Stress sensitization to depression following childhood adversity: Moderation by HPA axis and serotonergic multilocus profile scores

HPA-axis multilocus genetic interaction with stress life events in predicting changes in adolescent suicidal ideation

BACKGROUND

Research suggests that genetic variants linked to the hypothalamic-pituitary-adrenal (HPA) axis moderate the association between stressors and change in suicidal ideation, but examining gene-environment interactions with single polymorphisms limits power. This study investigates how interactions between stressful life events and HPA-axis polygenic risk predict changes in suicidal ideation.

METHODS

A sample of 760 adolescents (Mage = 14.15 ± 0.63 years; 54.6 % girls) was followed up over two years. The polygenic risk was assessed using a multilocus genetic profile score (MGPS) based on the additive effects of six HPA-axis candidate genes (SKS2, NR3C1, NR3C2, FKBP5). Participants were categorized into distinct trajectories of suicidal ideation based on time-varying changes in their ideation scores. Multivariate logistic regression analyses were conducted to identify predictors of trajectory membership.

RESULTS

(1) Five distinct trajectories of suicidal ideation were identified: resistance (52.7 %), persistence (13.1 %), delayed (11.4 %), remission (15.6 %), and relapsing (7.2 %). (2) The combination of HPA-axis MGPS and SLEs showed good predictive accuracy for suicidal ideation trajectories, as indicated by the area under the ROC curve. (3) The interaction between all six stressful life events and HPA-axis MGPS is more predictive of developing persistent trajectories of suicidal ideation. Meanwhile, HPA-axis MGPS interacted with factors such as interpersonal relationships, academic pressure, and loss to better predict the delayed and relapsing suicidal ideation compared to the resistance group.

CONCLUSIONS

This study suggests that genetic variants associated with the HPA axis exert a polygenic, additive effect on the relationship between stressful life events and longitudinal increases in suicidal ideation.

The effects of childhood maltreatment, recent interpersonal and noninterpersonal stress, and HPA-axis multilocus genetic variation on prospective changes in adolescent depressive symptoms: A multiwave longitudinal study

Based on a multiwave, two-year prospective design, this study is the first to examine the extent to which multilocus hypothalamic-pituitary-adrenal axis (HPA axis)-related genetic variants, childhood maltreatment, and recent stress jointly predicted prospective changes in adolescent depressive symptoms. A theory-driven multilocus genetic profile score (MGPS) was calculated to combine the effects of six common polymorphisms within HPA-axis related genes (CRHR1, NR3C1, NR3C2, FKBP5, COMT, and HTR1A) in a sample of Chinese Han adolescents (N = 827; 50.2% boys; Mage = 16.45 ± 1.36 years). The results showed that the three-way interaction of HPA-axis related MGPS, childhood maltreatment and recent interpersonal, but not noninterpersonal, stress significantly predicted prospective changes in adolescent depressive symptoms. For adolescents with high but not low HPA-axis related MGPS, exposure to severe childhood maltreatment predisposed individuals more vulnerable to recent interpersonal stress, exhibiting greater prospective changes in adolescent depressive symptoms. The findings provide preliminary evidence for the cumulative risk mechanism regarding gene-by-environment-by-environment (G × E1 × E2) interactions that underlie the longitudinal development of adolescent depressive symptoms and show effects specific to interpersonal stress.

Stress sensitization to psychological adjustment following childhood adversity: Moderation by serotonergic multilocus genetic variation

BACKGROUND

Exposure to adverse childhood experiences may heighten adolescents' sensitivity to stress, which influences their psychological adjustment over their lifetimes. Some research indicates that serotonergic genetic variation moderates how environmental stressors impact psychological adjustment. However, there are recognized limitations in examining gene-environment interactions using only single polymorphisms.

METHODS

The present study employed a multilocus genetic profile score (MGPS) approach to measure serotonergic genetic variations and examines their interaction with childhood abuse and friendship quality as predictors of the outcomes of psychological adjustment (depressive symptoms and sleep problems) in an adolescent sample (14.15 ± 0.63 years; N = 525).

RESULTS

Serotonergic genetic factors moderated stress sensitivity induced by adverse childhood experiences. Adolescent psychological adjustment appeared to result from interactions between genetics and the environments. These findings were further supported by rigorous significance testing and sensitivity analyses.

CONCLUSION

The results highlight the strong utility of using MGPS to investigate gene-environment-environment interactions related to adolescent psychological adjustment.

Early-life stress sensitizes response to future stress: Evidence and mechanisms

Early-life stress sensitizes individuals to additional stressors and increases lifetime risk for mood and anxiety disorders. Research in both human populations and rodent models of early-life stress have sought to determine how different types of stressors contribute to vulnerability, and whether there are developmental sensitive periods for such effects. Although differences in the type and timing of rodent early-life stress paradigms have led to differences in specific behavioral outcomes, this complexity is present among humans as well. Robust rodent research now shows how early-life stress increases sensitivity to future stressors at behavioral, neural circuit, and molecular levels. These recent discoveries are laying the foundation for translation to more effective interventions relevant for those who experienced childhood stress and trauma.

Maternal adverse childhood experiences and lifetime experiences of racial discrimination: Associations with current household hardships and intergenerational health

Growing evidence shows parents' exposure to adverse childhood experiences (ACEs) and lifetime experiences of racial discrimination (EOD) negatively impacts not only their own health, but also their children's health. ACEs and EOD can be conceptualized as a reflection of shared underlying adversities and structural injustices that manifest in inequitable educational and employment opportunities and differential treatment by public policies and programs that impede parents' capacity to support their families. Therefore, a potentially important, but underexplored, mechanism of effects of parent ACEs and EOD on the next generation is through effects on household material hardships. Using cross-sectional survey data collected from 1629 mothers of young children aged <4 years during pediatric healthcare visits in four US cities (Baltimore, MD; Boston, MA; Little Rock, AR; Philadelphia, PA), we examined individual and joint associations of mothers' ACEs and EOD with their health and their children's health, as well as household-level material hardships. In demographics-adjusted Poisson and multinomial logistic regression models, mothers who had experienced high ACEs, high EOD, or high combined ACE-EOD reported more household hardships and were less likely to report that they and their young children were in good health. Mediation analyses showed evidence that associations with maternal health were partially mediated by household hardships. Our results suggest that maternal ACEs and EOD may undermine maternal and child health via household hardships, along with other potential mechanisms. Counteracting downstream effects of these adversities requires timely intervention on multiple levels, including addressing remediable household hardships. Ultimately, a focus on achieving equity comprehensively through policy design and implementation is needed to realize the full potential of public policies for supporting family and child health.

Polygene by environment interactions predicting depressive outcomes

Depression is a major public health problem with a continued need to uncover its etiology. Current models of depression contend that gene-by-environment (G × E) interactions influence depression risk, and further, that depression is polygenic. Thus, recent models have emphasized two polygenic approaches: a hypothesis-driven multilocus genetic profile score (MGPS; "MGPS × E") and a polygenic risk score (PRS; "PRS × E") derived from genome-wide association studies (GWAS). This review for the first time synthesizes current knowledge on polygene by environment "P × E" interaction research predicting primarily depression-related outcomes, and in brief, neurobiological outcomes. The "environment" of focus in this project is stressful life events. It further discusses findings in the context of differential susceptibility and diathesis-stress theories-two major theories guiding G × E work. This synthesis indicates that, within the MGPS literature, polygenic scores based on the serotonin system, the HPA axis, or across multiple systems, interact with environmental stress exposure to predict outcomes at multiple levels of analyses and most consistently align with differential susceptibility theory. Depressive outcomes are the most studied, but neuroendocrine, and neuroimaging findings are observed as well. By contrast, vast methodological differences between GWAS-based PRS studies contribute to mixed findings that yield inconclusive results.

The Interaction of Polygenic Susceptibility to Stress and Childhood Adversity Dimensions Predicts Longitudinal Trajectories of Stress-Sensitivity

Stress-sensitivity (SS) is considered a psychobiological trait possibly resulting from the interaction of genetic and environmental factors (GxE). This study examined whether the interaction of SS-related genetic markers with interview-based dimensions of childhood adversity predicted longitudinal trajectories of low versus high SS. Participants were nonclinically-ascertained young adults comprising normative and elevated scores on schizotypy. SS trajectories were defined in a previous report based on three prospective assessments (23.5, 25, 28 years-old) of both retrospective (Perceived Stress Scale; PSS) and momentary (Experience Sampling Methodology; ESM) stress ratings. A total of n = 177 and n = 165 participants with PSS and ESM stress-sensitivity trajectories, respectively, as well as genetic data, were included in the study. GxE effects between a SS Polygenic Risk Score (PRS-SS) and a Genetic Risk Score of the Hypothalamic Pituitary Adrenal axis (GRS-HPA) with childhood adversity dimensions (Intrafamilial Adversity, Threat and Deprivation) on SS trajectories were examined. Threat was the most consistent predictor of persistently high SS. PRS-SS moderated the association of Threat with high-PSS. GRS-HPA moderated the effects of all adversity dimensions on high-PSS. The interaction of PRS-SS with Deprivation and GRS-HPA with Intrafamilial Adversity predicted trajectories of momentary social stress, but the effects were driven by those with lower genetic susceptibility. Genetic-HPA-axis moderates the effects of all adversity dimensions on persistent SS trajectories, as well as PRS-SS and Threat, particularly for retrospective stress measure. The findings highlight the complex interplay between GxE factors and suggest that PSS may better capture SS trait. Including biologically-meaningful GRS indexing SS and adversity dimensions in future studies using comprehensive stress measures would enhance our knowledge on high SS susceptibility and its relationship with diverse psychopathological outcomes.

The interplay of dopaminergic genotype and parent-child relationship in relation to intra-individual response time variability in preschoolers: A replication study

Intra-individual response time variability (IIRTV) during cognitive performance is increasingly recognized as an important indicator of attentional control (AC) and related brain region function. However, what determinants contribute to preschoolers' IIRTV received little attention. The present study explored the interaction of dopaminergic polygenic composite score (DPCS) and the parent-child relationship in relation to preschoolers' IIRTV. In the initial sample, 452 preschoolers (M age = 5.17, SD = 0.92) participated in the study. The modified Flanker task was used to evaluate children's IIRTV and their parents were requested to complete the Parent-Child Relationship Scale to assess the parent-child relationship (closeness/conflict). DNA data were extracted from children's saliva samples, and a DPCS was created by the number of COMT, DAT1, and DRD2 alleles associated with lower dopamine levels. Results showed that DPCS significantly interacted with the parent-child closeness to impact preschoolers' IIRTV. Specifically, preschoolers with higher DPCS exhibited lower IIRTV under higher levels of the parent-child closeness, and greater IIRTV under lower levels of the parent-child closeness compared to those with lower DPCS, which supported the differential susceptibility theory (DST). A direct replication attempt with 280 preschoolers (M age = 4.80, SD = 0.86) was conducted to investigate whether the results were in accordance with our exploratory outcomes. The interactive effect of DPCS and the parent-child closeness on IIRTV was confirmed. Additionally, the significant interactive effect of DPCS and the parent-child conflict on IIRTV was found in the replication study. The findings indicate that preschoolers' IIRTV, as an indicator of AC and related brain region function, is influenced by the interactions of dopaminergic genotypes and the parent-child relationship. RESEARCH HIGHLIGHTS: We investigated the Gene × Environment mechanism to underline the intra-individual response time variability as an indicator of attentional control (AC) in Chinese preschoolers. Dopaminergic polygenic composite score (COMT, DAT1, and DRD2) interacted with the parent-child relationship to predict preschoolers' intra-individual reaction time variability. A direct replication attempt has been conducted, and the results were in accordance with our exploratory outcomes, which increased the credibility of the present findings. The findings highlight the importance of considering precursors, including polygenic and environmental factors, which contribute to the development of early cognitive performance such as AC.

Environment by environment interactions (ExE) differ across genetic backgrounds (ExExG)

While the terms "gene-by-gene interaction" (GxG) and "gene-by-environment interaction" (GxE) are widely recognized in the fields of quantitative and evolutionary genetics, "environment-byenvironment interaction" (ExE) is a term used less often. In this study, we find that environmentby-environment interactions are a meaningful driver of phenotypes, and moreover, that they differ across different genotypes (suggestive of ExExG). To support this conclusion, we analyzed a large dataset of roughly 1,000 mutant yeast strains with varying degrees of resistance to different antifungal drugs. Our findings reveal that the effectiveness of a drug combination, relative to single drugs, often differs across drug resistant mutants. Remarkably, even mutants that differ by only a single nucleotide change can have dramatically different drug × drug (ExE) interactions. We also introduce a new framework that more accurately predicts the direction and magnitude of ExE interactions for some mutants. Understanding how ExE interactions change across genotypes (ExExG) is crucial not only for modeling the evolution of pathogenic microbes, but also for enhancing our knowledge of the underlying cell biology and the sources of phenotypic variance within populations. While the significance of ExExG interactions has been overlooked in evolutionary and population genetics, these fields and others stand to benefit from understanding how these interactions shape the complex behavior of living systems.

Cumulative Genetic Scores Interact with Maternal and Paternal Parenting in Predicting Parent-Adolescent Cohesion and Conflict

Previous research concerning the interplay between genetics and parenting in the development of the parent-child relationship during adolescence has been extremely scarce, predominantly adopting single-gene designs. This limited body of work has largely overlooked the distinct effects of maternal and paternal roles, as well as potential gender differences. Additionally, existing gene-by-environment (G × E) studies have mainly concentrated on adverse environmental factors and associated negative outcomes, somewhat neglecting positive environments and outcomes. The present study examined the interactions of cumulative genetic scores (CGS, dopamine receptor D2 TaqIA and oxytocin receptor gene rs53576 polymorphisms) with both positive and negative parenting on parent-adolescent cohesion and conflict. Furthermore, this study aimed to ascertain with which gene-environment model the potential G × E interactions would align. A total of 745 Chinese Han adolescents (Mage = 13.36 ± 0.96 years; 46.8% girls) from grades 7 to 9 participated in this study. Results revealed a significant effect of CGS and negative maternal parenting on mother-adolescent conflict among males, consistent with the weak differential susceptibility model. As CGS increased, the effects of negative maternal parenting on mother-son conflict were magnified. These findings have implications for the timing and focus of interventions aimed at improving parent-adolescent relationships.

Adverse childhood experience and depression: the role of gut microbiota

Depression is the most common psychiatric disorder that burdens modern society heavily. Numerous studies have shown that adverse childhood experiences can increase susceptibility to depression, and depression with adverse childhood experiences has specific clinical-biological features. However, the specific neurobiological mechanisms are not yet precise. Recent studies suggest that the gut microbiota can influence brain function and behavior associated with depression through the "microbe-gut-brain axis" and that the composition and function of the gut microbiota are influenced by early stress. These studies offer a possibility that gut microbiota mediates the relationship between adverse childhood experiences and depression. However, few studies directly link adverse childhood experiences, gut microbiota, and depression. This article reviews recent studies on the relationship among adverse childhood experiences, gut microbiota, and depression, intending to provide insights for new research.

Serotonergic multilocus genetic variation moderates the association between interpersonal relationship and adolescent depressive symptoms

BACKGROUND

Research suggests that genetic variants linked to serotonin functioning moderate the association between environmental stressors and depressive symptoms, but examining gene-environment interactions with single polymorphisms limits power.

METHODS

A multilocus genetic profile score (MGPS) approach to measuring serotonergic multilocus genetic variation and examined interactions with interpersonal relationship, insomnia with depressive symptoms as outcomes in an adolescent sample (average age = 14.15 ± 0.63 years since first measurement; range: 13 to 15).

RESULTS

(1) interpersonal relationship predicted adolescent depressive symptoms; (2) insomnia mediated the effect of interpersonal relationships on adolescent depressive symptoms; (3) the THP2 gene rs4570625 polymorphism G allele was a key risk factor for depressive symptom, and the MGPS moderated the effects of teacher-student relationship and insomnia on adolescent depressive symptom. Specifically, as the MGPS increased, the effects of insomnia on adolescent depressive symptom were enhanced; further, when the MGPS score increased, the effect of teacher-student relationship on depression showed a similar phenomenon with an increased slope and enhanced prediction; and (4) the results of sensitivity analysis showed that multilocus genetic interaction with the environment had a better explanatory power and stability for depression than single polymorphism studies.

CONCLUSION

MGPS provides substantial power to examine gene-environmental interactions linked to affective outcomes among adolescents.

Linking individual variability in functional brain connectivity to polygenic risk in major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is a highly heterogeneous disease, which brings great difficulties to clinical diagnosis and therapy. Its mechanism is still unknown. Prior neuroimaging studies mainly focused on mean differences between patients and healthy controls (HC), largely ignoring individual differences between patients.

METHODS

This study included 112 MDD patients and 93 HC subjects. Resting-state functional MRI data were obtained to examine the patterns of individual variability of brain functional connectivity (IVFC). The genetic risk of pathways including dopamine, 5-hydroxytryptamine (5-HT), norepinephrine (NE), hypothalamic-pituitary-adrenal (HPA) axis, and synaptic plasticity was assessed by multilocus genetic profile scores (MGPS), respectively.

RESULTS

The IVFC pattern of the MDD group was similar but higher than that in HCs. The inter-network functional connectivity in the default mode network contributed to altered IVFC in MDD. 5-HT, NE, and HPA pathway genes affected IVFC in MDD patients. The age of onset, duration, severity, and treatment response, were correlated with IVFC. IVFC in the left ventromedial prefrontal cortex had a mediating effect between MGPS of the 5-HT pathway and baseline depression severity.

LIMITATIONS

Environmental factors and differences in locations of functional areas across individuals were not taken into account.

CONCLUSIONS

This study found MDD patients had significantly different inter-individual functional connectivity variations than healthy people, and genetic risk might affect clinical manifestations through brain function heterogeneity.

Family-based care buffers the stress sensitizing effect of early deprivation on executive functioning difficulties in adolescence

We examined whether family care following early-life deprivation buffered the association between stressful life events (SLEs) and executive functioning (EF) in adolescence. In early childhood, 136 institutionally reared children were randomly assigned to foster care or care-as-usual; 72 never-institutionalized children served as a comparison group. At age 16 years, adolescents (n = 143; 54% female; 67.1% Romanian) self-reported recent SLEs, completed a battery of memory and EF tasks, and completed a go/nogo task in which mediofrontal theta power (MFTP) was measured using electroencephalogram. More independent SLEs predicted lower EF and more dependent SLEs predicted lower MFTP, but only among adolescents with prolonged early deprivation. Findings provide preliminary evidence that family care following early deprivation may facilitate resilience against stress during adolescence on EF.

Associations Between Complex Trauma Exposure in Childhood/Adolescence and Psychopathology in Older Age: The Role of Stress Coping and Coping Self-Perception

Complex trauma exposure in childhood and/or adolescence is common and has repeatedly been linked to mental ill-health across the lifespan. While the correlates of complex trauma and mental health are well-studied in individuals up to middle adulthood, correlates in older adulthood, as well as potential mediators of this relationship, such as stress coping, are insufficiently studied. Therefore, this study aimed to (a) examine the mental health of Swiss older adults affected by complex trauma exposure in childhood and/or adolescence, in comparison to non-affected individuals; and (b) to examine the potential mediating role of coping strategies and coping self-perception. Data from N = 257 participants (complex trauma [CT] group: n = 161; M _age = 69.66 years, 48.4% female; non-complex trauma [nCT] group: n = 96; M _age = 72.49 years, 42.7% female) were assessed using self-report questionnaires and a clinical interview. The CT group presented with significantly more current and lifetime mental health disorders, more disadvantageous coping strategies, and significantly lower coping self-perception, compared to the nCT group. Mediation analyses revealed that maladaptive coping and coping self-perception were relevant mediators of the relationship between complex trauma exposure and psychopathology. Results suggest that complex trauma exposure in childhood and/or adolescence can have a lasting impact on mental health in later life and can be negatively associated with stress coping. Findings emphasize the relevance of a lifespan perspective in research and clinical practice for addressing consequences of complex trauma exposure.

Gut-Brain-Microbiota Axis: Antibiotics and Functional Gastrointestinal Disorders

Gut microbiota composition and function are major areas of research for functional gastrointestinal disorders. There is a connection between gastrointestinal tract and central nervous system and this is mediated by neurotransmitters, inflammatory cytokines, the vagus nerve and the hypothalamic-pituitary-adrenal axis. Functional gastrointestinal disorders are prevalent diseases affecting more than one third of the population. The etiology of these disorders is not clarified. Visceral hyperalgesia is the main hypothesis for explaining clinical symptoms, however gut-brain axis disorder is a new terminology for functional disorders. In this review, microbiota-gut-brain axis connection pathways and related disorders are discussed. Antibiotics are widely used in developed countries and recent evidence indicates antibiotic-induced dysbiosis as an important factor for functional disorders. Antibiotics exert negative effects on gut microbiota composition and functions. Antibiotic-induced dysbiosis is a major factor for occurrence of post-infectious irritable bowel syndrome. Cognitive and mood disorders are also frequent in functional gastrointestinal disorders. Animal and human trials show strong evidence for the causal relationship between gut microbiota and brain functions. Therapeutic implications of these newly defined pathogenic pathways are also discussed.