiety at initial diagnosis and follow-up visits. Similarly, patients with anxiety disorders should have regular screening for diabetes.

REVIEW REGISTRATION

PROSPERO registration number CRD42021252475.

Psychological trauma as a transdiagnostic risk factor for mental disorder: an umbrella meta-analysis

This umbrella review is the first to systematically examine psychological trauma as a transdiagnostic risk factor across psychiatric conditions. We searched Pubmed, Scopus, and PsycNET databases from inception until 01/05/2021 for systematic reviews/meta-analyses evaluating the association between psychological trauma and at least one diagnosed mental disorder. We re-calculated the odds ratio (OR), then classified the association as convincing, highly suggestive, suggestive, or weak, based on the number of cases and controls with and without psychological trauma, random-effects p value, the 95% confidence interval of the largest study, heterogeneity between studies, 95% prediction interval, small-study effect, and excess significance bias. Additional outcomes were the association between specific trauma types and specific mental disorders, and a sensitivity analysis for childhood trauma. Transdiagnosticity was assessed using TRANSD criteria. The review was pre-registered in Prospero CRD42020157308 and followed PRISMA/MOOSE guidelines. Fourteen reviews met inclusion criteria, comprising 16,277 cases and 77,586 controls. Psychological trauma met TRANSD criteria as a transdiagnostic factor across different diagnostic criteria and spectra. There was highly suggestive evidence of an association between psychological trauma at any time-point and any mental disorder (OR = 2.92) and between childhood trauma and any mental disorder (OR = 2.90). Regarding specific trauma types, convincing evidence linked physical abuse (OR = 2.36) and highly suggestive evidence linked sexual abuse (OR = 3.47) with a range of mental disorders, and convincing evidence linked emotional abuse to anxiety disorders (OR = 3.05); there were no data for emotional abuse with other disorders. These findings highlight the importance of preventing early traumatic events and providing trauma-informed care in early intervention and psychiatric services.

Role of sirtuin1 in impairments of emotion-related behaviors in mice with chronic mild unpredictable stress during adolescence

Long-term exposure to physical and/or psychosocial stress during early life and/or adolescence increases the risk of psychiatric disorders such as major depressive disorder and anxiety disorders. However, the molecular mechanisms underlying early stress-induced brain dysfunction are poorly understood. In the present study, mice at 4 weeks old were subjected to chronic mild unpredictable stress (CMUS) for 4 weeks, and subsequently to assays of emotion-related behaviors. Thereafter, they were sacrificed and their brains were collected for real-time quantitative polymerase chain reaction (RT-qPCR). Mice with CMUS during adolescence showed despair behavior, anxiety-like behavior, social behavior deficits, and anhedonia in forced-swim, marble-burying, social interaction, and sucrose preference tests, respectively. Additionally, RT-qPCR revealed that the expression levels of sirtuin1 (SIRT1), a NAD⁺-dependent deacetylase that mediates stress responses, were down-regulated in the prefrontal cortex and hippocampus of mice with CMUS compared with control mice. Next, to investigate the pathophysiological role of decreased Sirt1 expression levels in stress-induced behavioral deficits, we assessed the effects of resveratrol, a pharmacological activator of SIRT1, in mice exposed to CMUS. Chronic treatment with resveratrol prevented -induced social behavior deficits and depression-like behaviors. These results suggest that CMUS during adolescence decreases Sirt1 expression in the brain, leading to deficits in emotional behavior. Accordingly, SIRT1 activators, such as resveratrol, may be preventive agents against abnormalities in emotional behavior following stress during an immature period.

Obsessive-compulsive disorder, insulin signaling and diabetes - A novel form of physical health comorbidity: The sweet compulsive brain

BACKGROUND

While a growing body of research highlights a bi-directional link between diabetes and mood disorders, little is known about the relationship between diabetes and obsessive-compulsive disorder (OCD). The aim of the present review is to investigate current evidence linking OCD, insulin-signaling and diabetes.

METHODS

A PubMed search was conducted to review all the available studies assessing diabetes, glucose metabolism and insulin-signaling in OCD patients and vice versa.

RESULTS

Some clinical and epidemiological studies show a higher prevalence of diabetes in OCD and vice versa compared to the general population. Animal and genetic studies suggest a possible role of insulin-signaling in the pathophysiology of OCD. Deep brain stimulation (DBS) studies suggest that abnormal dopaminergic transmission in the striatum may contribute to impaired insulin sensitivity in OCD. While DBS seems to increase insulin sensitivity, a possible protective role of serotonin reuptake-inhibitors on diabetic risk needs further studies.

CONCLUSION

Despite their preliminary nature, these data highlight the importance of further investigations aimed at assessing metabolic features in OCD patients and OCD symptoms in diabetes patients to understand the impact of each condition on the pathophysiology and course of the other. Understanding the role of insulin in the obsessive-compulsive brain could open new treatment pathways for OCD.

Larval Zebrafish as a Model for Mechanistic Discovery in Mental Health

Animal models are essential for the discovery of mechanisms and treatments for neuropsychiatric disorders. However, complex mental health disorders such as depression and anxiety are difficult to fully recapitulate in these models. Borrowing from the field of psychiatric genetics, we reiterate the framework of 'endophenotypes' - biological or behavioral markers with cellular, molecular or genetic underpinnings - to reduce complex disorders into measurable behaviors that can be compared across organisms. Zebrafish are popular disease models due to the conserved genetic, physiological and anatomical pathways between zebrafish and humans. Adult zebrafish, which display more sophisticated behaviors and cognition, have long been used to model psychiatric disorders. However, larvae (up to 1 month old) are more numerous and also optically transparent, and hence are particularly suited for high-throughput screening and brain-wide neural circuit imaging. A number of behavioral assays have been developed to quantify neuropsychiatric phenomena in larval zebrafish. Here, we will review these assays and the current knowledge regarding the underlying mechanisms of their behavioral readouts. We will also discuss the existing evidence linking larval zebrafish behavior to specific human behavioral traits and how the endophenotype framework can be applied. Importantly, many of the endophenotypes we review do not solely define a diseased state but could manifest as a spectrum across the general population. As such, we make the case for larval zebrafish as a promising model for extending our understanding of population mental health, and for identifying novel therapeutics and interventions with broad impact.

Neurobiology of Depression: Chronic Stress Alters the Glutamatergic System in the Brain-Focusing on AMPA Receptor

Major depressive disorder (MDD) is a common neuropsychiatric disorder affecting the mood and mental well-being. Its pathophysiology remains elusive due to the complexity and heterogeneity of this disorder that affects millions of individuals worldwide. Chronic stress is frequently cited as the one of the risk factors for MDD. To date, the conventional monoaminergic theory (serotonin, norepinephrine, and/or dopamine dysregulation) has received the most attention in the treatment of MDD, and all available classes of antidepressants target these monoaminergic systems. However, the contributions of other neurotransmitter systems in MDD have been widely reported. Emerging preclinical and clinical findings reveal that maladaptive glutamatergic neurotransmission might underlie the pathophysiology of MDD, thus revealing its critical role in the neurobiology of MDD and as the therapeutic target. Aiming beyond the monoaminergic hypothesis, studies of the neurobiological mechanisms underlying the stress-induced impairment of AMPA (a-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid)-glutamatergic neurotransmission in the brain could provide novel insights for the development of a new generation of antidepressants without the detrimental side effects. Here, the authors reviewed the recent literature focusing on the role of AMPA-glutamatergic neurotransmission in stress-induced maladaptive responses in emotional and mood-associated brain regions, including the hippocampus, amygdala, prefrontal cortex, nucleus accumbens and periaqueductal gray.

Hypothalamic-pituitary-adrenal Axis Multilocus Genetic Variation, Childhood Parenting and Adolescent Anxiety Symptoms: Evidence of Cumulative Polygenic Plasticity

Research suggests that genetic variants that regulate the hypothalamic-pituitary-adrenal (HPA) axis function moderate the association between parenting and anxiety symptoms, but these studies have primarily focused on (i) individual genes with very small and unreliable effect and (ii) the role of mothers as opposed to fathers. Using a multilocus genetic profile score approach, the current study is the first to examine the moderation effect of HPA-axis multilocus genetic variants on the associations of both maternal and paternal parenting with adolescent anxiety symptoms. In a sample of Chinese Han adolescents (N = 772; 50.1% girls; M_age = 16.48 ± 1.40 years, range: 15-20 years), a theory-driven multilocus genetic profile score was computed by counting the numbers of alleles that were previously linked to heightened stress reactivity in six HPA-axis related genes. This HPA-axis related multilocus genetic profile score equivalently interacted with both maternal and paternal parenting in the prediction of adolescent anxiety symptoms. Consistent with cumulative polygenic plasticity hypothesis of differential susceptibility model, adolescents with more versus low alleles linked to heightened stress reactivity not only suffered more from poor maternal or paternal parenting quality, but also benefited more from high maternal or paternal parenting quality. However, none of the individual HPA-axis genes within this multilocus genetic profile score yielded a significant gene-by-environment (G × E) interaction when examined in isolation. The findings survived after internal replication analysis and a novel, valid influence statistic DFBETAS analysis, demonstrating the robustness of the results. The current study highlights the potential value of using a multilocus approach to understand G × E effects underlying anxiety symptoms and emphasizes the role of both mothers and fathers in such gene-parenting interactions, especially in Chinese families.

Prenatal tobacco and alcohol exposures and the risk of anxiety symptoms in young adulthood: A population-based cohort study

BACKGROUND

Epidemiological studies have linked prenatal tobacco and alcohol exposures to internalizing behaviours in children and adolescents with inconsistent findings. Dearth of epidemiological studies have investigated the associations with the risk of experiencing symptoms of anxiety in young adulthood.

METHODS

Study participants (N = 1190) were from the Raine Study, a population-based prospective birth cohort based in Perth, Western Australia. Data on prenatal tobacco and alcohol exposures were available for the first and third trimesters of pregnancy. Experiencing symptoms of anxiety in young adulthood at age 20 years was measured by a short form of the Depression Anxiety Stress Scale (DASS 21). Relative risk (RR) of experiencing symptoms of anxiety in young adulthood for prenatal tobacco and alcohol exposures were estimated with log binomial regression.

RESULTS

After adjusting for potential confounders, we observed increased risks of experiencing symptoms of anxiety in young adults exposed to prenatal tobacco in the first trimester [RR = 1.52, 95% CI: 1.12-2.06, p-value < 0.01] and third trimester [RR = 1.53, 95% CI: 1.10-2.13, p-value  = 0.02]. However, we found insufficient statistical evidence for an association between first trimester [RR = 1.01, 95% CI: 0.76-1.22, p-value = 0.90] and third trimester [RR = 1.03, 95% CI: 0.80-1.34, p-value = 0.91] prenatal exposure to alcohol and the risk of experiencing symptoms of anxiety in young adults. There was a dose response association between prenatal tobacco exposure and increasing anxiety symptoms in offspring.

CONCLUSION

The findings of this study suggest that an association between prenatal tobacco exposure and risk of anxiety symptoms remains apparent into young adulthood.

Regulation of oxytocin receptor gene expression in obsessive-compulsive disorder: a possible role for the microbiota-host epigenetic axis

BACKGROUND

Obsessive-compulsive disorder (OCD) is a prevalent and severe clinical condition. Robust evidence suggests a gene-environment interplay in its etiopathogenesis, yet the underlying molecular clues remain only partially understood. In order to further deepen our understanding of OCD, it is essential to ascertain how genes interact with environmental risk factors, a cross-talk that is thought to be mediated by epigenetic mechanisms. The human microbiota may be a key player, because bacterial metabolites can act as epigenetic modulators. We analyzed, in the blood and saliva of OCD subjects and healthy controls, the transcriptional regulation of the oxytocin receptor gene and, in saliva, also the different levels of major phyla. We also investigated the same molecular mechanisms in specific brain regions of socially isolated rats showing stereotyped behaviors reminiscent of OCD as well as short chain fatty acid levels in the feces of rats.

RESULTS

Higher levels of oxytocin receptor gene DNA methylation, inversely correlated with gene expression, were observed in the blood as well as saliva of OCD subjects when compared to controls. Moreover, Actinobacteria also resulted higher in OCD and directly correlated with oxytocin receptor gene epigenetic alterations. The same pattern of changes was present in the prefrontal cortex of socially-isolated rats, where also altered levels of fecal butyrate were observed at the beginning of the isolation procedure.

CONCLUSIONS

This is the first demonstration of an interplay between microbiota modulation and epigenetic regulation of gene expression in OCD, opening new avenues for the understanding of disease trajectories and for the development of new therapeutic strategies.

Antibiotics, gut microbiota, and irritable bowel syndrome: What are the relations?

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder in which recurrent abdominal pain is associated with defecation or a change in bowel habits (constipation, diarrhea, or both), and it is often accompanied by symptoms of abdominal bloating and distension. IBS is an important health care issue because it negatively affects the quality of life of patients and places a considerable financial burden on health care systems. Despite extensive research, the etiology and underlying pathophysiology of IBS remain incompletely understood. Proposed mechanisms involved in its pathogenesis include increased intestinal permeability, changes in the immune system, visceral hypersensitivity, impaired gut motility, and emotional disorders. Recently, accumulating evidence has highlighted the important role of the gut microbiota in the development of IBS. Microbial dysbiosis within the gut is thought to contribute to all aspects of its multifactorial pathogenesis. The last few decades have also seen an increasing interest in the impact of antibiotics on the gut microbiota. Moreover, antibiotics have been suggested to play a role in the development of IBS. Extensive research has established that antibacterial therapy induces remarkable shifts in the bacterial community composition that are quite similar to those observed in IBS. This suggestion is further supported by data from cohort and case-control studies, indicating that antibiotic treatment is associated with an increased risk of IBS. This paper summarizes the main findings on this issue and contributes to a deeper understanding of the link between antibiotic use and the development of IBS.

A Scoping Review of Climate Change, Climate-Related Disasters, and Mental Disorders among Children in Low- and Middle-Income Countries

Children, particularly those living in low- and middle-income countries (LMICs), are highly vulnerable to climate change and its impacts. Our main objective was to conduct a scoping literature review to determine how exposure to climate change and climate-related disasters influences the presence of mental disorders among children in LMICs. We also aimed to identify gaps in this area of scholarship. We included studies of children in LMICs that had a climate change or climate-related disaster exposure and mental disorder outcome. Twenty-three studies were included in the final synthesis. Fourteen studies were conducted in China, three in India, two each in Pakistan and the Philippines, and one each in Namibia and Dominica. All studies assessed the association between a climate-related disaster exposure and a mental disorder outcome, while none explored broader climate change-related exposures. Post-traumatic stress disorder (n = 21 studies) and depression (n = 8 studies) were the most common mental disorder outcomes. There was considerable between-study heterogeneity in terms of sample size, follow-up length, and outcome measurement. Overall, the literature in this area was sparse. Additional high-quality research is required to better understand the impacts of climate-related disasters and climate change on mental disorders within this population to ultimately inform future policies and interventions.

Pediatric Cancer Survivorship: Impact Upon Hair Cortisol Concentration and Family Functioning

A clearer understanding of the association between a biomarker of long-term stress reactivity and family functioning among pediatric cancer survivors may guide both survivorship research and clinical practice. The current study examined the relationship between a long-term measure of hypothalamic-pituitary-adrenal (HPA) activity (cortisol concentration; CORT_HAIR) and parent-reported family functioning (Family Environment Scale; FES) in a cross-sectional sample of survivors (n = 26) and controls (n = 53). Child CORT_HAIR was not different in survivors and controls, though treatment severity was significantly related to child survivor CORT_HAIR. Child CORT_HAIR and parent CORT_HAIR were positively correlated. Cancer survivor parents reported greater FES Organization. Child CORT_HAIR was inversely associated with FES Independence, while parent CORT_HAIR was inversely correlated with FES Organization. Parent CORT_HAIR and FES Independence were significant and unique predictors of child CORT_HAIR. Our results provide preliminary evidence for a relationship between a stress biomarker, child CORT_HAIR, and family functioning among pediatric cancer survivors and controls.

Association between physical hazardous agent exposure and mental health in the Korean working population: the 5th Korean Working Conditions Survey

Background

Mental health problems are emerging issues in occupational safety and health, whereas the findings on the relationship between physical hazards and mental health are not consistent. The aim of our study was to investigate the association between physical hazard exposure and mental health outcomes including depression and anxiety.

Methods

We included 48,476 participants from the fifth Korean Working Conditions Survey (KWCS) in this study. The χ² test and logistic regression analyses were conducted to assess the association between physical hazard exposures and mental health. All statistical analyses were performed sex-specifically.

Results

In logistic regression analysis, the odds ratios (ORs) of depression were significantly increased in male workers who were exposed to vibration (severe OR: 1.54, 95% confidence interval [CI]: 1.21–1.95) and noise (severe OR: 1.93, 95% CI: 1.49–2.48) whereas the ORs of depression were not significant in female workers from vibration (severe OR: 0.86, 95% CI: 0.50–1.38) or noise exposure (severe OR: 1.39, 95% CI: 0.84–2.17). The ORs of anxiety were significantly increased in male workers with vibration (severe OR: 1.76, 95% CI: 1.43–2.15) and noise exposure (severe OR: 2.12, 95% CI: 1.69–2.63) whereas the OR between vibration and anxiety (severe OR: 1.45, 95% CI: 0.91–2.21) was not significant in female workers. High or low temperature exposure had significant associations with depression and anxiety in both male and female subjects.

Conclusions

Results of our study suggest that physical hazard exposures may be associated with increased risk of mental health problems including depression and anxiety. These associations are more prominent in male workers in comparison with female workers.

Stress System Activation in Children and Adolescents With Autism Spectrum Disorder

The mission of the human stress system is the maintenance of homeostasis in the presence of real or perceived, acute or chronic stressors. The hypothalamic–pituitary–adrenal (HPA) axis and the autonomic nervous system (ANS) are the stress system-related neuroendocrine pathways. There is abundant evidence that children and adolescents with autism spectrum disorder (ASD) may exhibit atypical function within the HPA axis and the ANS both at the resting state and during the presence of social and/or non-social stressors. The aim of this review is to provide an up-to-date summary of the findings regarding stress system alterations in children and adolescents with ASD. We focus on the variations of stress hormones circadian rhythms, specifically cortisol and alpha-amylase (i.e., a surrogate index of epinephrine/norepinephrine secretion), and on the alterations of stress system responsivity to different stressors. Also, we present imaging and immunological findings that have been associated with stress system dysregulation in children and adolescents with ASD. Finally, we review the pivotal role of HPA axis-ANS coordination, the developmental trajectory of the stress system in ASD, and the possible role of early life stress in the dysregulation of the stress system demonstrated in children and adolescents with ASD. This synthesis will hopefully provide researchers with a foundation for an integrated approach to future research into stress system variations in children and adolescents with ASD.

Theory of mind and hair cortisol in healthy young adults: the moderating effects of childhood trauma

Background: Experiences of negative social interactions and childhood trauma (CT) can lead to aberrant hypothalamic-pituitary-adrenal functions. Poor theory of mind (ToM) ability is related to increased social stress levels; however, studies on the relationship between ToM and cortisol remain scarce. Objective: This study aimed to evaluate the relationship between ToM and the hair cortisol concentration (HCC) in healthy young adults considering the moderating role of CT. Method: A total of 206 healthy young adults were divided into two groups based on an experience of moderate-to-severe childhood trauma (CT+ and CT-). To determine whether CT moderated the relationship between ToM and HCC, moderation analysis was conducted controlling for age, sex, years of education, and scores of perceived stress, depression, and anxiety. Results: CT+ individuals reported higher subjective stress perception and depressive symptoms than CT- individuals, whereas anxiety-related symptoms, ToM, and HCC were not different between the groups. The experience of CT significantly moderated the relationship between ToM and HCC. The association between poorer ToM ability and higher HCC was significant only in CT+ group. Conclusion: CT is a moderator of the association between ToM and HCC, indicating the importance of CT in social cognition and the stress response.

Molecular actions of sex hormones in the brain and their potential treatment use in anxiety disorders

Anxiety disorders are one of the most prevalent mood disorders that can lead to impaired quality of life. Current treatment of anxiety disorders has various adverse effects, safety concerns, or restricted efficacy; therefore, novel therapeutic targets need to be studied. Sex steroid hormones (SSHs) play a crucial role in the formation of brain structures, including regions of the limbic system and prefrontal cortex during perinatal development. In the brain, SSHs have activational and organizational effects mediated by either intracellular or transmembrane G-protein coupled receptors. During perinatal developmental periods, the physiological concentrations of SSHs lead to the normal development of the brain; however, the early hormonal dysregulation could result in various anxiety diorders later in life. Sex differences in the prevalence of anxiety disorders suggest that SSHs might be implicated in their development. In this review, we discuss preclinical and clinical studies regarding the role of dysregulated SSHs signaling during early brain development that modifies the risk for anxiety disorders in a sex-specific manner in adulthood. Moreover, our aim is to summarize potential molecular mechanisms by which the SSHs may affect anxiety disorders in preclinical research. Finally, the potential effects of SSHs in the treatment of anxiety disorders are discussed.

Consequences of Prematurity on Cortisol Regulation and Adjustment Difficulties: A 9-Year Longitudinal Study

A preterm birth represents a stressful event having potentially negative long-term consequences. Thirty-three children born preterm (<33 weeks gestational age) and eleven full-term children participated in a nine-year longitudinal study. Perinatal Risk Inventory (PERI) was used at birth to assess the perinatal stress. Salivary cortisol, collected four times a day over two consecutive days, was measured with radioimmunoassay technique at six months and nine years to assess the hypothalamic-pituitary-adrenal (HPA) axis. Mothers reported post-traumatic symptoms on a self-report questionnaire 12 months after their child's birth and children's adjustment problems at 9 years of child age on the Child Behavior Checklist. Results showed a significant difference in cortisol regulation at nine years between preterm and full-term children but no differences in adjustment problems. Whereas biological factors (i.e., PERI, cortisol regulation at six months) explained cortisol at nine years, maternal post-traumatic symptoms were predictive of adjustment problems in their child. In conclusion, very preterm birth has some long-term consequences on the HPA-axis regulation at nine years. Although cortisol regulation is mostly influenced by biological factors, the presence of maternal post-traumatic symptoms predicts the manifestation of adjustment problems in both groups. This shows the importance of maternal psychological well-being for child development. Further research is needed to understand the exact consequences of premature birth on cortisol regulation and the implication for the child's development and health.

Movement disorders in patients with Rett syndrome: A systematic review of evidence and associated clinical considerations

AIM

This systematic review identified and thematically appraised clinical evidence of movement disorders in patients with Rett syndrome (RTT).

METHOD

Using PRISMA criteria, six electronic databases were searched from inception to April 2021. A thematic analysis was then undertaken on the extracted data to identify potential themes.

RESULTS

Following the thematic analysis, six themes emerged: (i) clinical features of abnormal movement behaviors; (ii) mutational profile and its impact on movement disorders; (iii) symptoms and stressors that impact on movement disorders; (iv) possible underlying neurobiological mechanisms; (v) quality of life and movement disorders; and (vi) treatment of movement disorders. Current guidelines for managing movement disorders in general were then reviewed to provide possible treatment recommendations for RTT.

CONCLUSION

Our study offers an enriched data set for clinical investigations and treatment of fine and gross motor issues in RTT. A detailed understanding of genotype-phenotype relationships of movement disorders allows for more robust genetic counseling for families but can also assist healthcare professionals in terms of monitoring disease progression in RTT. The synthesis also showed that environmental enrichment would be beneficial for improving some aspects of movement disorders. The cerebellum, basal ganglia, alongside dysregulation of the cortico-basal ganglia-thalamo-cortical loop, are likely anatomical targets. A review of treatments for movement disorders also helped to provide recommendations for treating and managing movement disorders in patients with RTT.

Adverse childhood experiences predict reaction to multiple sclerosis diagnosis

Objective

At the time of multiple sclerosis (MS) diagnosis, identifying those at risk for poorer health-related quality of life and emotional well-being can be a critical consideration for treatment planning. This study aimed to test whether adverse childhood experiences predict MS patients’ health-related quality of life and emotional functioning at time of diagnosis and initial course of disease.

Methods

We recruited patients at the time of new MS diagnosis to complete self-report surveys at baseline and a one-year follow-up. Questionnaires included the Adverse Childhood Experiences (ACEs), as well as the MS Knowledge Questionnaire (MSKQ), the 36-Item Short Form Health Survey (SF-36), and Self-Management Screening (SeMaS).

Results

A total of n = 31 participants recently diagnosed with relapsing remitting MS (median EDSS = 1.0, age M = 33.84 ± 8.4 years) completed the study measures. The ACEs significantly predicted health-related quality of life (SF-36) at baseline (Adjusted R² = 0.18, p = 0.011) and follow-up (Adjusted R² = 0.12, p = 0.03), baseline scores on the SeMaS Depression scale (Adjusted R² = 0.19, p = 0.008), as well as follow-up scores on the SeMaS Anxiety (Adjusted R² = 0.19, p = 0.014) and SeMaS Depression (Adjusted R² = 0.14, p = 0.036) scales. Importantly, increased ACEs scores were predictive of increased anxiety at the one-year follow-up assessment, compared to baseline.

Conclusions

Childhood adversity predicts health-related quality of life and emotional well-being at time of MS diagnosis and over the initial course of the disease. Measured using a brief screening inventory (ACEs), routine administration may be useful for identifying patients in need of increased supportive services.

The Role of Stress in Obsessive-Compulsive Disorder: A Narrative Review

Obsessive-compulsive disorder (OCD) has a worldwide prevalence of 2%-3%. Characterized by the presence of either one or two core symptoms-obsessions and compulsions-it generally runs a chronic course and may cause serious functional impairment. Though previously thought to be of psychogenic origin, the pathophysiology of OCD is now understood to be more complex. A multitude of environmental factors have been shown to contribute to the development of OCD, including infection, neonatal complications, childhood trauma, occurrence of stressful events, and brain injury. It has also been proposed that genetic vulnerability may play a role in OCD pathology, although candidate genes have yet to be identified. Likewise, although it is widely accepted that stress plays a role in OCD pathophysiology, the mechanisms remain unclear. Observations from the clinics indicate that stress may serve as both a triggering and aggravating factor, meaning it can prompt symptoms to appear while also contributing to their exacerbation. Additionally, dysfunction of the hypothalamic-pituitary-adrenal axis and impaired stress response have been identified in OCD patients. In this review, we analyze the role of stress in the pathophysiology of OCD, complemented by relevant findings from recent animal studies.

Mice Born to Mothers with Gravida Traumatic Brain Injury Have Distorted Brain Circuitry and Altered Immune Responses

Intimate partner violence (IPV) increases risk of traumatic brain injury (TBI). Physical assaults increase in frequency and intensity during pregnancy. The consequences of TBI during pregnancy (gravida TBI; gTBI) on offspring development is unknown, for which stress and inflammation during pregnancy worsen fetal developmental outcomes. We hypothesized that gTBI would lead to increased anxiety- and depression-related behavior, altered inflammatory responses and gut pathology, and distorted brain circuitry in mixed-sex offspring compared to mice born to control mothers. Pregnant dams received either diffuse TBI or sham injury (control) 12 days post-coitum. We found that male gTBI offspring were principal drivers of the gTBI effects on health, physiology, and behavior. For example, male, but not female, gTBI offspring weighed significantly less at weaning compared to male control offspring. At post-natal day (PND) 28, gTBI offspring had significantly weaker intralaminar connectivity onto layer 5 pre-frontal pyramidal neurons compared to control offspring. Neurological performance on anxiety-like behaviors was decreased, with only marginal differences in depressive-like behaviors, for gTBI offspring compared to control offspring. At PND42 and PND58, circulating neutrophil and monocyte populations were significantly smaller in gTBI male offspring than control male offspring. In response to a subsequent inflammatory challenge at PND75, gTBI offspring had significantly smaller circulating neutrophil populations than control offspring. Anxiety-like behaviors persisted during the immune challenge in gTBI offspring. However, spleen immune response and gut histology showed no significant differences between groups. The results compel further studies to determine the full extent of gTBI on fetal and maternal outcomes.

The putative role of the relaxin-3/RXFP3 system in clinical depression and anxiety: A systematic literature review

The relaxin-3/RXFP3 system is one of several neuropeptidergic systems putatively implicated in regulating the behavioural alterations that characterise clinical depression and anxiety, making it a potential target for clinical translation. Accordingly, this systematic review identified published reports on the role of relaxin-3/RXFP3 signalling in these neuropsychiatric disorders and their behavioural endophenotypes, evaluating evidence from animal and human studies to ascertain any relationship. We searched PubMed, EMBASE, PsycINFO and Google Scholar databases up to February 2021, finding 609 relevant records. After stringent screening, 51 of these studies were included in the final synthesis. There was considerable heterogeneity in study designs and some inconsistency across study outcomes. However, experimental evidence is consistent with an ability of relaxin-3/RXFP3 signalling to promote arousal and suppress depressive- and anxiety-like behaviour. Moreover, meta-analyses of six to eight articles investigating food intake revealed that acute RXFP3 activation had strong orexigenic effects in rats. This appraisal also identified the lack of high-quality clinical studies pertinent to the relaxin-3/RXFP3 system, a gap that future research should attempt to bridge.

Climate Change and Children’s Mental Health: A Developmental Perspective

Climate change is a major global public-health challenge that will have wide-ranging impacts on human psychological health and well-being. Children and adolescents are at particular risk because of their rapidly developing brain, vulnerability to disease, and limited capacity to avoid or adapt to threats and impacts. They are also more likely to worry about climate change than any other age group. Drawing on a developmental life-course perspective, we show that climate-change-related threats can additively, interactively, and cumulatively increase psychopathology risk from conception onward; that these effects are already occurring; and that they constitute an important threat to healthy human development worldwide. We then argue that monitoring, measuring, and mitigating these risks is a matter of social justice and a crucial long-term investment in developmental and mental health sciences. We conclude with a discussion of conceptual and measurement challenges and outline research priorities going forward.

The endocannabinoid system in social anxiety disorder: from pathophysiology to novel therapeutics

Social anxiety disorder (SAD) is a highly prevalent psychiatric disorder that presents with an early age of onset, chronic disease course, and increased risk of psychiatric comorbidity. Current treatment options for SAD are associated with low response rates, suboptimal efficacy, and possible risk of adverse effects. Investigation of new neurobiological mechanisms may aid in the identification of more specific therapeutic targets for the treatment of this disorder. Emerging evidence suggests that the endogenous cannabinoid system, also referred to as the endocannabinoid system (ECS), could play a potential role in the pathophysiology of SAD. This review discusses the known pathophysiological mechanisms of SAD, the potential role of the ECS in this disorder, current drugs targeting the ECS, and the potential of these novel compounds to enhance the therapeutic armamentarium for SAD. Further investigational efforts, specifically in human populations, are warranted to improve our knowledge of the ECS in SAD.

Targeting GluN2B/NO Pathway Ameliorates Social Isolation-Induced Exacerbated Attack Behavior in Mice

Exacerbated attack behavior has a profound socioeconomic impact and devastating social consequences; however, there is no satisfactory clinical management available for an escalated attack behavior. Social isolation (SI) is widespread during this pandemic and may exert detrimental effects on mental health, such as causing heightened attack behavior. To explore the therapeutic approaches that alleviate the SI-induced heightened attack behavior, we utilized pharmacological methods targeting the GluN2B/NO signaling pathway during the attack behavior. Ifenprodil and TAT-9C peptide targeting GluN2B showed that the inhibition of GluN2B mitigated the SI-induced escalated attack behavior and the SI-induced aberrant nitric oxide (NO) level in the brain. Additionally, the potentiation of the NO level by L-arginine reversed the effects of the inhibition of GluN2B. Moreover, we showed that high doses of L-NAME and 7-NI and subeffective doses of L-NAME in combination with ifenprodil or TAT-9C or subeffective doses of 7-NI plus ifenprodil or TAT-9C all decreased the SI-induced escalated attack behavior and reduced the NO level, further supporting the idea that GluN2B/NO signaling is a crucial modulator of the escalated attack behavior.

Childhood maltreatment predicts subsequent anxiety symptoms among Chinese adolescents: the role of the tendency of coping styles

Childhood maltreatment may have an influence on anxiety symptoms and coping styles. This longitudinal study aimed to estimate the prospective associations between different types of childhood maltreatment and anxiety symptoms among Chinese adolescents, with a particular focus on investigating whether these associations vary by the tendency of coping styles. Data were from the Longitudinal Study of Adolescents' Mental and Behavioral Well-being Research. The baseline sample included 1957 participants (response rate: 99.03%) and followed up at 1-year later (n = 1836, retention rate: 93.8%). Anxiety symptoms, childhood maltreatment, the tendency of coping styles, morning cortisol level, depressive symptoms, self-esteem, and other demographics were measured. Overall, the mean age of the baseline students was 13.6 (SD: 1.5) years. The final results showed that childhood emotional abuse (unstandardized β-estimate = 0.13, 95% CI = 0.07-0.18), physical abuse (unstandardized β-estimate = 0.08, 95% CI = 0.01-0.16), and sexual abuse (unstandardized β-estimate = 0.17, 95% CI = 0.04-0.29) were positively associated with anxiety symptoms at follow-up after adjusting for significant covariates at baseline. Additionally, the stratified analyses demonstrated that only among students with negative coping styles, childhood emotional abuse, physical abuse, and sexual abuse were associated with subsequent anxiety symptoms; the differences between the positive and negative coping style strata were significant (P < 0.05). Childhood maltreatment appears to be a predictor of anxiety symptoms among adolescents, and the tendency of coping styles may have a moderating role in these longitudinal associations. The efforts to prevent anxiety symptoms are recommended to be focused on adolescents with the experience of childhood maltreatment and negative coping styles.

Environmental enrichment modulates HPA axis reprogramming in adult male rats exposed to early adolescent stress

Exposure to early stressful events increases susceptibility to post-traumatic stress disorder (PTSD) in adulthood, in which the hypothalamic-pituitary-adrenal (HPA) axis plays a crucial role. Studies have found that environmental enrichment (EE) mitigates the detrimental outcomes of early adversity. However, the HPA-related mechanism remains unclear. In this study, we used the single prolonged stress (SPS) paradigm to explore the long-term effects of early adolescent stress on behavior, HPA axis activity, as well as expression levels of the glucocorticoid receptor (GR), mineralocorticoid receptor (MR), corticotropin-releasing hormone receptor 1 (CRF1R) and CRF2R in the hypothalamus and hippocampus. Meanwhile, the protective effects of EE intervention were examined. We found that adult male rats exposed to adolescent stress showed reduced locomotor activity, increased anxiety-like behaviors, enhanced contextual fear memory, elevated basal plasma ACTH levels, and enhanced HPA negative feedback inhibition, as indicated by decreased plasma ACTH levels in the dexamethasone suppression test (DST). Furthermore, EE normalized the behavioral abnormalities and enhanced HPA negative feedback in stressed rats, possibly through down-regulating GR expression in the hippocampus and hypothalamus. These findings suggested that EE could ameliorate adolescent stress-induced PTSD-like behaviors and aberrant reprogramming of the HPA axis, reducing the risk of developing PTSD in adulthood.

Microbiome and substances of abuse

There is a growing amount of evidence showing a reciprocal relation between the gut microbiota and the brain. Substance use disorders (SUD), which are a major cause of preventable morbidity and mortality worldwide, have an influence on the gut microbiota and on the gut-brain axis. The communication between the microbiota and the brain exists through different pathways: (1) the immune response elicited by bacterial products, coupled with alterations of the intestinal barrier allowing these products to enter the bloodstream, (2) the direct and indirect effects of bacterial metabolites such as short chain fatty acids (SCFAs) or tryptophan on the brain, (3) and the hypothalamic-pituitary-adrenal (HPA) axis, whose peripheral afferents can be influenced by the microbiota, and can in turn activate microglia. Among substances of abuse, alcohol has been the subject of the greatest number of studies in this field. In some but not all patients suffering from alcohol-use-disorder (AUD), alcohol alters the composition of the gut microbiota and the permeability of the intestinal barrier, directly and through dysbiosis. It has also been well demonstrated that alcohol induces a peripheral inflammation; it is still unclear whether it induces a central inflammation, as there are contradictory results in human studies. In animal studies, it has been shown that neuroinflammation increases during alcohol withdrawal. Literature on opioids and stimulants is less numerous. Chronic morphine intake induces dysbiosis, increased intestinal permeability and a probable neuroinflammation, which could explain symptoms such as tolerance, hyperalgesia and deficit in reward behavior. Cocaine induces a dysbiosis and conversely the microbiome can modulate the behavioral response to stimulant drugs. Tobacco cessation is associated with an increase in microbiota diversity. Taken together, the findings of our narrative literature review suggest a bidirectional influence in the pathogenesis of substance use disorders.

The Volatile Oil of Zanthoxylum bungeanum Pericarp Improved the Hypothalamic-Pituitary-Adrenal Axis and Gut Microbiota to Attenuate Chronic Unpredictable Stress-Induced Anxiety Behavior in Rats

Background

Anxiety disorders (ADs) are the most prevalent mental disorders worldwide. Stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis and dysbiosis of gut microbiota seem to contribute to the onset of ADs. This study was designed to investigate the ameliorative effect of volatile oil of Zanthoxylum bungeanum (VOZB) on chronic unpredictable stress (CUS) induced anxiety behavior, as well as the altered HPA axis and gut microbiota.

Methods

Experimental rats were exposed to the CUS for 14 consecutive days. Meanwhile, VOZB was administered at doses of 50, 100 and 200 mg/kg/day for 14 days. The anxiety behavior was evaluated by elevated plus-maze (EPM) and open field (OF). The protein expressions and mRNA levels of corticotropin-releasing hormone (CRH) and glucocorticoid receptor (GR) in hypothalamus was determined, as well the hormone levels of HPA axis in serum. Furthermore, gut microbiota was detected by16S rRNA gene sequencing. The chemical constituents of VOZB were identified by GC-MS analysis.

Results

VOZB treatment (100 and 200 mg/kg/day) increased the ratio of open-arm entries and time in EPM test, as well as the central zone entries and time in OF test. Moreover, VOZB treatment reduced the protein expressions and mRNA levels of CRH, but elevated those of GR in hypothalamus. Similarly, the hormone levels of the HPA axis in serum were decreased by VOZB treatment. Besides, VOZB treatment restored the CUS-induced dysbiosis of gut microbiota, raising the Sobs and Chao indexes, inhibiting Lachnospiraceae, but facilitating Bacteroidales_S24-7_group, Lactobacillaceae, and Prevotellaceae. Additionally, Sobs and Chao indexes were negatively correlated to the serum corticosterone and CRH levels.

Conclusion

VOZB showed an ameliorative effect on CUS-induced anxiety behavior, potentially via inhibiting activation of the HPA axis and restoring the dysbiosis of gut microbiota, thus improving the stress-induced abnormality of the microbiota-gut-brain axis.

Long term effects of early life stress on HPA circuit in rodent models

Adaptation to environmental challenges represents a critical process for survival, requiring the complex integration of information derived from both external cues and internal signals regarding current conditions and previous experiences. The Hypothalamic-pituitary-adrenal axis plays a central role in this process inducing the activation of a neuroendocrine signaling cascade that affects the delicate balance of activity and cross-talk between areas that are involved in sensorial, emotional, and cognitive processing such as the hippocampus, amygdala, Prefrontal Cortex, Ventral Tegmental Area, and dorsal raphe. Early life stress, especially early critical experiences with caregivers, influences the functional and structural organization of these areas, affects these processes in a long-lasting manner and may result in long-term maladaptive and psychopathological outcomes, depending on the complex interaction between genetic and environmental factors. This review summarizes the results of studies that have modeled this early postnatal stress in rodents during the first 2 postnatal weeks, focusing on the long-term effects on molecular and structural alteration in brain areas involved in Hypothalamic-pituitary-adrenal axis function. Moreover, a brief investigation of epigenetic mechanisms and specific genetic targets mediating the long-term effects of these early environmental manipulations and at the basis of differential neurobiological and behavioral effects during adulthood is provided.

Psychosocial and biological risk factors of anxiety disorders in adolescents: a TRAILS report

Anxiety disorders are a common problem in adolescent mental health. Previous studies have investigated only a limited number of risk factors for the development of anxiety disorders concurrently. By investigating multiple factors simultaneously, a more complete understanding of the etiology of anxiety disorders can be reached. Therefore, we assessed preadolescent socio-demographic, familial, psychosocial, and biological factors and their association with the onset of anxiety disorders in adolescence. This study was conducted among 1584 Dutch participants of the TRacking Adolescents' Individual Lives Survey (TRAILS). Potential risk factors were assessed at baseline (age 10-12), and included socio-demographic (sex, socioeconomic status), familial (parental anxiety and depression), psychosocial (childhood adversity, temperament), and biological (body mass index, heart rate, blood pressure, cortisol) variables. Anxiety disorders were assessed at about age 19 years through the Composite International Diagnostic Interview (CIDI). Univariate and multivariate logistic regression analyses were performed with onset of anxiety disorder as a dependent variable and the above-mentioned putative risk factors as predictors. Of the total sample, 25.7% had a lifetime diagnosis of anxiety disorder at age 19 years. Anxiety disorders were twice as prevalent in girls as in boys. Multivariate logistic regression analysis showed that being female (OR = 2.38, p < .01), parental depression and anxiety (OR = 1.34, p = .04), temperamental frustration (OR = 1.31, p = .02) and low effortful control (OR = 0.76, p = .01) independently predicted anxiety disorders. We found no associations between biological factors and anxiety disorder. After exclusion of adolescents with an onset of anxiety disorder before age 12 years, being female was the only significant predictor of anxiety disorder. Being female was the strongest predictor for the onset of anxiety disorder. Psychological and parental psychopathology factors increased the risk of diagnosis of anxiety, but to a lesser extent. Biological factors (heart rate, blood pressure, cortisol, and BMI), at least as measured in the present study, are unlikely to be useful tools for anxiety prevention and intervention strategies.

The functional connectome predicts feeling of stress on regular days and during the COVID-19 pandemic

Although many studies have explored the neural mechanism of the feeling of stress, to date, no effort has been made to establish a model capable of predicting the feeling of stress at the individual level using the resting-state functional connectome. Although individuals may be confronted with multidimensional stressors during the coronavirus disease 2019 (COVID-19) pandemic, their appraisal of the impact and severity of these events might vary. In this study, connectome-based predictive modeling (CPM) with leave-one-out cross-validation was conducted to predict individual perceived stress (PS) from whole-brain functional connectivity data from 817 participants. The results showed that the feeling of stress could be predicted by the interaction between the default model network and salience network, which are involved in emotion regulation and salience attribution, respectively. Key nodes that contributed to the prediction model comprised regions mainly located in the limbic systems and temporal lobe. Critically, the CPM model of PS based on regular days can be generalized to predict individual PS levels during the COVID-19 pandemic, which is a multidimensional, uncontrollable stressful situation. The stability of the results was demonstrated by two independent datasets. The present work not only expands existing knowledge regarding the neural mechanism of PS but also may help identify high-risk individuals in healthy populations.

•

Perceived stress (PS) can be predicated by resting-state functional connectome.

•

PS can be predicated by interaction between default model and salience network.

•

Key nodes of the prediction model located in limbic systems and temporal lobe.

•

psCPM of regular days generalized to predict PS level in the COVID-19 pandemic.

Low hair cortisol concentrations in obsessive compulsive disorder: A cross-sectional study

Recent findings have highlighted the association between changes in the activity of the HPA axis, primarily its end-hormone, cortisol and OCD. However, to date, cortisol levels of OCD patients have been assessed mainly in body fluids, such as serum, saliva or urine, frequently leading to ambiguous results because of their inherent lack of stability. The aim of this study was to investigate time-integrated levels of stress exposure in 32 OCD patients and 32 sex and age-matched healthy controls by measuring endogenous cortisol in hair segments reflecting the last 3 months preceding hair collection. Psychometric parameters, including BDI, FQ, STAI, PSS and ECQ-R, were obtained in all participants; Y-BOCS was performed in the OCD patients. The OCD patients exhibited significantly higher scores in all psychometric instruments administered and lower hair cortisol concentrations than the healthy controls (p = 0.001, r = 0.41). No significant correlations were found between the HCC and the Y-BOCS total scores. After having sorted OCD patients into subtypes, according to the nature of their symptomatology, the "washers/cleaners" category showed the lowest HCC (compared to the "checking/harming", "ordering/symmetry" and "sexual/religious obsessions" categories). The novel finding of chronic low cortisol secretion in OCD patients could be attributed to a possible down-regulation of the HPA axis, as an adaptive response to chronic stress exposure. Given that the OCD subtypes reflect the great heterogeneity in the OCD spectrum, studies with larger samples should extend the investigation of HCC in patients with distinctive symptomatology, so as to develop a basis for better neuroendocrine profiling and understanding of the pathophysiology of OCD. Further work is needed in exploring HPA axis' activity over the natural course and treatments of the disorder.

Hemogram parameters in childhood anxiety disorders: Could anxiety disorders be related with inflammation?

In the etiology of anxiety disorders, immune system and inflammation are suggested to play a role. This study hypothesized that there is a relationship between anxiety disorders and inflammation. This retrospective study included 131 children and adolescents between the ages 6-17 who were diagnosed with anxiety disorders. Control group consisted of 131 healthy children with no history of psychiatric disorders or chronic inflammatory conditions. White blood cell (WBC), neutrophil (NEU), lymphocyte, monocyte, basophil, eosinophil values and other hematological markers were noted. From those values, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), and other ratios were calculated. WBC and NEU values were significantly higher in children and adolescents with anxiety disorder compared to the control group. In addition, NLR, MLR and PLR values were significantly higher than the control group. Other measured parameters and calculated values did not differ between study groups. No statistically significant difference was found between Generalized Anxiety Disorder (GAD) group, Social Anxiety Disorder group and Not Otherwise Specified Anxiety Disorders (AD-NOS) group in terms of hematological markers except RDW-CV. Only RDW-CV was found statistically significantly higher in AD-NOS group compared to GAD. These results show that there is an association between inflammation and anxiety disorders. Also, it is postulated that hematological parameters can be used as a useful marker in the follow-up of patients with anxiety disorders.

An in-depth neurobehavioral characterization shows anxiety-like traits, impaired habituation behavior, and restlessness in male Cryptochrome-deficient mice

Many psychiatric disorders, for example, anxiety, are accompanied by disturbances of circadian rhythms, including disturbed sleep/wake cycles, changes in locomotor activity, and abnormal endocrine function. Conversely, alternations of circadian rhythms are a risk factor for the development of psychiatric disorders. This assumption is supported by animals with clock gene mutations which often display behaviors that resemble human psychiatric disorders. In this study, we performed an in-depth behavioral analysis with male mice lacking the central clock genes Cryptochrome 1 and 2 (Cry1/2^-/- ), which are thus unable to express endogenous circadian rhythms. With wild-type and Cry1/2^-/- mice, we performed an extensive behavioral analysis to study their cognitive abilities, social behavior, and their expression of depression-like and anxiety-like behavior. While Cry1/2^-/- mice showed only mild abnormalities at cognitive and social behavioral levels, they were consistently more anxious than wildtype mice. Anxiety-like behavior was particularly evident in reduced mobility in new environments, altered ability to habituate, compensatory behavior, and consistent restless behavior across many behavioral tests. In line with their anxiety-like behavioral phenotype, Cry1/2^-/- mice have higher c-Fos activity in the amygdala after exposure to an anxiogenic stressor than wild-type mice. In our study, we identified Cry1/2^-/- mice as animals that qualify as a translational mouse model for anxiety disorder in humans because of its consistent behavior of restlessness, increased immobility, and dysfunctional habituation in new environments.