Interplay between childhood trauma and BDNF val66met variants on blood BDNF mRNA levels and on hippocampus subfields volumes in schizophrenia spectrum and bipolar disorders

Childhood trauma and treatment resistance in first-episode psychosis: Investigating the role of premorbid adjustment and duration of untreated psychosis

BACKGROUND

Early identification of treatment non-response in first-episode psychosis (FEP) is essential to outcome. Despite indications that exposure to childhood trauma (CT) can have adverse effects on illness severity, its impact on treatment non-response and the interplay with other pre-treatment characteristics is sparsely investigated. We use a lack of clinical recovery as an early indicator of treatment resistance to investigate the relationship between CT and treatment resistance status at one-year follow-up and the potential mediation of this effect by other pre-treatment characteristics.

METHODS

This prospective one-year follow-up study involved 141 participants recruited in their first year of treatment for a schizophrenia-spectrum disorder. We investigated clinical status, childhood trauma (CT), premorbid adjustment (PA), and duration of untreated psychosis (DUP) at baseline and clinical status at one-year follow-up. Ordinal regression analyses were conducted to investigate how PA and DUP affected the relationship between CT and one-year outcome in FEP.

RESULTS

45 % of the FEP sample reported moderate to severe CT, with significantly higher levels of CT in the early treatment resistant group compared to participants with full or partial early recovery. Ordinal regression analysis showed that CT was a significant predictor of being in a more severe outcome group (OR = 4.59). There was a partial mediation effect of PA and a full mediation effect of DUP on the effect of CT on outcome group membership.

DISCUSSION

Our findings indicate that reducing treatment delays may mitigate the adverse effects of CT on clinical outcomes and support the inclusion of broad trauma assessment in FEP services.

The neural, stress hormone and inflammatory correlates of childhood deprivation and threat in psychosis: A systematic review

Childhood adversity increases the risk of developing psychosis, but the biological mechanisms involved are unknown. Disaggregating early adverse experiences into core dimensions of deprivation and threat may help to elucidate these mechanisms. We therefore systematically searched the literature investigating associations between deprivation and threat, and neural, immune and stress hormone systems in individuals on the psychosis spectrum. Our search yielded 74 articles, from which we extracted and synthesized relevant findings. While study designs were heterogeneous and findings inconsistent, some trends emerged. In psychosis, deprivation tended to correlate with lower global cortical volume, and some evidence supported threat-related variation in prefrontal cortex morphology. Greater threat exposure was also associated with higher C-reactive protein, and higher and lower cortisol measures. When examined, associations in controls were less evident. Overall, findings indicate that deprivation and threat may associate with partially distinct biological mechanisms in the psychosis spectrum, and that associations may be stronger than in controls. Dimensional approaches may help disentangle the biological correlates of childhood adversity in psychosis, but more studies are needed.

Childhood trauma and bipolar affective disorder: Is there a linkage?

Bipolar affective disorder (BPAD) is a major psychiatric illness impairing the quality of life. The etiology of BPAD is influenced by different factors possibly related to gene-environment interactions. Approximately 30% to 50% of individuals with BPAD have experienced some traumatic event in childhood. Serious adverse experiences that children may suffer early in life are often described as childhood trauma (CT). It includes physical, emotional, and sexual abuse and physical and emotional neglect. CT is linked with an elevated risk of developing BPAD. Childhood adversities play a role in modulating the early onset of illness, increased number of depressive episodes, increased suicide attempts, and other clinical severity of BPAD. Hospital-based studies comprising heterogeneous populations had researched the specific role of each trauma subtype as a predisposing factor for BPAD. Identifying and addressing CT through early intervention methods may prevent the future development of chronic disorders like BPAD. This review article is an attempt to explore and highlight the existing literature regarding the association of different subtypes of CT with BPAD.

Pathways from threat exposure to psychotic symptoms in youth: The role of emotion recognition bias and brain structure

BACKGROUND

Research supports an association between threatening experiences in childhood and psychosis. It is possible that early threat exposure disrupts the development of emotion recognition (specifically, producing a bias for facial expressions relating to threat) and the brain structures subserving it, contributing to psychosis development.

METHODS

Using data from the Philadelphia Neurodevelopmental Cohort, we examined associations between threat exposure and both the misattribution of facial expressions to fear/anger in an emotion recognition task, and gray matter volumes in key emotion processing regions. Our sample comprised youth with psychosis spectrum symptoms (N = 304), control youth (N = 787), and to evaluate specificity, youth with internalizing symptoms (N = 92). The moderating effects of group and sex were examined.

RESULTS

Both the psychosis spectrum and internalizing groups had higher levels of threat exposure than controls. In the total sample, threat exposure was associated with lower left medial prefrontal cortex (mPFC) volume but not misattributions to fear/anger. The effects of threat exposure did not significantly differ by group or sex.

CONCLUSIONS

The findings of this study provide evidence for an effect of threat exposure on mPFC morphology, but do not support an association between threat exposure and a recognition bias for threat-related expressions, that is particularly pronounced in psychosis. Future research should investigate factors linking transdiagnostic alterations related to threat exposure with psychotic symptoms, and attempt to clarify the mechanisms underpinning emotion recognition misattributions in threat-exposed youth.

The interplay between sexual abuse and inflammation, oxidative stress, and DNA damage in drug-naïve panic disorder patients

Although accumulating evidence suggests an interplay between child abuse and inflammatory processes and the pathophysiology of mental disorders, few studies have investigated the cellular mechanisms related to this matter. Furthermore, no studies to date have evaluated cytokine, oxidative stress, and DNA damage levels in drug-naïve panic disorder (PD) patients and their possible association with childhood trauma. The aim of the present study was to determine the levels of the proinflammatory interleukin (IL)-1B, the oxidative stress marker TBARS, and  8-hydroxy-2' -deoxyguanosine (8-OHdG; representing DNA damage) in drug-naïve PD patients compared to controls. Furthermore, this investigation aimed to determine whether early-life trauma could predict peripheral levels of the previously mentioned markers in unmedicated PD patients. This work showed that drug-naïve PD patients presented elevated levels of TBARS and IL-1B but not 8-OHdG compared to healthy controls. In addition, sexual abuse during childhood was associated with increased levels of IL-1B in PD patients. Our findings suggest that the microglial NLRP3 inflammasome complex might be activated in drug-naïve PD patients. This study is the first to associated sexual abuse with increased levels of IL-1B in drug-naïve PD patients and to demonstrate that this population presents high concentrations of oxidative stress and inflammation markers but not DNA damage markers when compared to healthy controls. Independent replication of these findings would support further clinical trials of inflammasome inhibitory drugs in PD patients, which could lead to effective novel treatments for people with PD and contribute to elucidating pathophysiological differences depending on trauma exposure in the immune disturbances accompanying PD.

Exploring the mediation of DNA methylation across the epigenome between childhood adversity and First Episode of Psychosis-findings from the EU-GEI study

ABTRACT

Studies conducted in psychotic disorders have shown that DNA-methylation (DNAm) is sensitive to the impact of Childhood Adversity (CA). However, whether it mediates the association between CA and psychosis is yet to be explored. Epigenome wide association studies (EWAS) using the Illumina Infinium-Methylation EPIC array in peripheral blood tissue from 366 First-episode of psychosis and 517 healthy controls was performed. Adversity scores were created for abuse, neglect and composite adversity with the Childhood Trauma Questionnaire (CTQ). Regressions examining (I) CTQ scores with psychosis; (II) with DNAm EWAS level and (III) between DNAm and caseness, adjusted for a variety of confounders were conducted. Divide-Aggregate Composite-null Test for the composite null-hypothesis of no mediation effect was conducted. Enrichment analyses were conducted with missMethyl package and the KEGG database. Our results show that CA was associated with psychosis (Composite: OR = 1.68; p = <0.001; abuse: OR = 2.16; p < 0.001; neglect: OR = 2.27; p = <0.001). None of the CpG sites significantly mediated the adversity-psychosis association after Bonferroni correction (p < 8.1 × 10-8). However, 28, 34 and 29 differentially methylated probes associated with 21, 27, 20 genes passed a less stringent discovery threshold (p < 5 × 10-5) for composite, abuse and neglect respectively, with a lack of overlap between abuse and neglect. These included genes previously associated to psychosis in EWAS studies, such as PANK1, SPEG TBKBP1, TSNARE1 or H2R. Downstream gene ontology analyses did not reveal any biological pathways that survived false discovery rate correction. Although at a non-significant level, DNAm changes in genes previously associated with schizophrenia in EWAS studies may mediate the CA-psychosis association. These results and associated involved processes such as mitochondrial or histaminergic disfunction, immunity or neural signalling requires replication in well powered samples. The lack of overlap between mediating genes associated with abuse and neglect suggests differential biological trajectories linking CA subtypes and psychosis.

Synergistic effects of childhood adversity and polygenic risk in first-episode psychosis: the EU-GEI study

BACKGROUND

A history of childhood adversity is associated with psychotic disorder, with an increase in risk according to the number of exposures. However, it is not known why only some exposed individuals go on to develop psychosis. One possibility is pre-existing polygenic vulnerability. Here, we investigated, in the largest sample of first-episode psychosis (FEP) cases to date, whether childhood adversity and high polygenic risk scores for schizophrenia (SZ-PRS) combine synergistically to increase the risk of psychosis, over and above the effect of each alone.

METHODS

We assigned a schizophrenia-polygenic risk score (SZ-PRS), calculated from the Psychiatric Genomics Consortium (PGC2), to all participants in a sample of 384 FEP patients and 690 controls from the case-control component of the EU-GEI study. Only participants of European ancestry were included in the study. A history of childhood adversity was collected using the Childhood Trauma Questionnaire (CTQ). Synergistic effects were estimated using the interaction contrast ratio (ICR) [odds ratio (OR)exposure and PRS - ORexposure - ORPRS + 1] with adjustment for potential confounders.

RESULTS

There was some evidence that the combined effect of childhood adversities and polygenic risk was greater than the sum of each alone, as indicated by an ICR greater than zero [i.e. ICR 1.28, 95% confidence interval (CI) -1.29 to 3.85]. Examining subtypes of childhood adversities, the strongest synergetic effect was observed for physical abuse (ICR 6.25, 95% CI -6.25 to 20.88).

CONCLUSIONS

Our findings suggest possible synergistic effects of genetic liability and childhood adversity experiences in the onset of FEP, but larger samples are needed to increase precision of estimates.

Gray matter alterations in adolescent major depressive disorder and adolescent bipolar disorder

BACKGROUND

Gray matter volume (GMV) alterations in several emotion-related brain areas are implicated in mood disorders, but findings have been inconsistent in adolescents with major depressive disorder (MDD) or bipolar disorder (BD).

METHODS

We conducted a comprehensive meta-analysis of 35 region-of-interest (ROI) and 18 whole-brain voxel-based morphometry (VBM) MRI studies in adolescent MDD and adolescent BD, and indirectly compared the results in the two groups. The effects of age, sex, and other demographic and clinical scale scores were explored using meta-regression analysis.

RESULTS

In the ROI meta-analysis, right putamen volume was decreased in adolescents with MDD, while bilateral amygdala volume was decreased in adolescents with BD compared to healthy controls (HC). In the whole-brain VBM meta-analysis, GMV was increased in right middle frontal gyrus and decreased in left caudate in adolescents with MDD compared to HC, while in adolescents with BD, GMV was increased in left superior frontal gyrus and decreased in limbic regions compared with HC. MDD vs BD comparison revealed volume alteration in the prefrontal-limbic system.

LIMITATION

Different clinical features limit the comparability of the samples, and small sample size and insufficient clinical details precluded subgroup analysis or meta-regression analyses of these variables.

CONCLUSIONS

Distinct patterns of GMV alterations in adolescent MDD and adolescent BD could help to differentiate these two populations and provide potential diagnostic biomarkers.

Hippocampal subfields, daily stressors, and resting cortisol in individuals at clinical high-risk for psychosis

INTRODUCTION

The hippocampus, comprised of functionally distinct subfields, both regulates stress and is affected by it during psychosis pathogenesis. Hippocampal abnormalities are evident across psychosis spectrum and are associated with aberrant cortisol levels and greater environmental stressors exposure. These associations, particularly at the subfield-level, are poorly understood in individuals at clinical high-risk (CHR) for psychosis. This represents a significant literature gap given this critical pathogenetic period is characterized by an interplay between environmental stressors and biological susceptibility.

METHODS

A total of 121 participants including 51 CHR (mean age=18.61) and 70 healthy controls (HC; mean age=18.3) were enrolled in the study. Participants completed a structural scan, salivary cortisol assays, and a self-report measure assessing distress from daily stressors exposure (DSI). Hippocampal subfield segmentation was conducted using Freesurfer.

RESULTS

Smaller hippocampal subfields were associated with greater stress levels. Greater DSI was associated with lower volumes in CA1 (r = -0.38) and CA2/3 (r = -0.29), but not in CA4/DG (r = -0.28), presubiculum (r = -0.09), or subiculum (r = -0.17). Higher resting cortisol was associated with lower volumes in presubiculum (r = -0.4) but not subiculum (r = -0.22), CA1 (r = 0.08), CA2/3 (r = 0.1), or CA4/DG (r = -0.005). Regressions indicated effects for CA1 and DSI (β = 0.57, p = .03) and presubiculum and cortisol (β = 0.61, p = .02) are specific to CHR participants relative to HCs.

CONCLUSIONS

The findings provided insights into links between stress and brain vulnerability during psychosis-risk period. Regional differences highlighted potentially different mechanisms by which stress impacts specific subfields. Presubiculum may be more susceptible to the impact of early stress on HPA-axis and cornu amonis to acute stressors.

Retrospectively assessed childhood trauma experiences are associated with illness severity in mental disorders adjusted for symptom state

Converging evidence suggests that childhood trauma is a causal factor in schizophrenia (SZ) and in bipolar disorders (BD). Here, we investigated whether retrospective reports are associated with severity of illness, independent of current symptom state in a large sample of participants with SZ or BD. We included 1260 individuals (SZ [n = 461], BD [n = 352]), and healthy controls; HC [n = 447]) recruited from the same catchment area. A history of childhood trauma was obtained with the Childhood Trauma Questionnaire (CTQ). Diagnosis and episodes were obtained with the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I). Clinical symptoms (state) were assessed with the Positive and Negative Syndrome scale (PANSS), the Calgary Depression Scale (CDSS). Trait related illness characteristics were assessed with age at illness onset, number of episodes, and lifetime suicide attempts. Patients who reported multiple types of childhood trauma experiences had significantly more severe illness course including an earlier illness onset, more mood episodes, and increased risk of at least one suicide attempt, also after adjusting for current symptom state. Retrospective assessed childhood trauma experiences are associated with illness severity in mental disorders adjusted for symptom state. Our results strengthen the role of childhood trauma in development of psychopathology.

Genetic Specificity of Hippocampal Subfield Volumes, Relative to Hippocampal Formation, Identified in 2148 Young Adult Twins and Siblings

The hippocampus is a complex brain structure with key roles in cognitive and emotional processing and with subregion abnormalities associated with a range of disorders and psychopathologies. Here we combine data from two large independent young adult twin/sibling cohorts to obtain the most accurate estimates to date of genetic covariation between hippocampal subfield volumes and the hippocampus as a single volume. The combined sample included 2148 individuals, comprising 1073 individuals from 627 families (mean age = 22.3 years) from the Queensland Twin IMaging (QTIM) Study, and 1075 individuals from 454 families (mean age = 28.8 years) from the Human Connectome Project (HCP). Hippocampal subfields were segmented using FreeSurfer version 6.0 (CA4 and dentate gyrus were phenotypically and genetically indistinguishable and were summed to a single volume). Multivariate twin modeling was conducted in OpenMx to decompose variance into genetic and environmental sources. Bivariate analyses of hippocampal formation and each subfield volume showed that 10%-72% of subfield genetic variance was independent of the hippocampal formation, with greatest specificity found for the smaller volumes; for example, CA2/3 with 42% of genetic variance being independent of the hippocampus; fissure (63%); fimbria (72%); hippocampus-amygdala transition area (41%); parasubiculum (62%). In terms of genetic influence, whole hippocampal volume is a good proxy for the largest hippocampal subfields, but a poor substitute for the smaller subfields. Additive genetic sources accounted for 49%-77% of total variance for each of the subfields in the combined sample multivariate analysis. In addition, the multivariate analyses were sufficiently powered to identify common environmental influences (replicated in QTIM and HCP for the molecular layer and CA4/dentate gyrus, and accounting for 7%-16% of total variance for 8 of 10 subfields in the combined sample). This provides the clearest indication yet from a twin study that factors such as home environment may influence hippocampal volumes (albeit, with caveats).

Neurotrophic factors, childhood trauma and psychiatric disorders: A systematic review of genetic, biochemical, cognitive and imaging studies to identify potential biomarkers

BACKGROUND

Exposure to traumatic experience represents one of the key environmental factors influencing the risk for several psychiatric disorders, in particular when suffered during childhood, a critical period for brain development, characterized by a high level of neuroplasticity. Abnormalities affecting neurotrophic factors might play a fundamental role in the link between childhood trauma (CT) and early life stress (ELS) and psychiatric disorders.

METHODS

A systematic review was conducted, considering genetic, biochemical and expression studies along with cognitive and brain structure imaging investigations, based on PubMed and Web of Science databases (available up until November 2021), to identify potential neuroplasticity related biomarkers associated both with CT/ELS and psychiatric disorders. The search was followed by data abstraction and study quality assessment (Newcastle-Ottawa Scale).

RESULTS

103 studies met our eligibility criteria. Among them, 65 were available for genetic, 30 for biochemical and 3 for mRNA data; 45 findings were linked to specific symptomatology/pathologies, 16 with various cognitive functions, 19 with different brain areas, 6 on methylation and 36 performed on control subjects for the Brain Derived Neurotrophic Factor (BDNF); whereas 4 expression/biochemical studies covered Neurotrophin 4 (NT-4), Vascular Endothelium Growth Factor (VEGF), Epidermal Growth Factor (EGF), Fibroblast Growth Factor (FGF), and Transforming Growth Factor β1 (TGF-β1).

LIMITATIONS

Heterogeneity of assessments (biological, psychological, of symptomatology, and CT/ELS), age range and ethnicity of samples for BDNF studies; limited studies for other neurotrophins.

CONCLUSIONS

Results support the key role of BDNF (in form of Met allele) as biomarker, both at genetic and biochemical level, in mediating the effect of CT/ELS in psychiatric disorders, passing through specific cognitive functions and specific brain region architecture.

The effects of developmental trauma on theory of mind and its relationship to psychotic experiences: A behavioural study

BACKGROUND

Developmental psychological trauma induces vulnerability to psychosis. However, the mechanisms underlying this association are poorly understood. Impairments in Theory of Mind (ToM) have been observed in adult survivors of developmental trauma and individuals with psychosis. ToM is therefore a candidate mechanism underlying the association between developmental trauma and psychosis.

METHODS

We used a computerised version of the Director task - where a participant is instructed by a confederate to move an object around a 4 × 4 grid, whilst taking account of whether these objects are visible to a confederate who instructs the participant - to investigate impairments in ToM in 209 participants (age: M = 37.8, SD=13.6; 56% female). Participants were divided into a) developmental trauma-positive (DT+) and control groups (DT-) based on their history of developmental trauma and b) then further into subclinical (S) and healthy groups (H) as based on psychotic experiences indexed by the CAPE-P15. After exclusion, the numbers in each group were: DT+H (47), DT+S (84), DT-H (54), DT-S (12). (Total: 197).

RESULTS

Developmental trauma exposure was associated with psychotic experiences (OR: 7.89, p < .001), which remained significant after controlling for demographic and clinical confounds (adjusted R² = 0.452, R² change = 0.0184, p = .009). Participants with developmental trauma (F_{1, 194}) = 5.46, p = .020, ηp² = 0.027) and participants more prone to psychotic experiences (F_{1, 194}) = 4.71, p = .031, ηp² = 0.024) demonstrated significantly lower accuracy on the Director task relative to their respective control, after controlling for the effects of age.

CONCLUSIONS

ToM deficits are associated with self-reported developmental trauma and psychotic experiences. Further work is needed to explore these relationships further and whether they represent generalised or specific effect effects on developmental trauma and psychopathological domains.

Childhood trauma is associated with poorer social functioning in severe mental disorders both during an active illness phase and in remission

BACKGROUND

Impaired social functioning is a core feature of schizophrenia spectrum (SZS) and bipolar spectrum disorders (BDS). Childhood traumatic events are more frequent in SZS and BDS than in healthy individuals (HC), and could represent a cumulative risk for reduced social functioning beyond experiencing ongoing clinical symptoms.

METHODS

The study comprised 1039 individuals (SZS [n = 348]; BDS [n = 262], and HC [n = 429]). Childhood trauma and level of social functioning was assessed by the Childhood Trauma Questionnaire (CTQ) and the Social Functioning Scale (SFS), respectively. Diagnosis was obtained by the Structured Clinical Interview (SCID) for the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV).

RESULTS

Patients had poorer social functioning (F = 819.18, p ˂ 0.001, Cohen's d = 0.44) and reported more childhood trauma experiences than HC (X² = 289.0, p < .001) than HC. Patients with at least one moderate to severe trauma had poorer social functioning than patients without childhood trauma (F = 8.16, p = .004, Cohen's d = 0.17). Within the patients, a cumulative relationship was observed in that more severe childhood trauma was associated with lower social functioning (F = 2.65, p = .02, Cohen's d = 0.20). No significant associations were observed for having at least one moderate to severe trauma or cumulative traumas on social functioning in the HC. Follow-up analysis showed that patients in remission childhood trauma also had poorer social functioning.

CONCLUSION

Patients who reported childhood trauma experiences had poorer social functioning both during an active illness phase and in remission.

Volumetric differences in hippocampal subfields and associations with clinical measures in myalgic encephalomyelitis/chronic fatigue syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients suffer from a cognitive and memory dysfunction. Because the hippocampus plays a key role in both cognition and memory, we tested for volumetric differences in the subfields of the hippocampus in ME/CFS. We estimated hippocampal subfield volumes for 25 ME/CFS patients who met Fukuda criteria only (ME/CFS_Fukuda), 18 ME/CFS patients who met the stricter ICC criteria (ME/CFS_ICC), and 25 healthy controls (HC). Group comparisons with HC detected extensive differences in subfield volumes in ME/CFS_ICC but not in ME/CFS_Fukuda. ME/CFS_ICC patients had significantly larger volume in the left subiculum head (p < 0.001), left presubiculum head (p = 0.0020), and left fimbria (p = 0.004). Correlations of hippocampus subfield volumes with clinical measures were stronger in ME/CFS_ICC than in ME/CFS_Fukuda patients. In ME/CFS_Fukuda patients, we detected positive correlations between fatigue and hippocampus subfield volumes and a negative correlation between sleep disturbance score and the right CA1 body volume. In ME/CFS_ICC patients, we detected a strong negative relationship between fatigue and left hippocampus tail volume. Strong negative relationships were also detected between pain and SF36 physical scores and two hippocampal subfield volumes (left: GC‐ML‐DG head and CA4 head). Our study demonstrated that volumetric differences in hippocampal subfields have strong statistical inference for patients meeting the ME/CFS_ICC case definition and confirms hippocampal involvement in the cognitive and memory problems of ME/CFS_ICC patients.

Childhood adversities and bipolar disorder: a neuroimaging focus

Early-life adverse events or childhood adversities (CAs) are stressors and harmful experiences severely impacting on a child's wellbeing and development. Examples of CAs include parental neglect, emotional and physical abuse and bullying. Even though the prevalence of CAs and their psychological effects in both healthy and psychiatric populations is established, only a paucity of studies have investigated the neurobiological firms associated with CAs in bipolar disorder (BD). In particular, the exact neural mechanisms and trajectories of biopsychosocial models integrating both environmental and genetic effects are still debated. Considering the potential impact of CAs on BD, including its clinical manifestations, we reviewed existing literature discussing the association between CAs and brain alterations in BD patients. Results showed that CAs are associated with volume alterations of several grey matter regions including the hippocampus, thalamus, amygdala and frontal cortex. A handful of studies suggest the presence of alterations in the corpus callosum and the pre-fronto-limbic connectivity at rest. Alterations in these regions of the brain of patients with BD are possibly due to the effect of stress produced by CAs, being hippocampus part of the hypothalamus-pituitary-adrenal axis and thalamus together with amygdala filtering sensory information and regulating emotional responses. However, results are mixed possibly due to the heterogeneity of methods and study design. Future neuroimaging studies disentangling between different types of CAs or differentiating between BD sub-types are needed in order to understand the link between CAs and BD.

The Relationship Among BDNF Val66Met Polymorphism, Plasma BDNF Level, and Trait Anxiety in Chinese Patients With Panic Disorder

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a candidate for susceptibility locus of Panic disorder (PD). However, the findings about the role of the BDNF Val66Met variant in PD were not consistent. Till now, the relationship between BDNF Val66Met polymorphism and anxiety-related traits in PD patients has been rarely explored. This study aimed to explore the relationship among BDNF Val66Met polymorphism, plasma BDNF level and anxiety-related trait in Chinese PD patients.

METHOD

This multi-center study included 116 PD patients and 99 health controls. We detected single-nucleotide polymorphism (SNP) of BDNF rs6265 (Val66Met) and BDNF plasma level in the two groups. In addition, PD patients were administered the State-Trait Anxiety Inventory (STAI), Panic Disorder Severity Scale-Chinese Version (PDSS-CV) and Hamilton Anxiety Rating Scale (HAMA-14). Quantitative comparison of the differences of BDNF concentration among subjects with different genotypes and association between BDNF Val66Met genotype and trait anxiety were performed.

RESULTS

There were no significant differences in the genotype frequency (p = 0.79) or allele frequency (p = 0.88) between PD patients and health controls. BDNF plasma levels of PD patients were significantly lower than those in control group (p = 0.003). BDNF plasma levels of the Met/Met genotype were significantly lower than those of Val/Met genotype in PD patients (p = 0.033). PD patients carried Met/Met genotype showed significantly higher scores in STAI trait compared to those carried Val/Val genotype (p = 0.045) and Val/Met genotype (p = 0.018). STAI trait scores of PD patients with agoraphobia were significantly higher than those of patients without agoraphobia (p < 0.05). The ANCOVA showed that the dependent variable STAI trait score was significantly affected by factor "genotype" (Val/Val, Val/Met, Met/Met, p = 0.029), and covariate "agoraphobia" (p = 0.008). In this model, 11.5% of the variance of the STAI trait score was explained by the BDNF genotype. Contrast analysis showed STAI trait scores of Met/Met subjects were significantly higher than those of Val/Met (p = 0.018) and Val/Val individuals (p = 0.045).

CONCLUSION

We found that anxiety trait was associated with the BDNF polymorphism in PD patients. BDNF Met/Met genotype may decrease plasma BDNF level and increase trait anxiety in panic disorder.

Exploring the association between brain-derived neurotrophic factor levels and longitudinal psychopathological and cognitive changes in Sardinian psychotic patients

Background and hypothesis

Schizophrenia spectrum disorders are among the most debilitating mental disorders and has complex pathophysiological underpinnings. There is growing evidence that brain-derived neurotrophic factor (BDNF) can play a role in its pathogenesis. The present study investigated the longitudinal variation of serum BDNF levels in a 24-month observational prospective cohort study of Sardinian psychotic patients and its relationship with psychopathological and cognitive changes. Furthermore, we examined whether genetic variation within the BDNF gene could moderate these relationships.

Study design

Every 6 months, 105 patients were assessed for their BDNF serum levels, as well as for a series of psychopathological, cognitive, and social measures. We performed a targeted analysis of four tag single nucleotide polymorphisms within the BDNF gene that were selected and analyzed using polymerase chain reaction. Longitudinal data were analyzed using mixed-effects linear regression models.

Study results

We observed a declining longitudinal trajectory of BDNF levels in psychotic patients in general, and in relation to the severity of depressive and negative symptoms. BDNF serum levels also declined in patients scoring lower in cognitive measures such as attention and speed of information processing and verbal fluency. The rs7934165 polymorphism moderated the significant association between verbal fluency and BDNF levels.

Conclusions

These findings in patients from real-world settings suggest a plausible role of peripheral BDNF levels as a marker of illness burden in schizophrenia spectrum disorders.

Molecular impacts of childhood abuse on the human brain

Childhood abuse (CA) is a prevalent global health concern, increasing the risk of negative mental health outcomes later in life. In the literature, CA is commonly defined as physical, sexual, and emotional abuse, as well as neglect. Several mental disorders have been associated with CA, including depression, bipolar disorder, schizophrenia, and post-traumatic stress disorder, along with an increased risk of suicide. It is thought that traumatic life events occurring during childhood and adolescence may have a significant impact on essential brain functions, which may persist throughout adulthood. The interaction between the brain and the external environment can be mediated by epigenetic alterations in gene expression, and there is a growing body of evidence to show that such changes occur as a function of CA. Disruptions in the HPA axis, myelination, plasticity, and signaling have been identified in individuals with a history of CA. Understanding the molecular impact of CA on the brain is essential for the development of treatment and prevention measures. In this review, we will summarize studies that highlight the molecular changes associated with CA in the human brain, along with supporting evidence from peripheral studies and animal models. We will also discuss some of the limitations surrounding the study of CA and propose extracellular vesicles as a promising future approach in the field.

Genetic contributions to bipolar disorder: current status and future directions

Bipolar disorder (BD) is a highly heritable mental disorder and is estimated to affect about 50 million people worldwide. Our understanding of the genetic etiology of BD has greatly increased in recent years with advances in technology and methodology as well as the adoption of international consortiums and large population-based biobanks. It is clear that BD is also highly heterogeneous and polygenic and shows substantial genetic overlap with other psychiatric disorders. Genetic studies of BD suggest that the number of associated loci is expected to substantially increase in larger future studies and with it, improved genetic prediction of the disorder. Still, a number of challenges remain to fully characterize the genetic architecture of BD. First among these is the need to incorporate ancestrally-diverse samples to move research away from a Eurocentric bias that has the potential to exacerbate health disparities already seen in BD. Furthermore, incorporation of population biobanks, registry data, and electronic health records will be required to increase the sample size necessary for continued genetic discovery, while increased deep phenotyping is necessary to elucidate subtypes within BD. Lastly, the role of rare variation in BD remains to be determined. Meeting these challenges will enable improved identification of causal variants for the disorder and also allow for equitable future clinical applications of both genetic risk prediction and therapeutic interventions.

A Meta-Analysis of Brain-Derived Neurotrophic Factor Effects on Brain Volume in Schizophrenia: Genotype and Serum Levels

AIM

The Val66Met single-nucleotide polymorphism (SNP) on the BDNF gene has established pleiotropic effects on schizophrenia incidence and morphologic alterations in the illness. The effects of brain-derived neurotrophic factor (BDNF) on brain volume measurements are however mixed seeming to be less established for most brain regions. The current meta-analytic review examined (1) the association of the Val66Met SNP and brain volume alterations in schizophrenia by comparing Met allele carriers to Val/Val homozygotes and (2) the association of serum BDNF with brain volume measurements.

METHOD

Studies included in the meta-analyses were identified through an electronic search of PubMed and PsycInfo (via EBSCO) for English language publications from January 2000 through December 2017. Included studies had conducted a genotyping procedure of Val66Met or obtained assays of serum BDNF and obtained brain volume data in patients with psychotic disorders. Nonhuman studies were excluded.

RESULTS

Study 1 which included 52 comparisons of Met carriers and Val/Val homozygotes found evidence of lower right and left hippocampal volumes among Met allele carriers with schizophrenia. Frontal measurements, while also lower among Met carriers, did not achieve statistical significance. Study 2 which included 7 examinations of the correlation between serum BDNF and brain volume found significant associations between serum BDNF levels and right and left hippocampal volume with lower BDNF corresponding to lower volumes.

DISCUSSION

The meta-analyses provided evidence of associations between brain volume alterations in schizophrenia and variations on the Val66Met SNP and serum BDNF. Given the limited number of studies, it remains unclear if BDNF effects are global or regionally specific.

Residential green space structures are associated with a lower risk of bipolar disorder: A nationwide population-based study in Taiwan

Although many researchers have identified the potential psychological benefits offered by greenness, the association between green space structures and mental disorders is not well understood. The purpose of this study was to identify associations between green space structures and the incidence of bipolar disorder. To this end, we investigated 1,907,776 individuals collected from Taiwan's National Health Insurance Research Database. After a follow-up investigation from 2005 to 2016, among those with no history of bipolar disorder, 20,548 individuals were further found to be diagnosed with bipolar disorder. A geographic information system and landscape index were used to quantify three indices of green space structures: mean patch area (area and edge), mean fractal dimension index (shape), and mean proximity index (proximity). Additionally, greenness indices, the normalized difference vegetation index, and the enhanced vegetation index were used to confirm the association between greenness and incidence of bipolar disorder. These five indices were used to represent the individual's exposure according to the township of the hospital that they most frequently visited with symptoms of the common cold. Spearman's correlation analysis was performed to select variables by considering their collinearity. Subsequently, the frailty model for each index was used to examine the specific associations between those respective indices and the incidence of bipolar disorder by adjusting for related risk factors, such as socioeconomic status, metabolic syndrome, and air pollution. A negative association was identified between the mean patch area and the mean proximity index, and the incidence of bipolar disorder. In contrast, a positive association was found between the mean fractal dimension index and the incidence of bipolar disorder. We observed similar results in sensitivity testing and subgroup analysis. Exposure to green spaces with a larger area, greater proximity, lower complexity, and greener area may reduce the risk of bipolar disorder.

Early-life trauma endophenotypes and brain circuit-gene expression relationships in functional neurological (conversion) disorder

Functional neurological (conversion) disorder (FND) is a neuropsychiatric condition whereby individuals present with sensorimotor symptoms incompatible with other neurological disorders. Early-life maltreatment (ELM) is a risk factor for developing FND, yet few studies have investigated brain network-trauma relationships in this population. In this neuroimaging-gene expression study, we used two graph theory approaches to elucidate ELM subtype effects on resting-state functional connectivity architecture in 30 patients with motor FND. Twenty-one individuals with comparable depression, anxiety, and ELM scores were used as psychiatric controls. Thereafter, we compared trauma endophenotypes in FND with regional differences in transcriptional gene expression as measured by the Allen Human Brain Atlas (AHBA). In FND patients only, we found that early-life physical abuse severity, and to a lesser extent physical neglect, correlated with corticolimbic weighted-degree functional connectivity. Connectivity profiles influenced by physical abuse occurred in limbic (amygdalar-hippocampal), paralimbic (cingulo-insular and ventromedial prefrontal), and cognitive control (ventrolateral prefrontal) areas, as well as in sensorimotor and visual cortices. These findings held adjusting for individual differences in depression/anxiety, PTSD, and motor phenotypes. In FND, physical abuse also correlated with amygdala and insula coupling to motor cortices. In exploratory analyses, physical abuse correlated connectivity maps overlapped with the AHBA spatial expression of three gene clusters: (i) neuronal morphogenesis and synaptic transmission genes in limbic/paralimbic areas; (ii) locomotory behavior and neuronal generation genes in left-lateralized structures; and (iii) nervous system development and cell motility genes in right-lateralized structures. These circuit-specific architectural profiles related to individual differences in childhood physical abuse burden advance our understanding of the pathophysiology of FND.

Evaluation on Long-Term Test-Retest Reliability of the Short-Form Childhood Trauma Questionnaire in Patients with Schizophrenia

Background

Many studies have reported an association between childhood trauma exposure and schizophrenia. Among these studies, the Short-form Childhood Trauma Questionnaire (CTQ-SF) is one of the most widely used measures of childhood trauma. However, little is known regarding the long-term reliability of the CTQ-SF, especially in patients with psychopathology.

Methods

The CTQ-SF was administered to 50 patients diagnosed with schizophrenia from a hospital in Changsha, Hunan, China. These patients were asked to re-complete the CTQ-SF when they were re-hospitalized or received outpatient treatments in the same hospital within 4 years of follow-up. Intraclass correlation coefficient (ICC) was used to assess test–retest reliability of the CTQ-SF over the intervals. Associations of the CTQ-SF with the Positive and Negative Syndrome Scale (PANSS) and Wechsler Adult Intelligence Scale (WAIS) were tested using Spearman correlation coefficients.

Results

Among the participants, 35 (70.0%) patients re-completed the CTQ-SF after an interval averaging 11.26 months. Excellent test–retest reliabilities (with ICC > 0.75) were found for the total CTQ-SF score (ICC = 0.772) as well as scores of the emotional abuse (ICC = 0.808), physical abuse (ICC = 0.756), sexual abuse (ICC = 0.877) and physical neglect (ICC = 0.751) subscales. Meanwhile, a moderate test–retest reliability was found for the emotional neglect subscale (ICC = 0.538). At both baseline and follow-up, no significant correlations (p > 0.05) were found between CTQ-SF scores and any other clinical assessments.

Conclusion

Our results suggest that CTQ-SF is reliable to assess childhood trauma exposures in schizophrenia over relatively long intervals, regardless of patients’ current symptoms and states of cognition.

Environmental Risk Factors for Schizophrenia and Bipolar Disorder and Their Relationship to Genetic Risk: Current Knowledge and Future Directions

Schizophrenia (SZ) and bipolar disorder (BD) are severe psychiatric disorders which result from complex interplay between genetic and environmental factors. It is well-established that they are highly heritable disorders, and considerable progress has been made identifying their shared and distinct genetic risk factors. However, the 15-40% of risk that is derived from environmental sources is less definitively known. Environmental factors that have been repeatedly investigated and often associated with SZ include: obstetric complications, infections, winter or spring birth, migration, urban living, childhood adversity, and cannabis use. There is evidence that childhood adversity and some types of infections are also associated with BD. Evidence for other risk factors in BD is weaker due to fewer studies and often smaller sample sizes. Relatively few environmental exposures have ever been examined for SZ or BD, and additional ones likely remain to be discovered. A complete picture of how genetic and environmental risk factors confer risk for these disorders requires an understanding of how they interact. Early gene-by-environment interaction studies for both SZ and BD often involved candidate genes and were underpowered. Larger samples with genome-wide data and polygenic risk scores now offer enhanced prospects to reveal genetic interactions with environmental exposures that contribute to risk for these disorders. Overall, although some environmental risk factors have been identified for SZ, few have been for BD, and the extent to which these account for the total risk from environmental sources remains unknown. For both disorders, interactions between genetic and environmental risk factors are also not well understood and merit further investigation. Questions remain regarding the mechanisms by which risk factors exert their effects, and the ways in which environmental factors differ by sex. Concurrent investigations of environmental and genetic risk factors in SZ and BD are needed as we work toward a more comprehensive understanding of the ways in which these disorders arise.

Bipolar disorder: Trimodal age-at-onset distribution

OBJECTIVE

Bipolar disorder (BD) is a chronic mental health disorder with significant morbidity and mortality. Age at onset (AAO) may be a key variable in delineating more homogeneous subgroups of BD patients. However, no known research has systematically assessed how BD age-at-onset subgroups should be defined.

METHODS

We systematically searched the following databases: Cochrane Central Register of Controlled Trials, PsycINFO, MEDLINE, Embase, CINAHL, Scopus, Proquest Dissertations and Theses, Google Scholar and BIOSIS Previews. Original quantitative English language studies investigating AAO in BD were sought.

RESULTS

A total of 9454 unique publications were identified. Twenty-one of these were included in data analysis (n = 22981 BD participants). Fourteen of these studies (67%, n = 13626 participants) found a trimodal AAO distribution: early-onset (µ = 17.3, σ = 1.19, 45% of sample), mid-onset (µ = 26.0, σ = 1.72, 35%), and late-onset (µ = 41.9, σ = 6.16, 20%). Five studies (24%, n = 1422 participants) described a bimodal AAO distribution: early-onset (µ = 24.3, σ = 6.57, 66% of sample) and late-onset (µ = 46.3, σ = 14.15, 34%). Two studies investigated cohort effects on BD AAO and found that when the sample was not split by cohort, a trimodal AAO was the winning model, but when separated by cohort a bimodal distribution fit the data better.

CONCLUSIONS

We propose that the field conceptualises bipolar disorder age-at-onset subgroups as referring broadly to life stages. Demarcating BD AAO groups can inform treatment and provide a framework for future research to continue to investigate potential mechanisms of disease onset.

Genetic Influences on Hippocampal Subfields: An Emerging Area of Neuroscience Research

There is clear evidence that hippocampal subfield volumes have partly distinct genetic determinants associated with specific biological processes. The identification of genetic correlates of hippocampal subfield volumes may help to elucidate the mechanisms of neurologic diseases, as well as aging and neurodegenerative processes. However, despite the emerging interest in this area of research, the current knowledge of the genetic architecture of hippocampal subfields has not yet been consolidated. We aimed to provide a review of the current evidence from genetic studies of hippocampal subfields, highlighting current priorities and upcoming challenges. The limited number of studies investigating the influential genetic effects on hippocampal subfields, a lack of replicated results and longitudinal designs, and modest sample sizes combined with insufficient standardization of protocols are identified as the most pressing challenges in this emerging area of research.

Systemic inflammation and grey matter volume in schizophrenia and bipolar disorder: Moderation by childhood trauma severity

BACKGROUND

Elevated levels of systemic inflammation are consistently reported in both schizophrenia (SZ) and bipolar-I disorder (BD), and are associated with childhood trauma exposure. We tested whether childhood trauma exposure moderates associations between systemic inflammation and brain morphology in people with these diagnoses.

METHODS

Participants were 55 SZ cases, 52 BD cases and 59 healthy controls (HC) who underwent magnetic resonance imaging. Systemic inflammation was measured using a composite z-score derived from serum concentrations of interleukin 6, tumor necrosis factor alpha and C-reactive protein. Indices of grey matter volume covariation (GMC) were derived from independent component analysis. Childhood trauma was measured using the Childhood Trauma Questionnaire (CTQ Total score).

RESULTS

A series of moderated moderation analyses indicated that increased systemic inflammation were associated with increased GMC in the striatum and cerebellum among all participants. Severity of childhood trauma exposure moderated the relationship between systemic inflammation and GMC in one component, differently among the groups. Specifically, decreased GMC in the PCC/precuneus, parietal lobule and postcentral gyrus, and increased GMC in the left middle temporal gyrus was associated with increased systemic inflammation in HC individuals exposed to high (but not low or average) levels of trauma and in SZ cases exposed to low (but not average or high) levels of trauma, but not in BD cases.

CONCLUSIONS

Increased systemic inflammation is associated with grey matter changes in people with psychosis, and these relationships may be partially and differentially moderated by childhood trauma exposure according to diagnosis.

Exploring the Interplay Between Adversity, Neurocognition, Social Cognition, and Functional Outcome in People With Psychosis: A Narrative Review

History of adversity is associated with subsequent psychosis, and with a spectrum of cognitive alterations in individuals with psychosis. These cognitive features go from neurocognitive aspects as working memory and attention, to complex social cognitive processes as theory of mind and emotional perception. Difficulties in these domains impact patients' social and occupational functioning, which has been shown to be more impaired in those previously exposed to childhood trauma. However, the interplay between adversity, neurocognition, and functioning is yet poorly understood. This narrative review aims to explore the evidence on whether deficits in neurocognitive and social cognitive domains may act as possible putative mechanism linking adversity with functioning in people with psychosis. We show available evidence supporting the link between adversity and poorer functioning in psychosis, especially in chronic stages; and replicated evidence suggesting associations of social cognition and, to a lesser extent, neurocognition with impairment in functioning in patients; although there is still an important gap in the literature testing particularly deficits in social cognition as mediator of the link between adversity and functional decline in psychosis. Targeting interventions focusing on neurocognition and social cognition in individuals with adversity and psychosis seems important, given the severe deterioration of these patients in these domains, although more research is needed to test whether such treatments can specifically improve functioning in individuals with psychosis and adversity. Literature aiming to understand the determinants of functional outcome should consider the pervasive impact of childhood adversity, and its related effects on cognition.

Associations Between Childhood Trauma and the Age of First-Time Drug Use in Methamphetamine-Dependent Patients

Childhood trauma is related to substance use disorder; however, few studies have examined the relationship between childhood trauma and the age at which the drug was first used. The aim of this study was to investigate the relationship between childhood trauma and the age of first-time drug use among methamphetamine-dependent patients. Moreover, we analyzed the characteristics of adverse family environment associated with severe childhood trauma and the risk factors for starting drugs in minors. A baseline interview was conducted with 110 participants who were in detoxification, including demographic information, past substance use, and age of first-time drug use. The participants' childhood trauma experience before 18 years of age was evaluated using the simplified version of the Childhood Trauma Questionnaire (CTQ-SF). The Chinese version of the Family Environment Scale (FES-CV) was used to assess the family environment of methamphetamine-dependent patients. Among 110 non-injecting methamphetamine-dependent patients, nearly half (n = 48, 43.6%) had moderate and severe childhood trauma. Correlation analysis showed that the age of first-time drug use negatively correlated with emotional abuse (r = -0.32, p < 0.01) and physical abuse (r = -0.27, p < 0.01). The age of first-time drug use negatively correlated with conflict (r = -0.20, p < 0.05) and independence (r = -0.22, p < 0.05) of family environment, but positively correlated with intellectual-cultural orientation (r = 0.28, p < 0.01). Additionally, childhood trauma factors significantly correlated with many indexes of family environment, especially cohesion (r = -0.45, p < 0.01), conflict (r = 0.49, p < 0.01), and independence (r = 0.33, p < 0.01). Additionally, the regression model showed that when emotional abuse increased by one point, the age of first-time drug use was 0.69 years earlier. These findings suggest that a detrimental family environment can aggravate childhood trauma, and the experience of childhood emotional or physical abuse may be an effective predictor of early drug use among methamphetamine-dependent patients.

Childhood Maltreatment in Bipolar Disorders

In this chapter, we will focus on childhood maltreatment and its role in the vulnerability to BD.We will review how childhood maltreatment and trauma not only predispose to the development of BD but also to a more unstable, pernicious, and severe clinical expression of the disorder. This environmental risk factor is suggested to be part of a multiple hit model of vulnerability, involving not only early stressors (prenatal and postnatal ones) but also interactions with the genetic background of individuals and with other stressors occurring later in life. We will also review how childhood maltreatment and trauma may modify the brain functioning and circuits and alter some biological pathways in BD, hence leading to psychopathology. Finally, we will briefly discuss the implications for clinical practice and treatment.

FreeSurfer ‐based segmentation of hippocampal subfields: A review of methods and applications, with a novel quality control procedure for ENIGMA studies and other collaborative efforts

Structural hippocampal abnormalities are common in many neurological and psychiatric disorders, and variation in hippocampal measures is related to cognitive performance and other complex phenotypes such as stress sensitivity. Hippocampal subregions are increasingly studied, as automated algorithms have become available for mapping and volume quantification. In the context of the Enhancing Neuro Imaging Genetics through Meta Analysis Consortium, several Disease Working Groups are using the FreeSurfer software to analyze hippocampal subregion (subfield) volumes in patients with neurological and psychiatric conditions along with data from matched controls. In this overview, we explain the algorithm's principles, summarize measurement reliability studies, and demonstrate two additional aspects (subfield autocorrelation and volume/reliability correlation) with illustrative data. We then explain the rationale for a standardized hippocampal subfield segmentation quality control (QC) procedure for improved pipeline harmonization. To guide researchers to make optimal use of the algorithm, we discuss how global size and age effects can be modeled, how QC steps can be incorporated and how subfields may be aggregated into composite volumes. This discussion is based on a synopsis of 162 published neuroimaging studies (01/2013–12/2019) that applied the FreeSurfer hippocampal subfield segmentation in a broad range of domains including cognition and healthy aging, brain development and neurodegeneration, affective disorders, psychosis, stress regulation, neurotoxicity, epilepsy, inflammatory disease, childhood adversity and posttraumatic stress disorder, and candidate and whole genome (epi‐)genetics. Finally, we highlight points where FreeSurfer‐based hippocampal subfield studies may be optimized.

Associations between brain-derived neurotrophic factor and cognitive impairment in panic disorder

INTRODUCTION

Our study was designed to examine the relationship between Brain-Derived Neurotrophic Factor (BDNF) genotypes (rs6265, Val66Met), BDNF plasma levels, and cognitive impairment in Chinese patients with panic disorder (PD).

METHODS

Total 85 patients with PD and 91 healthy controls finally completed all assessments. The severity of panic symptoms and whole anxiety of PD was measured by Panic Disorder Severity Scale-Chinese Version (PDSS-CV) and Hamilton Anxiety Scale (HAMA-14). Montreal Cognitive Assessment (MoCA) and some neurocognitive measures were conducted to evaluate the cognitive performance. All participants were detected for the plasma BDNF levels and BDNF Val66Met polymorphism before assessment and treatment.

RESULTS

No significant differences were found in the BDNF allele frequencies and the BDNF genotype distributions between healthy controls and PD patients. BDNF Met/Met genotype was associated with lower BDNF plasma levels in PD patients, and PD patients with BDNF Met/Met genotype had the lower scores in the attention and speed of processing domains compared to those with Val/Val and Met/Val genotype (p's < .05). Among PD patients, the BDNF plasma levels showed moderate positive correlations with Stroop interference (r = .60, p < .001). Using the MoCA data, the BDNF plasma levels were correlated with delayed memory (r = .50, p < .001), verbal learning (r = .45, p < .001), and total scores of MoCA (r = .51, p < .001).

CONCLUSIONS

The BDNF Met/Met genotype may be associated with lower BDNF plasma levels and cognitive impairments in PD patients.

In vivo hippocampal subfield volumes in bipolar disorder—A mega‐analysis from The Enhancing Neuro Imaging Genetics through Meta‐Analysis Bipolar Disorder Working Group

The hippocampus consists of anatomically and functionally distinct subfields that may be differentially involved in the pathophysiology of bipolar disorder (BD). Here we, the Enhancing NeuroImaging Genetics through Meta‐Analysis Bipolar Disorder workinggroup, study hippocampal subfield volumetry in BD. T1‐weighted magnetic resonance imaging scans from 4,698 individuals (BD = 1,472, healthy controls [HC] = 3,226) from 23 sites worldwide were processed with FreeSurfer. We used linear mixed‐effects models and mega‐analysis to investigate differences in hippocampal subfield volumes between BD and HC, followed by analyses of clinical characteristics and medication use. BD showed significantly smaller volumes of the whole hippocampus (Cohen's d = −0.20), cornu ammonis (CA)1 (d = −0.18), CA2/3 (d = −0.11), CA4 (d = −0.19), molecular layer (d = −0.21), granule cell layer of dentate gyrus (d = −0.21), hippocampal tail (d = −0.10), subiculum (d = −0.15), presubiculum (d = −0.18), and hippocampal amygdala transition area (d = −0.17) compared to HC. Lithium users did not show volume differences compared to HC, while non‐users did. Antipsychotics or antiepileptic use was associated with smaller volumes. In this largest study of hippocampal subfields in BD to date, we show widespread reductions in nine of 12 subfields studied. The associations were modulated by medication use and specifically the lack of differences between lithium users and HC supports a possible protective role of lithium in BD.

A systematic review on mediators between adversity and psychosis: potential targets for treatment

Various psychological and biological pathways have been proposed as mediators between childhood adversity (CA) and psychosis. A systematic review of the evidence in this domain is needed. Our aim is to systematically review the evidence on psychological and biological mediators between CA and psychosis across the psychosis spectrum. This review followed PRISMA guidelines. Articles published between 1979 and July 2019 were identified through a literature search in OVID (PsychINFO, Medline and Embase) and Cochrane Libraries. The evidence by each analysis and each study is presented by group of mediator categories found. The percentage of total effect mediated was calculated. Forty-eight studies were included, 21 in clinical samples and 27 in the general population (GP) with a total of 82 352 subjects from GP and 3189 from clinical studies. The quality of studies was judged as 'fair'. Our results showed (i) solid evidence of mediation between CA and psychosis by negative cognitive schemas about the self, the world and others (NS); by dissociation and other post-traumatic stress disorder symptoms; and through an affective pathway in GP but not in subjects with disorder; (iii) lack of studies exploring biological mediators. We found evidence suggesting that various overlapping and not competing pathways involving post-traumatic and mood symptoms, as well as negative cognitions contribute partially to the link between CA and psychosis. Experiences of CA, along with relevant mediators should be routinely assessed in patients with psychosis. Evidence testing efficacy of interventions targeting such mediators through cognitive behavioural approaches and/or pharmacological means is needed in future.

Effect of BDNF Val66Met on hippocampal subfields volumes and compensatory interaction with APOE-ε4 in middle-age cognitively unimpaired individuals from the ALFA study

Background

Current evidence supports the involvement of brain-derived neurotrophic factor (BDNF) Val66Met polymorphism, and the ε4 allele of APOE gene in hippocampal-dependent functions. Previous studies on the association of Val66Met with whole hippocampal volume included patients of a variety of disorders. However, it remains to be elucidated whether there is an impact of BDNF Val66Met polymorphism on the volumes of the hippocampal subfield volumes (HSv) in cognitively unimpaired (CU) individuals, and the interactive effect with the APOE-ε4 status.

Methods

BDNF Val66Met and APOE genotypes were determined in a sample of 430 CU late/middle-aged participants from the ALFA study (ALzheimer and FAmilies). Participants underwent a brain 3D-T1-weighted MRI scan, and volumes of the HSv were determined using Freesurfer (v6.0). The effects of the BDNF Val66Met genotype on the HSv were assessed using general linear models corrected by age, gender, education, number of APOE-ε4 alleles and total intracranial volume. We also investigated whether the association between APOE-ε4 allele and HSv were modified by BDNF Val66Met genotypes.

Results

BDNF Val66Met carriers showed larger bilateral volumes of the subiculum subfield. In addition, HSv reductions associated with APOE-ε4 allele were significantly moderated by BDNF Val66Met status. BDNF Met carriers who were also APOE-ε4 homozygous showed patterns of higher HSv than BDNF Val carriers.

Conclusion

To our knowledge, the present study is the first to show that carrying the BDNF Val66Met polymorphisms partially compensates the decreased on HSv associated with APOE-ε4 in middle-age cognitively unimpaired individuals.

Electronic supplementary material

The online version of this article (10.1007/s00429-020-02125-3) contains supplementary material, which is available to authorized users.

Childhood trauma, psychiatric disorders, and criminality in women: Associations with serum levels of brain-derived neurotrophic factor

Psychiatric disorders and childhood trauma are highly prevalent in female inmates. Brain-derived neurotrophic factor (BDNF) plays a number of roles in neuronal survival, structure, and function. Data in the literature suggest that it is a neurobiological substrate that moderates the impact of childhood adversities on the late expression of psychiatric disorders. The aim of this study was to determine whether five childhood trauma subtypes-physical abuse, sexual abuse, emotional abuse, physical neglect, and emotional neglect-are associated with adult psychiatric disorders, BDNF levels, and criminality among incarcerated women. This was a cross-sectional study involving a consecutive sample of 110 women, divided into three groups of women (forensic - mentally ill who committed crimes, clinical psychiatric inpatients and healthy controls). The Childhood Trauma Questionnaire and the Mini-International Neuropsychiatric Interview-Plus were applied in the whole sample, and BDNF levels were measured in a sub-sample of 54 women. The rates of mental illness and childhood trauma were high in the forensic group. Emotional abuse was higher in the clinical and forensic groups than in the healthy control group. Lower BDNF levels were associated with emotional abuse in the forensic group as well as with sexual abuse in the healthy control group. After multinomial logistic regression, lower levels of BDNF, higher levels of emotional abuse and the presence of familial offense were considered factors related to clinical psychiatric group. The results of this study underscore the idea that BDNF may be an important factor related to the development of diseases and criminality in women who are victims of childhood trauma, becoming a possible biological marker.

Childhood maltreatment and polygenic risk in bipolar disorders

BACKGROUND

Childhood maltreatment is a well-known risk factor for developing a more severe and complex form of bipolar disorders (BD). However, knowledge is scarce about the interactions between childhood maltreatment and underlying genetic vulnerability on the clinical expression of BD.

METHOD

We assigned a BD-polygenic risk score (BD-PRS), calculated from the Psychiatric Genomics Consortium, to each individual in a sample of 402 cases with BD. The lifetime clinical expression of BD was characterized using structured interviews and patients completed the Childhood Trauma Questionnaire (CTQ) to assess the severity of childhood maltreatment.

RESULTS

Cases who reported more severe childhood maltreatment had a lower BD-PRS (rho = -0.12, P = .01), especially when considering emotional abuse (rho = -0.16, P = .001). An interaction between BD-PRS and childhood maltreatment was observed for the risk of rapid cycling (P = .01). No further interactions between BD-PRS and childhood maltreatment were observed for other clinical characteristics (age at onset, suicide attempts, number of mood episodes, mixed features, substance use disorders and psychotic symptoms).

CONCLUSION

Our study is the first to show that less genetic risk may be needed to develop a more unstable form of BD when exposed to childhood maltreatment. Our study supports childhood trauma as an independent risk factor for BD.

Elevated hair cortisol is associated with childhood maltreatment and cognitive impairment in schizophrenia and in bipolar disorders

BACKGROUND

The neural diathesis-stress model is useful to understand schizophrenia (SZ) and bipolar (BD) disorders. Childhood maltreatment could affect the Hypothalamic-Pituitary-Adrenal (HPA)-axis and lead to chronic changes in stress-sensitivity, which can be measured with hair cortisol concentrations (HCC), representing long-term, cumulative cortisol levels. Here we investigated if childhood trauma experiences are associated with chronic changes in the HPA axis in severe mental disorders.

METHODS

Participants with SZ or BD (N = 63) and healthy controls (N = 94) were included, and HCC was measured by ELISA. History of childhood maltreatment was assessed using the Childhood Trauma Questionnaire (CTQ). Global function and symptom levels were obtained using the Global Assessment of Functioning (GAF) Scale and the Positive and Negative Syndrome Scale (PANSS). A neuropsychological test battery (MATRICS) was performed to assess cognitive functions.

RESULTS

Our study shows for the first time that patients with a history of childhood maltreatment have higher HCC relative to both healthy controls and patients without a history of childhood maltreatment (P = 0.01, ƞp² = 0.046). In addition, patients experiencing a mood episode had higher HCC than patients in remission (P = 0.03). Lastly, we are the first to show that patients with higher HCC had poorer cognitive performance, specifically working memory (P = 0.01). All associations were irrespective of diagnostic group. A factor analysis confirmed a subgroup within the patients characterized by childhood maltreatment and elevated HCC.

CONCLUSIONS

Findings support the neural diathesis-stress model in SZ and BD pointing to long-term changes in HPA-axis following childhood maltreatment experiences.

Hair cortisol concentrations as an indicator of potential HPA axis hyperactivation in risk for psychosis

A chronic hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis is assumed to be an important indicator of vulnerability for psychosis. Despite the considerable research on this topic, putative social origins of HPA axis hyperactivation have received little attention in the literature so far. Also, the inconsistency of previous findings calls for new and reliable methods in the assessment of HPA axis activation. To address these issues, we used hair cortisol concentrations as an indicator of chronic HPA axis activation in participants at elevated risk for psychosis (clinical risk: n = 43, familial risk: n = 32) and low-risk controls (n = 35), and assessed its relation with a variety of social stressors. We also tested the interaction effect between social stressors and familial risk status on hair cortisol concentrations (moderation analysis). Participants at elevated risk for psychosis did not show significantly higher hair cortisol concentrations than low-risk controls. However, severe social stressors (child abuse experiences, traumatic events) predicted hair cortisol concentrations in the total sample. This relationship was not significantly moderated by familial risk status (as a marker of genetic risk). The results challenge the assumption that HPA axis hyperactivation is an early vulnerability indicator for psychosis but leave the possibility that it manifests only at more severe risk stages. Furthermore, the findings suggest that acquired experiences contribute to the emergence of HPA axis hyperactivation, which might occur via a gene-environment correlation rather than via a gene-environment interaction.

The relationship between physical activity, clinical and cognitive characteristics and BDNF mRNA levels in patients with severe mental disorders

Background: Here we aimed to clarify the association of physical activity with cognitive function and current mood in severe mental disorders in the most extensive sample to date. Secondly, we aimed to investigate the relationship between physical activity and BDNF mRNA levels.Methods: Three hundred and six patients with a DSM-IV schizophrenia (SZ) or bipolar disorder (BD) spectrum diagnosis were included. Clinical characteristics were assessed using the Structured Clinical Interview for DSM-IV. Depressive symptomatology was measured using the Inventory of Depressive Symptoms (IDS-C) and the Calgary Depression Scale for Schizophrenia (CDSS). All patients underwent neuropsychological assessment. Physical activity was measured as hours spent on any regular physical activity (≥ or ˂90 min) per week. BDNF mRNA was measured in plasma using standardised procedures.Results: Patients with ≥90 min of physical activity per week had fewer depressive symptoms (P ˂0.001, Cohen's d = 0.48) and performed significantly better on working memory (P ˂ 0.001, d = 0.44) and executive functioning tasks (P ˂ 0.001, d = 0.50) compared to the ˂90-min group. BDNF mRNA was positively associated with physical activity (P = 0.046) and cognitive functioning (P = 0.037).Conclusions: Our study suggests a positive association between self-reported physical activity, cognitive function, mood and BDNF mRNA levels in severe mental disorders.

Gene-Environment Interactions in Psychiatry: Recent Evidence and Clinical Implications

PURPOSE OF REVIEW

We identify the recent evidence for gene-by-environment interaction studies in relation to psychiatric disorders. We focus on the key genotypic data as well as environmental exposures and how they interact to predict psychiatric disorders and psychiatric symptomatology. We direct our focus on the psychiatric outcomes that were focused on by the Psychiatric Genetics Consortium.

RECENT FINDINGS

Many of the studies focus on candidate gene approaches, with most of the studies drawing upon previous literature to decide the genes of interest. Other studies used a genome-wide approach. While some studies demonstrated positive replication of previous findings, replication is still an issue within gene-by-environment interaction studies. Gene-by-environment interaction research in psychiatry globally suggests some susceptibility to environmental exposures based on genotype; however, greater clarity is needed around the idea that genetic risk may not be disorder specific.

Hippocampal subfield volumes and childhood trauma in bipolar disorders

BACKGROUND

Alterations in hippocampal structure and function are present in bipolar disorder (BD). Childhood trauma is associated with risk for BD, and the several subfields of the hippocampus are differentially sensitive to the effects of stressors of the sort associated with risk for BD. The current study therefore sought to test the hypothesis that childhood trauma may be differentially associated with abnormal hippocampal subfield volumes in BD.

METHODS

104 participants with BD type I (BD-I, n = 56) or BD type II (BD-II, n = 48) and 81 healthy controls (HC) underwent high-resolution structural magnetic resonance neuroimaging. Hippocampal subfield volumes were determined using FreeSurfer. Childhood trauma was assessed with the Childhood Trauma Questionnaire (CTQ).

RESULTS

There were significant effects of diagnosis on intracranial volume corrected hippocampal subfield volumes bilaterally as well as a significant interaction between diagnosis and childhood trauma. Hippocampal volumes did not differ between the BD-I and BD-II subgroups but hippocampal volumes were smaller in both groups when compared to HC. There was a significant effect of childhood trauma on bilateral presubiculum volume as well as significant interactions between diagnosis and childhood trauma on bilateral CA1, presubiculum and subiculum volumes, the direction of which differed between individuals with BD (larger) and HC (smaller).

LIMITATIONS

Recall bias may influence the reliability of the retrospective assessment of childhood trauma experiences.

CONCLUSIONS

Childhood trauma demonstrates differential effects on hippocampal subfield volumes of BD and HC, particularly in hippocampal subfields involved in emotion regulation.

Telomere length is associated with childhood trauma in patients with severe mental disorders

Reduced telomere length (TL) and structural brain abnormalities have been reported in patients with schizophrenia (SZ) and bipolar disorder (BD). Childhood traumatic events are more frequent in SZ and BD than in healthy individuals (HC), and based on recent findings in healthy individuals could represent one important factor for TL and brain aberrations in patients. The study comprised 1024 individuals (SZ [n = 373]; BD [n = 249] and HC [n = 402]). TL was measured by quantitative polymerase chain reaction (qPCR), and childhood trauma was assessed using the Childhood Trauma Questionnaire (CTQ). Diagnosis was obtained by the Structured Clinical Interview (SCID) for the diagnostic and statistical manual of mental disorders-IV (DSM-IV). FreeSurfer was used to obtain regional and global brain volumes from T1-weighted magnetic resonance imaging (MRI) brain scans. All analyses were adjusted for current age and sex. Patients had on average shorter TL (F = 7.87, p = 0.005, Cohen's d = 0.17) and reported more childhood trauma experiences than HC (χ² = 148.9, p < 0.001). Patients with a history of childhood sexual, physical or emotional abuse had shorter TL relative to HC and to patients without a history of childhood abuse (F = 6.93, p = 0.006, Cohen's d = 0.16). After adjusting for childhood abuse, no difference in TL was observed between patients and HC (p = 0.12). There was no statistically significant difference in reported childhood abuse exposure or TL between SZ and BD. Our analyses revealed no significant associations between TL and clinical characteristics or brain morphometry. We demonstrate shorter TL in SZ and BD compared with HC and showed that TL is sensitive to childhood trauma experiences. Further studies are needed to identify the biological mechanisms of this relationship.

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.

Hippocampal subfield CA2+3 exhibits accelerated aging in Alcohol Use Disorder: A preliminary study

The profile of brain structural dysmorphology of individuals with Alcohol Use Disorders (AUD) involves disruption of the limbic system. In vivo imaging studies report hippocampal volume loss in AUD relative to controls, but only recently has it been possible to articulate different regions of this complex structure. Volumetric analysis of hippocampal regions rather than total hippocampal volume may augment differentiation of disease processes. For example, damage to hippocampal subfield cornu ammonis 1 (CA1) is often reported in Alzheimer's disease (AD), whereas deficits in CA4/dentate gyrus are described in response to stress and trauma. Two previous studies explored the effects of chronic alcohol use on hippocampal subfields: one reported smaller volume of the CA2+3 in alcohol-dependent subjects relative to controls, associated with years of alcohol consumption; the other, smaller volumes of presubiculum, subiculum, and fimbria in alcohol-dependent relative to control men.

The current study, conducted in 24 adults with DSM5-diagnosed AUD (7 women, 53.7 ± 8.8) and 20 controls (7 women, 54.1 ± 9.3), is the first to use FreeSurfer 6.0, which provides state-of-the art hippocampal parcellation, to explore the sensitivity of hippocampal sufields to alcoholism. T1- and T2- images were collected on a GE MR750 system with a 32-channel Nova head coil. FreeSurfer 6.0 hippocampal subfield analysis produced 12 subfields: parasubiculum; presubiculum; subiculum; CA1; CA2+3; CA4; GC-ML-DG (Granule Cell (GC) and Molecular Layer (ML) of the Dentate Gyrus (DG)); molecular layer; hippocampus-amygdala-transition-area (HATA); fimbria; hippocampal tail; hippocampal fissure; and whole volume for left and right hippocampi. A comprehensive battery of neuropsychological tests comprising attention, memory and learning, visuospatial abilities, and executive functions was administered.

Multiple regression analyses of raw volumetric data for each subfields by group, age, sex, hemisphere, and supratentorial volume (svol) showed significant effects of svol (p < .04) on nearly all structures (excluding tail and fissure). Volumes corrected for svol showed effects of age (fimbria, fissure) and group (subiculum, CA1, CA4, GC-ML-DG, HATA, fimbria); CA2+3 showed a diagnosis-by-age interaction indicating older AUD individuals had a smaller volume than would be expected for their age. There were no selective relations between hippocampal subfields and performance on neuropsychological tests, likely due to lack of statistical power.

The current results concur with the previous study identifying CA2+3 as sensitive to alcoholism, extend them by identifying an alcoholism-age interaction, and suggest an imaging phenotype distinguishing AUD from AD and stress/trauma.

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Whether alcohol use disorders (AUD) compromise hippocampal volume is disputed.

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A 32-channel head coil acquired high-resolution images.

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The hippocampus was segmented using FreeSurfer 6.0.

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Several subregions showed volume deficits in AUD relative to healthy controls.

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Cornu Ammonis 2+3 showed a alcoholism-by-age interaction.

Child maltreatment and psychosis

This paper reviews the literature on the association between experiences of child abuse and neglect and the development of psychoses. It then explores the premise that psychotic patients with a history of maltreatment may comprise a clinically and biological distinct subgroup. The review demonstrates that there is a growing consensus in the field that experiences of child maltreatment contribute to the onset of psychotic symptoms and psychotic disorders. There is also strong support for the premise that patients with psychotic disorders and histories of child maltreatment have distinct clinical characteristics and unique treatment needs, and emerging preliminary data to suggest psychotic patients with a history of maltreatment may comprise a distinct neurobiological subgroup. The mechanisms by which experiences of child maltreatment confers risk for psychotic disorders remains unknown, and the review highlights the value of incorporating translational research perspectives to advance knowledge in this area.

Changes in neuroplasticity following early-life social adversities: the possible role of brain-derived neurotrophic factor

Social adversities experienced in childhood can have a profound impact on the developing brain, leading to the emergence of psychopathologies in adulthood. Despite the burden this places on both the individual and society, the neurobiological aspects mediating this transition remain unclear. Recent advances in preclinical and clinical research have begun examining neuroplasticity-the nervous system's ability to form adaptive changes in response to new experience-in the context of early-life vulnerability to social adversities and plasticity-related alterations following such traumatic events. A key mediator of plasticity-related molecular processes is the brain-derived neurotrophic factor (BDNF), which has also been implicated in various psychiatric disorders related to childhood social adversities. Preclinical and clinical data suggest early-life social adversities (ELSA) might be associated with accelerated maturation of social network circuitry, a possible ontogenic adaptation to the adverse environment. Neural plasticity decreases by adulthood, lessening the efficacy of treatment in ELSA-related psychiatric disorders. However, literature data suggest that by increasing BDNF/TrkB signalling through antidepressant treatment a juvenile-like plasticity state can be induced, which allows for reorganization of the social circuitry when guided by psychotherapy and surrounded by a safe and positive environment.

Childhood trauma in mood disorders: Neurobiological mechanisms and implications for treatment

A contemporary model for the pathogenesis of mood disorders (bipolar and depressive disorders) involves gene-environmental interaction, with genetic predisposition, epigenetic regulation, and environmental effects. Among multiple environmental factors, the experience of childhood trauma can be connected with the pathogenesis, course and the treatment of mood disorders. Patients with mood disorders have the greater frequency of childhood trauma compared with the general population, and adverse childhood experiences can exert a negative impact on their clinical course. In this article, the neurobiological mechanisms of childhood trauma are presented. The influence of negative childhood experiences on the central nervous system can result in many structural and functional changes of the brain, including such structures as hippocampus and amygdala, associated with the development of bipolar and depressive illnesses. Interaction of several genes with childhood trauma to produce pathological, clinical phenomena in adulthood has been demonstrated, the most important in this respect being the serotonin transporter gene and the FKBP5 gene playing an important role in the pathogenesis of mood disorders. Neurobiological effects can also involve epigenetic mechanisms such as DNA methylation which can exert an effect on brain function over long-term periods. Somatic effects of childhood trauma include disturbances of stress axis and immune-inflammatory mechanisms as well as metabolic dysregulation. Negative childhood experiences may also bear implications for the treatment of mood disorders. In the article, the impact of such experiences on the treatment of mood disorders will be discussed, especially in the context of treatment -resistance to antidepressants and mood-stabilizing drugs.

Neuroimaging hippocampal subfields in schizophrenia and bipolar disorder: A systematic review and meta-analysis

The hippocampus is a complex structure consisting of subregions with specialized cytoarchitecture and functions. Magnetic resonance imaging (MRI) studies in psychotic disorders show hippocampal subfield abnormalities, but affected regions differ between studies. We here present an overview of hippocampal anatomy and function relevant to psychosis, and the first systematic review and meta-analysis of MRI studies of hippocampal subfield morphology in schizophrenia and bipolar disorder. Twenty-one MRI studies assessing hippocampal subfield volumes or shape in schizophrenia or bipolar disorder were included (n 15-887 subjects). Nine volumetric group comparison studies (total n = 2593) were included in random effects meta-analyses of group differences. The review showed mixed results, with volume reductions reported in most subfields in schizophrenia and bipolar disorder. Volumetric studies using ex-vivo based image analysis templates corresponded best with the shape studies, with CA1 as the most affected region. The meta-analyses showed volume reductions in all subfields in schizophrenia and bipolar disorder compared to healthy controls (all p < .005; schizophrenia: d = 0.28-0.49, bipolar disorder: d = 0.20-0.35), and smaller left CA2/3 and right subiculum in schizophrenia than bipolar disorder. In conclusion, the hippocampal subfields appear to be differently affected in psychotic disorders. However, due to the lack of control for putative confounders such as medication, alcohol and illicit substance use, and illness stage, the results from the meta-analysis should be interpreted with caution. Methodological subfield segmentation weaknesses should be addressed in future studies.