Do common genotypes of FK506 binding protein 5 (FKBP5) moderate the effects of childhood maltreatment on cognition in schizophrenia and healthy controls?

The relationship between genetic liability, childhood maltreatment, and IQ: findings from the EU-GEI multicentric case-control study

This study investigated if the association between childhood maltreatment and cognition among psychosis patients and community controls was partially accounted for by genetic liability for psychosis. Patients with first-episode psychosis (N = 755) and unaffected controls (N = 1219) from the EU-GEI study were assessed for childhood maltreatment, intelligence quotient (IQ), family history of psychosis (FH), and polygenic risk score for schizophrenia (SZ-PRS). Controlling for FH and SZ-PRS did not attenuate the association between childhood maltreatment and IQ in cases or controls. Findings suggest that these expressions of genetic liability cannot account for the lower levels of cognition found among adults maltreated in childhood.

Associations of psychiatric disease and ageing with FKBP5 expression converge on superficial layer neurons of the neocortex

Identification and characterisation of novel targets for treatment is a priority in the field of psychiatry. FKBP5 is a gene with decades of evidence suggesting its pathogenic role in a subset of psychiatric patients, with potential to be leveraged as a therapeutic target for these individuals. While it is widely reported that FKBP5/FKBP51 mRNA/protein (FKBP5/1) expression is impacted by psychiatric disease state, risk genotype and age, it is not known in which cell types and sub-anatomical areas of the human brain this occurs. This knowledge is critical to propel FKBP5/1-targeted treatment development. Here, we performed an extensive, large-scale postmortem study (n = 1024) of FKBP5/1, examining neocortical areas (BA9, BA11 and ventral BA24/BA24a) derived from subjects that lived with schizophrenia, major depression or bipolar disorder. With an extensive battery of RNA (bulk RNA sequencing, single-nucleus RNA sequencing, microarray, qPCR, RNAscope) and protein (immunoblot, immunohistochemistry) analysis approaches, we thoroughly investigated the effects of disease state, ageing and genotype on cortical FKBP5/1 expression including in a cell type-specific manner. We identified consistently heightened FKBP5/1 levels in psychopathology and with age, but not genotype, with these effects strongest in schizophrenia. Using single-nucleus RNA sequencing (snRNAseq; BA9 and BA11) and targeted histology (BA9, BA24a), we established that these disease and ageing effects on FKBP5/1 expression were most pronounced in excitatory superficial layer neurons of the neocortex, and this effect appeared to be consistent in both the granular and agranular areas examined. We then found that this increase in FKBP5 levels may impact on synaptic plasticity, as FKBP5 gex levels strongly and inversely correlated with dendritic mushroom spine density and brain-derived neurotrophic factor (BDNF) levels in superficial layer neurons in BA11. These findings pinpoint a novel cellular and molecular mechanism that has potential to open a new avenue of FKBP51 drug development to treat cognitive symptoms in psychiatric disorders.

Genetically engineered mouse models of FK506-binding protein 5

FK506 binding protein 51 (FKBP51) is a molecular chaperone that influences stress response. In addition to having an integral role in the regulation of steroid hormone receptors, including glucocorticoid receptor, FKBP51 has been linked with several biological processes including metabolism and neuronal health. Genetic and epigenetic alterations in the gene that encodes FKBP51, FKBP5, are associated with increased susceptibility to multiple neuropsychiatric disorders, which has fueled much of the research on this protein. Because of the complexity of these processes, animal models have been important in understanding the role of FKBP51. This review examines each of the current mouse models of FKBP5, which include whole animal knockout, conditional knockout, overexpression, and humanized mouse models. The generation of each model and observational details are discussed, including behavioral phenotypes, molecular changes, and electrophysiological alterations basally and following various challenges. While much has been learned through these models, there are still many aspects of FKBP51 biology that remain opaque and future studies are needed to help illuminate these current gaps in knowledge. Overall, FKBP5 continues to be an exciting potential target for stress-related disorders.

Association of early life stress and cognitive performance in patients with schizophrenia and healthy controls

As core symptoms of schizophrenia, cognitive deficits contribute substantially to poor outcomes. Early life stress (ELS) can negatively affect cognition in patients with schizophrenia and healthy controls, but the exact nature of the mediating factors is unclear. Therefore, we investigated how ELS, education, and symptom burden are related to cognitive performance. The sample comprised 215 patients with schizophrenia (age, 42.9 ± 12.0 years; 66.0 % male) and 197 healthy controls (age, 38.5 ± 16.4 years; 39.3 % male) from the PsyCourse Study. ELS was assessed with the Childhood Trauma Screener (CTS). We used analyses of covariance and correlation analyses to investigate the association of total ELS load and ELS subtypes with cognitive performance. ELS was reported by 52.1 % of patients and 24.9 % of controls. Independent of ELS, cognitive performance on neuropsychological tests was lower in patients than controls (p < 0.001). ELS load was more closely associated with neurocognitive deficits (cognitive composite score) in controls (r = -0.305, p < 0.001) than in patients (r = -0.163, p = 0.033). Moreover, the higher the ELS load, the more cognitive deficits were found in controls (r = -0.200, p = 0.006), while in patients, this correlation was not significant after adjusting for PANSS. ELS load was more strongly associated with cognitive deficits in healthy controls than in patients. In patients, disease-related positive and negative symptoms may mask the effects of ELS-related cognitive deficits. ELS subtypes were associated with impairments in various cognitive domains. Cognitive deficits appear to be mediated through higher symptom burden and lower educational level.

Environmental Risk Factors and Cognitive Outcomes in Psychosis: Pre-, Perinatal, and Early Life Adversity

Risk for psychosis begins to accumulate as early as the fetal period through exposure to obstetric complications like fetal hypoxia, maternal stress, and prenatal infection. Stressors in the postnatal period, such as childhood trauma, peer victimization, and neighborhood-level adversity, further increase susceptibility for psychosis. Cognitive difficulties are among the first symptoms to emerge in individuals who go on to develop a psychotic disorder. We review the relationship between pre-, perinatal, and early childhood adversities and cognitive outcomes in individuals with psychosis. Current evidence shows that the aforementioned environmental risk factors may be linked to lower overall intelligence and executive dysfunction, beginning in the premorbid period and persisting into adulthood in individuals with psychosis. It is likely that early life stress contributes to cognitive difficulties in psychosis through dysregulation of the body's response to stress, causing changes such as increased cortisol levels and chronic immune activation, which can negatively impact neurodevelopment. Intersectional aspects of identity (e.g., sex/gender, race/ethnicity), as well as gene-environment interactions, likely inform the developmental cascade to cognitive difficulties throughout the course of psychotic disorders and are reviewed below. Prospective studies of birth cohorts will serve to further clarify the relationship between early-life environmental risk factors and cognitive outcomes in the developmental course of psychotic disorders. Specific methodological recommendations are provided for future research.

Regulatory functions of FKBP5 intronic regions associated with psychiatric disorders

The FKBP5 gene codifies a co-chaperone protein associated with the modulation of glucocorticoid receptor interaction involved in the adaptive stress response. The FKBP5 intracellular concentration affects the binding affinity of the glucocorticoid receptor (GR) to glucocorticoids (GCs). This gene has glucocorticoid response elements (GREs) located in introns 2, 5 and 7, which affect its expression. Recent studies have examined GRE activity and the effects of genetic variants on transcript efficiency and their contribution to susceptibility to behavioral disorders. Epigenetic changes and environmental factors can influence the effects of these allele-specific variants, impacting the response to GCs of the FKBP5 gene. The main epigenetic mark investigated in FKBP5 intronic regions is DNA methylation, however, few studies have been performed for all GREs located in these regions. One of the major findings was the association of low DNA methylation levels in the intron 7 of FKBP5 in patients with psychiatric disorders. To date, there are no reports of DNA methylation in introns 2 and 5 of the gene associated with diagnoses of psychiatric disorders. This review highlights what has been discovered so far about the relationship between polymorphisms and epigenetic targets in intragenic regions, and reveals the gaps that need to be explored, mainly concerning the role of DNA methylation in these regions and how it acts in psychiatric disease susceptibility.

Polymorphisms in the FKBP5 gene are associated with attention deficit and hyperactivity disorder in Korean children

Attention deficit hyperactivity disorder (ADHD) is a common and heritable childhood psychiatric disorder. Recently, many studies reported a down-regulated hypothalamus-pituitary-adrenal axis (HPA-axis) with low cortisol levels in children with ADHD. The FK506 binding protein 5 or FKBP5 gene regulates the negative feedback of the HPA-axis, and genetic variants in this gene showed an association with ADHD. We investigated the genetic association between FKBP5 gene polymorphisms and susceptibility to ADHD in Korean children. We conducted a case-control study with 150 ADHD children and 322 controls. Genotyping of FKBP5 rs9394309 and rs7748266 was performed by using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP). Our results showed that rs7748266 polymorphism has significant genotype (p = 0.021) and allele (p = 0.009) frequency differences between children with ADHD and the control group. CT genotype [odds ratio (OR) 1.70, 95 % confidence interval (CI) 1.134-2.540, p = 0.010] and T allele (OR 1.54, 95 % CI 1.114-2.117, p = 0.009) were associated with increased risk of ADHD. In addition, dominant (p = 0.006) and over-dominant genetic (p = 0.016) models showed significant associations with ADHD. In the stratified analysis, a significant result was obtained from the girl samples (p = 0.048). The OR of the girls with ADHD with CT genotype was 2.29 (95 % CI 1.170-4.469, p = 0.014). In contrast to rs7748266 polymorphism, rs9394309 polymorphism did not show any significant result (p > 0.05). Haplotype analysis also revealed a significant difference of the TG haplotype for rs7748266 - rs9394309 (p = 0.028, global haplotype association p-value of 0.0091). Conclusively, we confirmed that FKBP5 gene polymorphisms were associated with ADHD in Korean children. These results suggested that FKBP5 may factor in the development of ADHD.

The Impact of Childhood Trauma on Developing Bipolar Disorder: Current Understanding and Ensuring Continued Progress

Childhood trauma (CT) has been repeatedly linked to earlier onset and greater severity of bipolar disorder (BD) in adulthood. However, such knowledge is mostly based on retrospective and cross-sectional studies in adults with BD. The first objective of this selective review is to characterize the short-term effects of CT in the development of BD by focusing on studies in young people. The second objective is to describe the longer-term consequences of CT by considering studies with adult participants. This review first outlines the most prominent hypotheses linking CT exposure and the onset of BD. Then, it summarizes the psychological and biological risk factors implicated in the development of BD, followed by a discussion of original studies that investigated the role of CT in young people with early-onset BD, youths at increased risk of developing BD, or young people with BD with a focus on subclinical and clinical outcome measures. The review considers additional biological and psychological factors associated with a negative impact of CT on the long-term course of BD in later adulthood. Finally, we discuss how the integration of information of CT can improve ongoing early identification of BD and mitigate severe clinical expression in later adulthood.

Adverse Childhood Experiences and Methylation of the FKBP5 Gene in Patients with Psychotic Disorders

Altered methylation of the FKBP5 gene has been observed in various mental disorders and attributed to the effects of adverse childhood experiences (ACEs). However, the level of FKBP5 methylation has not been investigated in patients with psychotic disorders. Therefore, in this study we aimed to determine the FKBP5 methylation in patients with psychosis and controls, taking into account the effects of ACEs. Participants were 85 patients with psychotic disorders, including first-episode psychosis (FEP) patients and acutely relapsed schizophrenia (SCZ-AR) patients, as well as 56 controls. The level of four CpG sites at the FKBP5 gene was determined in the peripheral blood leukocytes using pyrosequencing. After controlling for potential confounding factors, the level of FKBP5 methylation at one out of four tested CpG sites was significantly lower in FEP patients compared to other groups of participants. Significant main effects of parental antipathy and sexual abuse on the level of FKBP5 methylation were observed at the differentially methylated CpG site. Participants reporting this category of ACEs had significantly lower levels of FKBP5 methylation at this CpG site. Lower levels of FKBP5 methylation were associated with better cognitive performance and higher functional capacity in patients with psychosis. In controls, lower methylation of FKBP5 was related to worse performance of immediate memory and language skills. Our findings suggest that hypomethylation of the FKBP5 appears at early stages of psychosis and might be associated with a history of ACEs as well as less severe clinical manifestation.

Hypothalamic-pituitary-adrenal axis-related genes and cognition in major mood disorders and schizophrenia: a systematic review

Hypothalamic-pituitary-adrenal (HPA) axis dysregulation and cognitive deficits are two well-characterized endophenotypes present in different serious mental illnesses (SMIs), including major depressive disorder, bipolar disorder and schizophrenia. Our aim was to study the influence of genetic and epigenetic variations in HPA axis-related genes on cognitive performance in clinical samples, including patients with major mood disorders and schizophrenia. A systematic search was performed using PubMed (Medline), PsycINFO and Scopus databases. The systematic review identified 12 studies dealing with HPA-related genes and cognition in samples including patients with SMIs, focusing on single nucleotide polymorphism (SNP) variants, while no studies analysing epigenetic variations were found. The results suggest different and specific effects on the cognitive performance of SNP variants in the HPA axis-related genes studied, as well as interactions with traumatic experiences. There was high heterogeneity in the studied samples, genes analysed, and cognitive tasks evaluated. The relationship between HPA-related genes and cognition in SMIs is still largely unknown, and further studies including larger samples and epigenetic variations are needed.

Childhood Trauma and Neurocognition in Adults With Psychotic Disorders: A Systematic Review and Meta-analysis

BACKGROUND

Characterizing the link between childhood trauma and adult neurocognitive function in psychosis is crucial for improving the fields understanding of how early environmental risk factors impact the presentation of the disorder. To date, the literature has been inconsistent: meta-analytic synthesis is lacking, and it is unclear whether specific cognitive functions are affected.

METHODS

A meta-analysis was performed on a total of 3315 subjects with a psychotic disorder. The links between childhood trauma, overall neurocognitive function, and four cognitive subdomains (working memory, executive function, verbal/visual memory, and attention/processing speed) were examined. Relevant sample characteristics and methodological moderators were tested. The strength of the association between trauma and overall neurocognition in individuals with psychotic disorders was also compared to that of healthy controls.

RESULTS

Among individuals with psychotic disorders, there was a significant association between overall cognition and childhood trauma, r = -.055; 95% CI = -0.09, -0.02, P = .002. There was also a modest, negative relationship between childhood trauma and working memory, r = -.091; 95% CI = -0.15, -0.03, P = .002. Moderators did not have a significant effect on these analyses. Further, the association between childhood trauma and neurocognition was significantly stronger in healthy controls compared to patients with a psychotic disorder.

CONCLUSION

A small negative association was found between overall cognition and childhood trauma in individuals with psychotic disorders. Results suggest the association is less strong for individuals with a psychotic disorder compared to healthy populations. Findings are informative for prominent etiological models of psychosis.

Allostatic load index and its clinical correlates at various stages of psychosis

Accumulating evidence indicates systemic biological dysregulations in patients with psychosis that have been conceptualized as the "allostatic load" (AL) index. We aimed to investigate the AL index in 37 subjects at familial high risk of psychosis (FHRP), 42 first-episode psychosis (FEP) patients, 25 acutely relapsed schizophrenia (SCZ-AR) patients and 42 healthy controls (HCs), taking into account psychopathology and cognitive impairment. The AL index was calculated based on 15 biomarkers (cardiovascular markers, anthropometric measures, inflammatory markers, glucose homeostasis parameters, lipids and steroids). Cognition was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The AL index was significantly higher in patients with psychosis and FHR-P individuals compared to HCs. Patients with FEP and FHR-P individuals had similar AL index. Moreover, the AL index was significantly higher in SCZ-AR patients compared to other groups of participants. Higher AL index was associated with more severe general psychopathology and depressive symptoms, lower scores of attention (total score, digit span and digit coding tasks) and semantic fluency, as well as worse general functioning in patients with psychosis. There was a significant negative correlation between the AL index and the scores of attention (total score and digit coding task) in FHR-P individuals. No significant correlations between the AL index and cognition were found in HCs. Our results indicate that biological dysregulations, captured by the AL index, appear already in FHR-P individuals and progress with psychotic exacerbations. Elevated AL index might contribute to cognitive impairments in FHR-P individuals and patients with psychosis.

Gene and environment interplay in cognition: Evidence from twin and molecular studies, future directions and suggestions for effective candidate gene x environment (cGxE) research

Last decade of molecular research in the field of cognitive science has shown that no single approach can give satisfactory results as far as gene hunt is concerned. Cohesive theory of gene-environment interaction seems to be a rational idea for bridging the gap in our knowledge of disorders involving cognitive deficit. It may even be helpful to some extent in resolving issues of missing heritability. We review the current state of play in the area of cognition at genetic and environmental fronts. Evidence of apparent gene-environment (GxE) interactions from various studies has been mentioned with the aim of redirecting the focus of research community towards studying such interactions with the help of sensitive designs and molecular techniques. We re-evaluate candidate gene-environment research in order to emphasize its potential if carried out strategically.

Childhood Trauma in Schizophrenia: Current Findings and Research Perspectives

Schizophrenia is a severe neuropsychiatric disorder with persistence of symptoms throughout adult life in most of the affected patients. This unfavorable course is associated with multiple episodes and residual symptoms, mainly negative symptoms and cognitive deficits. The neural diathesis-stress model proposes that psychosocial stress acts on a pre-existing vulnerability and thus triggers the symptoms of schizophrenia. Childhood trauma is a severe form of stress that renders individuals more vulnerable to developing schizophrenia; neurobiological effects of such trauma on the endocrine system and epigenetic mechanisms are discussed. Childhood trauma is associated with impaired working memory, executive function, verbal learning, and attention in schizophrenia patients, including those at ultra-high risk to develop psychosis. In these patients, higher levels of childhood trauma were correlated with higher levels of attenuated positive symptoms, general symptoms, and depressive symptoms; lower levels of global functioning; and poorer cognitive performance in visual episodic memory end executive functions. In this review, we discuss effects of specific gene variants that interact with childhood trauma in patients with schizophrenia and describe new findings on the brain structural and functional level. Additive effects between childhood trauma and brain-derived neurotrophic factor methionine carriers on volume loss of the hippocampal subregions cornu ammonis (CA)4/dentate gyrus and CA2/3 have been reported in schizophrenia patients. A functional magnetic resonance imaging study showed that childhood trauma exposure resulted in aberrant function of parietal areas involved in working memory and of visual cortical areas involved in attention. In a theory of mind task reflecting social cognition, childhood trauma was associated with activation of the posterior cingulate gyrus, precuneus, and dorsomedial prefrontal cortex in patients with schizophrenia. In addition, decreased connectivity was shown between the posterior cingulate/precuneus region and the amygdala in patients with high levels of physical neglect and sexual abuse during childhood, suggesting that disturbances in specific brain networks underlie cognitive abilities. Finally, we discuss some of the questionnaires that are commonly used to assess childhood trauma and outline possibilities to use recent biostatistical methods, such as machine learning, to analyze the resulting datasets.

The role of childhood trauma in cognitive performance in schizophrenia and bipolar disorder - A systematic review

Childhood trauma (CT) has repeatedly been associated with cognitive deficits in patients with psychosis but many inconsistencies have been reported so that the nature of the relationship remains unclear. The purpose of this review was to better characterize the contribution of CT to cognitive deficits by considering the type, severity and frequency of childhood traumatic events and their relationships with psychosis at all stages.

Relevant studies were identified via electronic and manual literature searches and included original studies that investigated the relationship between CT and higher cognitive performance or social cognitive performance in patients with schizophrenia, bipolar disorder and psychosis at all stages of the illness stages (i.e. ultra-high risk, first episode or chronic phase).

Overall, a majority of studies reported that patients who experienced CT displayed deficits in general cognitive ability compared to patients with psychosis without such a history. Associations between CT and other cognitive function were more mixed. When comparing patient groups, the association between CT and cognitive function was more inconsistent in patients with chronic schizophrenia than in healthy participants, ultra-high risk individuals, first-episode patients and patients with chronic bipolar disorder.

In understanding the variability in the reported relationships between CT and cognition across study populations, we highlight the variety of questionnaires used and discuss the likelihood of there being differences in cognitive function based on specific stressors, severity and frequency. Finally, we consider future research steps that may shed light on psychobiological mechanisms underlying CT and cognitive performance in patients with psychosis.

Interactions Between Variation in Candidate Genes and Environmental Factors in the Etiology of Schizophrenia and Bipolar Disorder: a Systematic Review

Schizophrenia and bipolar disorder (BD) are complex and multidimensional disorders with high heritability rates. The contribution of genetic factors to the etiology of these disorders is increasingly being recognized as the action of multiple risk variants with small effect sizes, which might explain only a minor part of susceptibility. On the other site, numerous environmental factors have been found to play an important role in their causality. Therefore, in recent years, several studies focused on gene × environment interactions that are believed to bridge the gap between genetic underpinnings and environmental insults. In this article, we performed a systematic review of studies investigating gene × environment interactions in BD and schizophrenia spectrum phenotypes. In the majority of studies from this field, interacting effects of variation in genes encoding catechol-O-methyltransferase (COMT), brain-derived neurotrophic factor (BDNF), and FK506-binding protein 5 (FKBP5) have been explored. Almost consistently, these studies revealed that polymorphisms in COMT, BDNF, and FKBP5 genes might interact with early life stress and cannabis abuse or dependence, influencing various outcomes of schizophrenia spectrum disorders and BD. Other interactions still require further replication in larger clinical and non-clinical samples. In addition, future studies should address the direction of causality and potential mechanisms of the relationship between gene × environment interactions and various categories of outcomes in schizophrenia and BD.

A BRIEF INTRODUCTION TO THE NEUROGENETICS OF COGNITION-EMOTION INTERACTIONS

Neuroscience research has demonstrated that cognition, emotion, and their dynamic interactions emerge from complex and flexible patterns of activity across distributed neural circuits. A parallel branch of research in genetics has begun to identify common variation in the human DNA sequence (i.e., genome) that may shape individual differences in cognition-emotion interactions by altering molecular and cellular pathways that modulate the activity of these neural circuits. Here we provide a brief introduction to such neurogenetics research and how it may usefully inform our understanding of the biological mechanisms through which dynamic cognition-emotion interactions emerge and, subsequently, help shape normal and abnormal behavior.

Interaction between FKBP5 gene and childhood trauma on psychosis, depression and anxiety symptoms in a non-clinical sample

BACKGROUND

Childhood trauma has been associated with a heightened risk for presenting clinical and non-clinical psychopathology in adulthood. Genes related with the stress response, such as the FK506 binding protein 51 (FKBP5), are plausible candidates moderating the effects of childhood trauma on the emergence of such symptoms later on. The present study aimed to explore the moderating role of FKBP5 genetic variability on the association of different types of childhood trauma with subclinical psychosis, depression and anxiety in a non-clinical sample.

METHODS

Schizotypy, psychotic-like experiences, depression and anxiety symptoms and childhood trauma were assessed in 808 young adults. Two FKBP5 haplotypic blocks were detected: block 1 (rs3800373 - rs9296158 - rs1360780) and block 2 (rs9470080 - rs4713916). Subjects were classified in two groups according to whether they carried or not the risk haplotype previously described in the literature (block 1: CAT and block 2: TA). Linear regression analyses were used to study (i) the main effects of childhood trauma and FKBP5 haplotype blocks and (ii) their interaction effects on the mentioned forms of psychopathology.

RESULTS

All childhood trauma scales, except sexual abuse, were associated with schizotypy, psychotic-like experiences, depression and anxiety symptoms. None of the analysed symptoms was associated with the main effects of FKBP5 genetic variability. However an interaction effect between block 1 and physical abuse was observed on anxiety, with lower scores in CAT carriers. This effect was driven by SNP 1 and 2. Moreover, an interaction effect between block 2 and physical abuse was identified on the variables tapping depressive and anxiety symptoms. Specifically, non-TA carrier subjects who were exposed to physical abuse were found to be at higher risk for depressive and anxiety symptoms. These effects were driven by SNP 5. No interaction effect was observed for the other variables.

CONCLUSIONS

Our data suggest that exposure to childhood physical abuse may increase the risk for sub-clinical depressive and anxiety symptoms depending on FKBP5 genetic variability. Further research is needed to better elucidate the role of FKBP5 on mental health in clinical and non-clinical cohorts.

The emerging role of the FKBP5 gene polymorphisms in vulnerability-stress model of schizophrenia: further evidence from a Serbian population

Increased reactivity to stress is observed in patients with schizophrenia spectrum disorders and their healthy siblings in comparison with the general population. Additionally, higher levels of neuroticism, as a proposed psychological measure of stress sensitivity, increase the risk of schizophrenia. HPA axis dysregulation is one of the possible mechanisms related to the vulnerability-stress model of schizophrenia, and recent studies revealed a possible role of the functional genetic variants of FK506-binding protein 51 (FKBP5) gene which modulate activity of HPA axis. The purpose of the present study was to investigate impact of FKBP5 on schizophrenia in Serbian patients and to explore relationship between genetic variants and neuroticism by using the case-sibling-control design. In 158 subjects, we measured psychotic experiences, childhood trauma and neuroticism. Nine single-nucleotide polymorphisms (rs9295158, rs3800373, rs9740080, rs737054, rs6926133, rs9380529, rs9394314, rs2766533 and rs12200498) were genotyped. The genetic influence was modeled using logistic regression, and the relationship between genetic variants and neuroticism was assessed by linear mixed model. Our results revealed genetic main effect of FKBP5 risk alleles (A allele of rs9296158 and T allele of rs3800373) and AGTC "risk" haplotype combination (rs9296158, rs3800373, rs9470080 and rs737054, respectively) on schizophrenia, particularly when childhood trauma was set as a confounding factor. We confirmed strong relationship between neuroticism and psychotic experiences in patients and siblings and further showed relationship between higher levels of neuroticism and FKBP5 risk variants suggesting potential link between biological and psychosocial risk factors. Our data support previous findings that trauma exposure shapes FKBP5 impact on schizophrenia.

Neurobiological Development in the Context of Childhood Trauma

Neurobiological systems may be particularly susceptible to deleterious impact of childhood trauma, and the impact of childhood trauma on development and subsequent functional outcomes across the lifespan has been well-documented. The current review addresses the neurobiological impact of exposure to interpersonal trauma in childhood in the context of executive function, emotion regulation, and dissociation/interoceptive awareness. Subsequent risk for PTSD and depression is also discussed. The pathway of risk from childhood trauma to these cognitive, emotional, and psychiatric outcomes is addressed in terms of potential structural and functional alterations within the hippocampus, prefrontal cortex, and amygdala resulting from chronic or repeated activation of the hypothalamic-pituitary-adrenal (HPA) axis and its interaction with and influence on genetic and epigenetic processes during sensitive periods of development. Implications for practice are discussed.

Toward a unified theory of childhood trauma and psychosis: A comprehensive review of epidemiological, clinical, neuropsychological and biological findings

There is a growing body of research focused on the relationship between childhood trauma and the risk of developing psychosis. Numerous studies, including many large-scale population-based studies, controlling for possible mediating variables, provide persuasive evidence of a dose-response association and are indicative of a causal relationship. Existing evidence supports the specificity model, showing differential associations between particular adversities and clinical symptoms, with cumulative adversity causing less favorable clinical and functional outcomes in psychotic patients. To date, several psychological and biological models have been proposed to search for underlying developmental trajectories leading to the onset of psychosis, influencing psychopathological manifestation and negative functional outcomes due to a history of childhood trauma. In this article, we provide a unified review on the relationship between childhood trauma and psychosis by integrating results of epidemiological, clinical, neuropsychological and biological studies. The question whether psychosis with a positive history of childhood trauma should be considered as a new psychotic phenotype, requiring specific therapeutic interventions, warrants further investigation.