The risk for major depression conferred by childhood maltreatment is multiplied by BDNF and SERT genetic vulnerability: a replication study

Interaction of childhood trauma with BDNF and FKBP5 gene polymorphisms in predicting burnout in general occupational groups

Both the BDNF gene rs6265 and the FKBP5 gene rs1360780 polymorphisms are independently associated with adult psychotic-like experiences, when exposed to high childhood abuse; however, it remains unclear whether the relationship between childhood abuse and burnout is moderated by these two single nucleotide polymorphisms (SNPs). Furthermore, there is an interaction between glucocorticoid receptor transcriptional activity and BDNF signaling. Therefore, we investigated the interaction of these two SNPs with childhood trauma in predicting burnout. We recruited 990 participants (mean age 33.06 years, S.D. = 6.31) from general occupational groups and genotyped them for rs6265 and rs1360780. Burnout, childhood trauma, resilience, and job stress were measured through a series of rating scales. Gene-by-environment and gene-by-gene-by-environment interactions were examined using linear hierarchical regression and PROCESS macro in SPSS. Covariates included demographics and resilience. We found that rs6265 moderated the association between job stress and emotional exhaustion. Both rs6265 and rs1360780 moderated the association between childhood abuse and cynicism. There was significant interaction of childhood abuse × rs6265 × rs1360780 on emotional exhaustion and reduced personal accomplishment, so that rs6265 CC genotype and rs1360780 TT genotype together predicted higher levels of emotional exhaustion under high childhood abuse, while rs6265 TT genotype and rs1360780 CC genotype together exerted a resilient effect on reduced personal accomplishment in the face of childhood abuse. Our findings suggest that the rs6265 CC genotype and rs1360780 TT genotype may jointly contribute to increased risk of burnout under childhood trauma.

Influence of BDNF Val66Met genetic polymorphism in Major Depressive Disorder and Body Mass Index: Evidence from a meta-analysis of 6481 individuals

BACKGROUND

Major depressive disorder (MDD) and obesity are global health problems that frequently co-occur. Among shared etiological factors, genetic variation at the brain-derived neurotrophic factor (BDNF) gene is interesting since its implication in energy balance regulation, food intake and synaptic function. Thus, the aim of this study was to investigate the influence of the BDNF Val66Met polymorphism in relation to MDD and body mass index (BMI) in two large independent cohorts.

METHODS

The sample consisted of 2646 individuals with MDD and 3835 controls from the PISMA-ep and Radiant studies. Linear regressions were performed to test the association between the polymorphism and BMI and the interaction between the polymorphism and MDD on BMI. A meta-analysis across cohorts was conducted.

RESULTS

No association was found between the polymorphism and BMI. However, we found an association with MDD, showing these individuals higher BMI than controls in both cohorts. No differences were found in BMI depending on Val66Met genotype and no interaction between this polymorphism and MDD in relation to BMI was found. Although a tendency towards an interaction was found in the Radiant sample, the results of the meta-analysis did not support this finding.

LIMITATIONS

The use of self-reported height and weight measures to calculate BMI values.

CONCLUSIONS

We provide evidence for an association between BMI and MDD confirming previous results. Our meta-analysis including two large cohorts showed no interaction between BDNF, BMI and MDD. Future studies will be needed to confirm the role of this polymorphism in the relationship between BMI and MDD.

Time moderates the interplay between 5-HTTLPR and stress on depression risk: gene x environment interaction as a dynamic process

The serotonin-transporter-linked promoter region (5-HTTLPR) has been widely investigated as contributing to depression vulnerability. Nevertheless, empirical research provides wide contrasting findings regarding its involvement in the etiopathogenesis of the disorder. Our hypothesis was that such discrepancy can be explained considering time as moderating factor. We explored this hypothesis, exploiting a meta analytic approach. We searched PubMed, PsychoINFO, Scopus and EMBASE databases and 1096 studies were identified and screened, resulting in 22 studies to be included in the meta-analyses. The effect of the 5-HTTLPR x stress interaction on depression risk was found to be moderated by the following temporal factors: the duration of stress (i.e. chronic vs. acute) and the time interval between end of stress and assessment of depression (i.e. within 1 year vs. more than 1 year). When stratifying for the duration of stress, the effect of the 5-HTTLPR x stress interaction emerged only in the case of chronic stress, with a significant subgroup difference (p = 0.004). The stratification according to time interval revealed a significant interaction only for intervals within 1 year, though no difference between subgroups was found. The critical role of time interval clearly emerged when considering only chronic stress: a significant effect of the 5-HTTLPR and stress interaction was confirmed exclusively within 1 year and a significant subgroup difference was found (p = 0.01). These results show that the 5-HTTLPR x stress interaction is a dynamic process, producing different effects at different time points, and indirectly confirm that s-allele carriers are both at higher risk and more capable to recover from depression. Overall, these findings expand the current view of the interplay between 5-HTTLPR and stress adding the temporal dimension, that results in a three-way interaction: gene x environment x time.

Altered centromedial amygdala functional connectivity in adults is associated with childhood emotional abuse and predicts levels of depression and anxiety

BACKGROUND

Childhood maltreatment is significantly associated with greater occurrence of mental disorders in adulthood such as depression and anxiety. As a key node of the limbic system, the amygdala is engaged in emotional processing and regulation and is dysfunctional in many psychiatric disorders. The present study aimed at exploring the association between childhood maltreatment and amygdala-based functional networks and their potential contributions to depression and anxiety.

METHODS

Totally 90 Chinese healthy volunteers participated in a resting-state fMRI experiment. Levels of childhood maltreatment experience were assessed using the Childhood Trauma Questionnaire (CTQ-SF) as well as levels of depression and anxiety. Associations between CTQ-SF scores and bilateral amygdala gray matter volume and resting-state functional connectivity (RSFC) of the amygdala and selected regions of interest were analyzed using multiple regression analyses with sex and age as covariates. A subsequent moderation analysis was performed to identify whether associations were predictive of depression and anxiety levels.

RESULTS

Childhood maltreatment was significantly negatively associated with RSFC between left amygdala and anterior insula. Further sub-region analyses revealed that this negative association only occurred for the left centromedial amygdala subregion, which subsequently moderated the relationship between levels of childhood emotional abuse and depression / anxiety.

LIMITATIONS

No psychiatric patients were involved and specific neural associations with different childhood maltreatment subtypes need to be examined in future studies.

CONCLUSION

The present findings provide evidence for altered RSFC of centromedial amygdala and the anterior insula associated with childhood maltreatment and which moderate levels of depression and anxiety in adulthood.

Per1 gene polymorphisms influence the relationship between brain white matter microstructure and depression risk

BACKGROUND

Circadian rhythm was involved in the pathogenesis of depression. The detection of circadian genes and white matter (WM) integrity achieved increasing focus for early prediction and diagnosis of major depressive disorder (MDD). This study aimed to explore the effects of PER1 gene polymorphisms (rs7221412), one of the key circadian genes, on the association between depressive level and WM microstructural integrity.

MATERIALS AND METHODS

Diffusion tensor imaging scanning and depression assessment (Beck Depression Inventory, BDI) were performed in 77 healthy college students. Participants also underwent PER1 polymorphism detection and were divided into the AG group and AA group. The effects of PER1 genotypes on the association between the WM characteristics and BDI were analyzed using tract-based spatial statistics method.

RESULTS

Compared with homozygous form of PER1 gene (AA), more individuals with risk allele G of PER1 gene (AG) were in depression state with BDI cutoff of 14 (χ² = 7.37, uncorrected p = 0.007). At the level of brain imaging, the WM integrity in corpus callosum, internal capsule, corona radiata and fornix was poorer in AG group compared with AA group. Furthermore, significant interaction effects of genotype × BDI on WM characteristics were observed in several emotion-related WM tracts. To be specific, the significant relationships between BDI and WM characteristics in corpus callosum, internal capsule, corona radiata, fornix, external capsule and sagittal stratum were only found in AG group, but not in AA group.

CONCLUSION

Our findings suggested that the PER1 genotypes and emotion-related WM microstructure may provide more effective measures of depression risk at an early phase.

DNA methylations of brain-derived neurotrophic factor exon VI are associated with major depressive disorder and antidepressant-induced remission in females

BACKGROUND

Brain-derived neurotrophic factor (BDNF) has been suggested to play important roles in major depressive disorder (MDD) and antidepressant treatment. The main purpose of this study was to evaluate the association of DNA methylation changes in the BDNF gene with MDD and antidepressant treatment.

METHODS

A total of 291 MDD patients and 100 healthy controls were included and followed up for 6 weeks. The Hamilton Depression Rating Scale-17 (HDRS-17) was used to measure treatment improvement. The life events scales (LES) and childhood trauma questionnaire (CTQ) were used to rate recent and early life stress. DNA methylation levels of CpG sites in the BDNF gene were measured.

RESULTS

Two CpG sites in BDNF exon VI (BDNF133 and BDNF134) were demonstrated to have significantly higher methylation in MDD patients than in controls (both FDR-adjusted P = 0.001). A logistics regression model indicated that the interaction between the hypermethylation of BDNF133 and negative subscore of LES was associated to MDD (OR=0.0075, P<0.001). Methylation of BDNF140 at baseline was significantly elevated in remitters (FDR-adjusted P = 0.046) at week 6. In subgroup analyses, these findings could be replicated in females, but not in males.

LIMITATIONS

The methylation status of BDNF after 6 weeks of antidepressant treatment was not measured and the DNA methylation were detected in peripheral blood cells.

CONCLUSIONS

These findings highlight gender-specific alteration of methylation at several CpG sites in BDNF exon VI as a promising candidate indicator of MDD and antidepressant-induced remission.

The Association of Childhood Maltreatment with Adulthood Mental Disorders and Suicidality in Korea: a Nationwide Community Study

BACKGROUND

Although childhood maltreatment is a known risk factor for adulthood mental health, the impact of different types of childhood maltreatment on mental disorders is not yet clear. This study explored the association of each type of childhood maltreatment with adulthood mental disorders and suicidality in South Korea.

METHODS

A total of 5,102 individuals from the general populations over the age of 18 responded to the Korean version of the Composite International Diagnostic Interview and questions about childhood maltreatment (emotional neglect, psychological abuse, physical abuse, and sexual abuse). To evaluate the odds ratio for mental disorders and suicidality associated with each type of childhood maltreatment, we used logistic regression analysis.

RESULTS

About 17.0% of the respondents reported having experienced a type of maltreatment in childhood. According to the type, 9.4% reported physical abuse, 9.3% reported emotional neglect, 7.9% reported psychological abuse, and 3.8% reported sexual abuse. Exposure to each type of childhood maltreatment was associated with most types of mental disorders after adjusting for sociodemographic factors. Each type of childhood maltreatment victim was associated with suicidality (suicidal ideations, suicide plans, and suicide attempts). Dose-response patterns for suicide attempts were observed in all types of victims. Moreover, the respondents who experienced frequent childhood emotional neglect were 14 times more likely to have attempted suicide.

CONCLUSION

Childhood maltreatment was associated with mental health in adulthood. The findings show the need for early detection and intervention of victims of childhood maltreatment to minimize its negative impact on adult mental health.

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.

Cognition in Recent Suicide Attempts: Altered Executive Function

Background: Neuropsychological alterations can lead to inaccurate perception, interpretation, and response to environmental information, which could be a risk factor for suicide. Methods: Ninety-six subjects were recruited from the Psychiatry Department of the Araba University Hospital-Santiago, including 20 patients with a recent attempt and diagnosis of major depressive disorder (MDD) according to DSM-V, 33 MDD patients with history of attempted suicide, 23 non-attempter MDD patients, and 20 healthy controls. All participants underwent a clinical interview and neuropsychological assessment on the following cognitive domains: working memory, processing speed, decision-making, executive function, and attention. Backward multiple regressions were performed adjusting for significant confounding variables. For group comparisons, ANOVA and Bonferroni post-hoc tests were performed with a p < 0.05 significance level. Results: The patient groups did not differ regarding severity of depression and stressful events in the last 6 months. In comparison to healthy controls, depressed patients with lifetime suicide attempts had more general trauma (p = 0.003), emotional abuse (p = 0.003), emotional negligence (p = 0.006), and physical negligence (p = 0.009), and depressed patients with recent suicide attempts had experienced more child sexual abuse (p = 0.038). Regarding neuropsychological assessment, all patient groups performed significantly worse than did healthy controls in processing speed, decision-making, and attention. Comparisons between patient groups indicated that recent suicide attempters had poorer performance on executive function in comparison to both depressed lifetime attempters and depressed non-attempters (B = 0.296, p = 0.019, and B = 0.301, p = 0.028, respectively). Besides, women with recent attempts had slightly better scores on executive function than males. Regarding the rest of the cognitive domains, there were no significant differences between groups. Conclusion: Executive function performance is altered in recent suicide attempts. As impaired executive function can be risk factor for suicide, preventive interventions on suicide should focus on its assessment and rehabilitation.

Brain on food: The neuroepigenetics of nutrition

Humans have known for millennia that nutrition has a profound influence on health and disease, but it is only recently that we have begun mapping the mechanisms via which the dietary environment impacts brain physiology and behavior. Here we review recent evidence on the effects of energy-dense and methionine diets on neural epigenetic marks, gene expression, and behavior in invertebrate and vertebrate model organisms. We also discuss limitations, open questions, and future directions in the emerging field of the neuroepigenetics of nutrition.

Childhood maltreatment history and attention bias variability in healthy adult women: role of inflammation and the BDNF Val66Met genotype

Childhood maltreatment has been associated with greater attention bias to emotional information, but the findings are controversial. Recently, a novel index of attention bias, i.e., attention bias variability (ABV), has been developed to better capture trauma-related attentional dysfunction. However, ABV in relation to childhood trauma has not been studied. Here, we examined the association of childhood maltreatment history with attention bias/ABV in 128 healthy adult women. Different types of childhood maltreatment were assessed with the Childhood Trauma Questionnaire. Attention bias/ABV was measured by the dot-probe task. Possible mechanisms whereby childhood maltreatment affects attention bias/ABV were also explored, focusing on blood proinflammatory markers and the BDNF Val66Met polymorphism. We observed a significant positive correlation between childhood emotional abuse and ABV (P = 0.002). Serum high-sensitivity tumor necrosis factor-α levels were significantly positively correlated with ABV (P < 0.001), but not with childhood maltreatment. Jonckheere-Terpstra trend test showed a significant tendency toward greater ABV with increasing numbers of the BDNF Met alleles (P = 0.021). A two-way analysis of variance further revealed that the genotype-by-emotional abuse interaction for ABV was significant (P = 0.022); individuals with the Val/Met and Met/Met genotypes exhibited even greater ABV when childhood emotional abuse was present. These results indicate that childhood emotional abuse can have a long-term negative impact on emotional attention control. Increased inflammation may be involved in the mechanism of ABV, possibly independently of childhood maltreatment. The BDNF Met allele may dose-dependently increase ABV by interacting with childhood emotional abuse.

Prevalence and correlates of major depressive disorder: a systematic review

OBJECTIVES

Major depressive disorder (MDD) is one of the most disabling mental illnesses and it has a significant impact on society. This review aims to provide updated scientific evidence about the epidemiology of MDD.

METHODS

A systematic literature review of the PubMed and MEDLINE databases was performed to identify articles on the prevalence of MDD and its correlates. The search was restricted to manuscripts published between January 2001 and December 2018.

RESULTS

Sixty-three articles were included in the review. The lifetime prevalence of MDD ranged from 2 to 21%, with the highest rates found in some European countries and the lowest in some Asian countries. The main sociodemographic correlates were separated/divorced marital status and female gender. Child abuse, intimate partner violence, and comorbidity with other physical and mental disorders also were consistently associated with MDD across the reviewed studies.

CONCLUSIONS

MDD is a highly prevalent condition worldwide. There are remarkable interregional differences in the disorder's prevalence, as well as in certain sociodemographic correlates. MDD is also highly comorbid with physical and mental health problems.

Interactions of childhood maltreatment and genetic variations in adult depression: A systematic review

Background Childhood maltreatment (CM) significantly increases the risk of adulthood psychopathology. Interplay between susceptible genetic variations and CM contributes to the occurrence of depression. This review aims to systematically synthesize the relationships between genetic variations and depression among those exposed to CM. Methods Electronic databases and gray literature to March 31st, 2020 were searched for literature on the topic of depression and CM limited to English-language. Data extraction and quality assessment of key study characteristics were conducted. Qualitative approaches were used to synthesize the findings. Results The initial search resulted in 9185 articles. A total of 29 articles that met the eligibility criteria were included in this review. High heterogeneity was identified regarding the study sample ages, candidate genes and SNPs, the categorization of CM and depression. The findings of this review include several frequently studied genes (5-HTTLPR, CRHR1, BDNF, CREB1, FKBP5, IL1B, NTRK2, and OXTR). Both consistent and inconsistent findings were identified. Overall, the interplay of CM with CREB1-rs2253206 significantly increased the risk of depression. In contrast, CRHR1-TCA haplotype (rs7209436, rs4792887, rs110402), CRHR1-rs17689882, and CRHR1-rs110402 showed protective effects on depression and depressive symptoms among individuals with a history of maltreatment. Limitations Due to clinical and methodological diversity of the studies a qualitative approach was used. Conclusion This review firstly provides a comprehensive overview of the interplay between CM and genetic variations in adult depression. Future etiological explorations should focus on the above-identified genes for down-stream exploration and address the issues and challenges of gene by environment studies.

Prevalence and correlates of major depressive disorder: a systematic review

OBJECTIVES

Major depressive disorder (MDD) is one of the most disabling mental illnesses and it has a significant impact on society. This review aims to provide updated scientific evidence about the epidemiology of MDD.

METHODS

A systematic literature review of the PubMed and MEDLINE databases was performed to identify articles on the prevalence of MDD and its correlates. The search was restricted to manuscripts published between January 2001 and December 2018.

RESULTS

Sixty-three articles were included in the review. The lifetime prevalence of MDD ranged from 2 to 21%, with the highest rates found in some European countries and the lowest in some Asian countries. The main sociodemographic correlates were separated/divorced marital status and female gender. Child abuse, intimate partner violence, and comorbidity with other physical and mental disorders also were consistently associated with MDD across the reviewed studies.

CONCLUSIONS

MDD is a highly prevalent condition worldwide. There are remarkable interregional differences in the disorder's prevalence, as well as in certain sociodemographic correlates. MDD is also highly comorbid with physical and mental health problems.

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.

Prognosis and Improved Outcomes in Major Depression: A Review

(Reprinted from Transl Psychiatry. 2019 Apr 3; 9(1):127. Open access; is licensed under a Creative Commons Attribution 4.0 International License).

Interactions between the combined genotypes of 5-HTTLPR and BDNF Val66Met polymorphisms and parenting on adolescent depressive symptoms: A three-year longitudinal study

BACKGROUND

The importance of multiple genes-environment interaction (G × E) has been highlighted in studies on depressive symptoms. 5-HTTLPR and BDNF Val66Met polymorphisms, with functional interconnection, have been implicated in the pathophysiology of depressive symptoms. However, little is understood about whether the interaction of 5-HTTLPR, BDNF Val66Met and parenting fits better with the epistatic or cumulative manner.

METHODS

865 adolescents (T1: M_age = 12.32, 50.2% girls) were included in a three-year interval longitudinal design. Standardized questionares about parenting and depressive symptoms were collected. Saliva samples were collected for genotyping.

RESULTS

Neither the concurrent nor longitudinal interaction of 5-HTTLPR, BDNF Val66Met and parenting (G × G × E) showed significant effects on depressive symptoms. The interaction between cumulative genotypes and positive parenting (CG × E) was significant, with the strong differential susceptibility model, for depressive symptoms concurrently but not longitudinally after statistical correction. Adolescents who carried 3 (i.e. SS and Val/Met, L allele and Val/Val) and 4 (i.e. SS and Val/Val), not 1 (i.e. L allele and Met/Met) or 2 cumulative susceptibility alleles (i.e. SS and Met/Met, L allele and Val/Met), reported fewer depressive symptoms if they had experienced higher levels of positive parenting, and more symptoms under lower levels of positive parenting.

LIMITATIONS

This study did not examine the 5-HTTLPR triallelic (rs25531) marker and did not include an external sample.

CONCLUSIONS

The combined effects of 5-HTTLPR and BDNF Val66Met polymorphisms functioned in a manner of cumulative rather than epistatic in response to positive parenting on early adolescent depressive symptoms.

Interactive effects of genetic polymorphisms and childhood adversity on brain morphologic changes in depression

The etiology of depression is characterized by the interplay of genetic and environmental factors and brain structural alteration. Childhood adversity is a major contributing factor in the development of depression. Interactions between childhood adversity and candidate genes for depression could affect brain morphology via the modulation of neurotrophic factors, serotonergic neurotransmission, or the hypothalamus-pituitary-adrenal (HPA) axis, and this pathway may explain the subsequent onset of depression. Childhood adversity is associated with structural changes in the hippocampus, amygdala, anterior cingulate cortex (ACC), and prefrontal cortex (PFC), as well as white matter tracts such as the corpus callosum, cingulum, and uncinate fasciculus. Childhood adversity showed an interaction with the brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism, serotonin transporter-linked promoter region (5-HTTLPR), and FK506 binding protein 51 (FKBP5) gene rs1360780 in brain morphologic changes in patients with depression and in a non-clinical population. Individuals with the Met allele of BDNF Val66Met and a history of childhood adversity had reduced volume in the hippocampus and its subfields, amygdala, and PFC and thinner rostral ACC in a study of depressed patients and healthy controls. The S allele of 5-HTTLPR combined with exposure to childhood adversity or a poorer parenting environment was associated with a smaller hippocampal volume and subsequent onset of depression. The FKBP5 gene rs160780 had a significant interaction with childhood adversity in the white matter integrity of brain regions involved in emotion processing. This review identified that imaging genetic studies on childhood adversity may deepen our understanding on the neurobiological background of depression by scrutinizing complicated pathways of genetic factors, early psychosocial environments, and the accompanying morphologic changes in emotion-processing neural circuitry.

CA, Kasper S. Prognosis and improved outcomes in major depression: a review

Treatment outcomes for major depressive disorder (MDD) need to be improved. Presently, no clinically relevant tools have been established for stratifying subgroups or predicting outcomes. This literature review sought to investigate factors closely linked to outcome and summarize existing and novel strategies for improvement. The results show that early recognition and treatment are crucial, as duration of untreated depression correlates with worse outcomes. Early improvement is associated with response and remission, while comorbidities prolong course of illness. Potential biomarkers have been explored, including hippocampal volumes, neuronal activity of the anterior cingulate cortex, and levels of brain-derived neurotrophic factor (BDNF) and central and peripheral inflammatory markers (e.g., translocator protein (TSPO), interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor alpha (TNFα)). However, their integration into routine clinical care has not yet been fully elucidated, and more research is needed in this regard. Genetic findings suggest that testing for CYP450 isoenzyme activity may improve treatment outcomes. Strategies such as managing risk factors, improving clinical trial methodology, and designing structured step-by-step treatments are also beneficial. Finally, drawing on existing guidelines, we outline a sequential treatment optimization paradigm for selecting first-, second-, and third-line treatments for acute and chronically ill patients. Well-established treatments such as electroconvulsive therapy (ECT) are clinically relevant for treatment-resistant populations, and novel transcranial stimulation methods such as theta-burst stimulation (TBS) and magnetic seizure therapy (MST) have shown promising results. Novel rapid-acting antidepressants, such as ketamine, may also constitute a paradigm shift in treatment optimization for MDD.

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.

MicroRNA-200a Targets Cannabinoid Receptor 1 and Serotonin Transporter to Increase Visceral Hyperalgesia in Diarrhea-predominant Irritable Bowel Syndrome Rats

Background/Aims

MicroRNAs (miRNAs) were reported to be responsible for intestinal permeability in diarrhea-predominant irritable bowel syndrome (IBS-D) rats in our previous study. However, whether and how miRNAs regulate visceral hypersensitivity in IBS-D remains largely unknown.

Methods

We established the IBS-D rat model and evaluated it using the nociceptive visceral hypersensitivity test, myeloperoxidase activity assay, restraint stress-induced defecation, and electromyographic (EMG) activity. The distal colon was subjected to miRNA microarray analysis followed by isolation and culture of colonic epithelial cells (CECs). Bioinformatic analysis and further experiments, including dual luciferase assays, quantitative real-time polymerase chain reaction, western blot, and enzyme-linked immunosorbent assay, were used to detect the expression of miRNAs and how it regulates visceral hypersensitivity in IBS-D rats.

Results

The IBS-D rat model was successfully established. A total of 24 miRNAs were differentially expressed in the distal colon of IBS-D rats; 9 were upregulated and 15 were downregulated. Among them, the most significant upregulation was miR-200a, accompanied by downregulation of cannabinoid receptor 1 (CNR1) and serotonin transporter (SERT). MiR-200a mimic markedly inhibited the expression of CNR1/SERT. Bioinformatic analysis and luciferase assay confirmed that CNR1/SERT are direct targets of miR-200a. Rescue experiments that overexpressed CNR1/SERT significantly abolished the inhibitory effect of miR-200a on the IBS-D rats CECs.

Conclusions

This study suggests that miR-200a could induce visceral hyperalgesia by targeting the downregulation of CNR1 and SERT, aggravating or leading to the development and progression of IBS-D. MiR-200a may be a regulator of visceral hypersensitivity, which provides potential targets for the treatment of IBS-D.

Prevalence and correlates of major depression in Granada, Spain: Results from the GranadΣp study

BACKGROUND

Major depression is one of the world's leading causes of disability. Up-to-date information about the epidemiology of this disorder is key to health care planning.

AIM

The aim of our study is to report prevalence and correlates of current major depressive disorder (MDD) in the province of Granada, Southern Spain.

METHODS

The GranadΣp is a cross-sectional study based on a community-dwelling adult population living in the province of Granada, Southern Spain. Community-dwelling adults aged 18-80 years ( n = 810) were interviewed using the Mini-International Neuropsychiatric Interview (MINI). A variety of exposure assessments were also undertaken.

RESULTS

Point (2 weeks) prevalence of MDD in the Granada population was 5.6%. Positive family history of mental illness, high degree of neuroticism, high number of life threatening events (LTE), poor physical health status, cognitive impairment and cannabis use were independently associated with MDD in the multivariate regression model. Being female was also associated with MDD, but the significance disappeared after adjusting for neuroticism and physical health.

CONCLUSION

Prevalence of MDD in the Granada population is higher than expected. The effects of the financial crisis could be partially accountable for this excess in prevalence. Six variables were found to be independently associated with MDD. Association between female sex and depression may be partially explained by the confounding effect of neuroticism.

BDNF and NRG1 polymorphisms and temperament in selective serotonin reuptake inhibitor-treated patients with major depression

OBJECTIVE

We investigated the separate effects of and possible interactions between the functional polymorphisms of brain-derived neurotrophic factor (BDNF) rs11030101, BDNF rs61888800, and neuregulin-1 (NRG1) rs3924999 and NRG1 rs6994992 on change of temperament scores in a clinical sample of subjects with major depression (MDD), who received selective serotonin reuptake inhibitor treatment for a period of 6 weeks.

METHODS

The study population consisted of 98 Finnish individuals with MDD. They were assessed by the 107-item Temperament and Character Inventory temperament questionnaire (version IX) and the Montgomery-Åsberg Depression Rating Scale (MADRS). In general linear univariate models (GLM) for novelty seeking (NS) or reward dependence (RD) change age, gender, MADRS score change and BDNF and NRG1 genotypes were used as explaining explanatory variables.

RESULTS

Mean comparisons between corresponding temperament dimensions and genotypes showed significant differences between NS change and BDNF rs61888800 T-carrying status (mean difference: GG 0.30, GT/TT 2.47, p=0.022, t-test) and between RD change and NRG1 rs3924999 A-carrying status (mean difference: GG 1.21, GA/AA -0.33, p=0.003). In GLM models for NS change the significant predictors comprised BDNF rs61888800 T-carrying status, age and MADRS score change (model 1), and additionally NRG1 rs6994992 T-carrying status (model 2). For RD change the predictors included NRG1 rs3924999 A-carrying status, age and MADRS score change (model 1) and additionally gender (model 2).

CONCLUSION

According to the current results both BDNF and NRG1 are associated with temperament traits during depression. These results warrant further studies regarding the impact of this association on depression recovery.

Gene-environment interactions between stress and 5-HTTLPR in depression: A meta-analytic update

BACKGROUND

Meta-analyses have yielded contradictory findings concerning the role of 5-HTTLPR in interaction with stress (GxE) in depression. The current meta-analysis investigates if these contradictory findings are a result of differences between studies in methodological approaches towards the assessment of stress and depression.

METHODS

After performing a systematic database search (February to December 2016), first, a meta-analysis was used to investigate the total effect size and publication bias. Second, stratified meta-analyses were used to investigate the potential moderating influence of different methodological approaches on heterogeneity of study findings. Third, a meta-regression was used to investigate the combined influence of the methodological approaches on the overall effect size.

RESULTS

Results showed a small but significant effect of 5-HTTLPR in interaction with stress in the prediction of depression (OR[95%CI] = 1.18[1.09; 1.28], n = 48 effect sizes from 51 studies, totaling 51,449 participants). There was no evidence of publication bias. Heterogeneity of effect sizes was a result of outliers and not due to different methodological approaches towards the assessment of stress and depression. Yet, there was some evidence that studies adopting a categorical and interview approach to the assessment of stress report higher GxE effects, but further replication of this finding is needed.

LIMITATIONS

A large amount of heterogeneity (i.e., 46%) was not explained by the methodological factors included in the study and there was a low response rate of invited studies.

CONCLUSIONS

The current meta-analysis provides new evidence for the robustness of the interaction between stress and 5-HTTLPR in depression.

No gene-by-environment interaction of BDNF Val66Met polymorphism and childhood maltreatment on anxiety sensitivity in a mixed race adolescent sample

Background: Anxiety disorders in youth are attributable to multiple causal mechanisms, comprising biological vulnerabilities, such as genetics and temperament, and unfavourable environmental influences, such as childhood maltreatment (CM). Objective: A gene-environment (G x E) interaction study was conducted to determine the interactive effect of the BDNF Val66Met polymorphism and CM to increase susceptibility to anxiety sensitivity (AS) in a sample of mixed race adolescents. Method: Participants (n = 308, mean age = 15.8 years) who were all secondary school students and who completed measures for AS and CM were genotyped for the BDNF Val66Met polymorphism. Hierarchical multiple regression analysis was conducted to assess G x E influences on AS. Age and gender were included in the models as covariates as age was significantly associated with AS total score (p < .05), and females had significantly higher AS scores than males (p < .05). Results: A main effect of CM on AS was evident (p < .05), however, no main effect of BDNF genotype on AS was observed (p > .05). A non-significant G x E effect on AS was revealed (p < .05). Conclusions: Our results suggest that CM does not have a moderating role in the relationship between the BDNF Val66Met genotype and the increased risk of anxiety-related phenotypes, such as AS. Given the exploratory nature of this study, findings require replication in larger samples and adjustment for population stratification to further explore the role of BDNF Val66Met and CM on AS in mixed race adolescents.

Consensus paper of the WFSBP Task Force on Genetics: Genetics, epigenetics and gene expression markers of major depressive disorder and antidepressant response

Major depressive disorder (MDD) is a heritable disease with a heavy personal and socio-economic burden. Antidepressants of different classes are prescribed to treat MDD, but reliable and reproducible markers of efficacy are not available for clinical use. Further complicating treatment, the diagnosis of MDD is not guided by objective criteria, resulting in the risk of under- or overtreatment. A number of markers of MDD and antidepressant response have been investigated at the genetic, epigenetic, gene expression and protein levels. Polymorphisms in genes involved in antidepressant metabolism (cytochrome P450 isoenzymes), antidepressant transport (ABCB1), glucocorticoid signalling (FKBP5) and serotonin neurotransmission (SLC6A4 and HTR2A) were among those included in the first pharmacogenetic assays that have been tested for clinical applicability. The results of these investigations were encouraging when examining patient-outcome improvement. Furthermore, a nine-serum biomarker panel (including BDNF, cortisol and soluble TNF-α receptor type II) showed good sensitivity and specificity in differentiating between MDD and healthy controls. These first diagnostic and response-predictive tests for MDD provided a source of optimism for future clinical applications. However, such findings should be considered very carefully because their benefit/cost ratio and clinical indications were not clearly demonstrated. Future tests may include combinations of different types of biomarkers and be specific for MDD subtypes or pathological dimensions.

A biological perspective on differences and similarities between burnout and depression

To compare and contrast burnout and depression is not only a conceptual issue, but may deliver important directions for treatment approaches and stabilize the awareness of disease which is essential for affected individuals. Because of the symptomatic overlap, it is a subject of multidimensional research and discussion to find specific signatures to differentiate between the two phenomena or to present evidence that they are different aspects of the same disorder. Both pathologies are regarded as stress-related disorders. Therefore, in this review burnout and depression are discussed on the basis of biological parameters, mainly heart rate variability (HRV) and brain-derived neurotrophic factor (BDNF), which are crucial to the stress response system. It emerges that instead of finding one specific discriminating marker, future research should rather concentrate on elaborating indices for burnout and depression which integrate combinations of parameters found in genetics, neurobiology, physiology and environment.

Childhood trauma, BDNF Val66Met and subclinical psychotic experiences. Attempt at replication in two independent samples

Childhood trauma exposure is a robust environmental risk factor for psychosis. However, not all exposed individuals develop psychotic symptoms later in life. The Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism (rs6265) has been suggested to moderate the psychosis-inducing effects of childhood trauma in clinical and nonclinical samples. Our study aimed to explore the interaction effect between childhood trauma and the BDNF Val66Met polymorphism on subclinical psychotic experiences (PEs). This was explored in two nonclinical independent samples: an undergraduate and technical-training school student sample (n = 808, sample 1) and a female twin sample (n = 621, sample 2). Results showed that childhood trauma was strongly associated with positive and negative PEs in nonclinical individuals. A BDNF Val66Met x childhood trauma effect on positive PEs was observed in both samples. These results were discordant in terms of risk allele: while in sample 1 Val allele carriers, especially males, were more vulnerable to the effects of childhood trauma regarding PEs, in sample 2 Met carriers presented higher PEs scores when exposed to childhood trauma, compared with Val carriers. Moreover, in sample 2, a significant interaction was also found in relation to negative PEs. Our study partially replicates previous findings and suggests that some individuals are more prone to develop PEs following childhood trauma because of a complex combination of multiple factors. Further studies including genetic, environmental and epigenetic factors may provide insights in this field.

7,8-Dihydroxyflavone reverses the depressive symptoms in mouse chronic mild stress

7,8-Dihydroxyflavone (7,8-DHF) is a naturally-occurring flavone which possesses good bioavailability. Due to its ability to cross the blood-brain barrier, previous studies have demonstrated that 7,8-DHF was a potent tropomyosin-related kinase B (TrkB) agonist, and produced antidepressant-like effects in mouse forced swimming test and tail suspension test. However, it has not been evaluated in chronic mild stress (CMS), a classical depression model modulating the processes of major depression in human. In the present study, we not only evaluated the depressive-like behaviors, but also measured the key proteins of TrkB signaling in mice exposed to CMS. Our results firstly found that long term but not single injection of 7,8-DHF restored the depressive-like behaviors in sucrose preference test and novelty suppressed feeding test. In addition, 7,8-DHF not only increased TrkB phosphorylation and brain-derived neurotrophic factor (BDNF) levels, but also activated the expression of TrkB downstream synaptic proteins such as PSD95 and synaptophysin. Furthermore, the TrkB antagonist K252a blocked the antidepressant-like effects of 7,8-DHF. In summary, the present results demonstrated that chronic 7,8-DHF treatment exerted significant antidepressant-like effects, which were likely attributed to regulating TrkB signaling and thus promoting synaptic protein expression.

Harsh Parenting and Serotonin Transporter and BDNF Val66Met Polymorphisms as Predictors of Adolescent Depressive Symptoms

Depressive symptoms are prevalent and rise during adolescence. The present study is a prospective investigation of environmental and genetic factors that contribute to the growth in depressive symptoms and the frequency of heightened symptoms during adolescence. Participants included 206 mother-father-adolescent triads (M age at Time 1 = 13.06 years, SD = .51, 52% female). Harsh parenting was observationally assessed during a family conflict paradigm. DNA was extracted from saliva samples and genotyped for the 5-HTTLPR and BDNF Val66Met polymorphisms. Adolescents provide self-reports of depressive symptoms annually across early adolescence. The results reveal Gene × Environment interactions as predictors of adolescent depressive symptom trajectories in the context of harsh parenting as an environmental risk factor. A BDNF Val66Met × Harsh Parenting interaction predicted the rise in depressive symptoms across a 3-year period, whereas a 5-HTTLPR × Harsh Parenting interaction predicted greater frequency in elevated depressive symptoms. The findings highlight the importance of unique genetic and environmental influences in the development and course of heightened depressive symptoms during adolescence.

RDoC and translational perspectives on the genetics of trauma-related psychiatric disorders

Individuals with a history of child abuse are at high risk for depression, anxiety disorders, aggressive behavior, and substance use problems. The goal of this paper is to review studies of the genetics of these stress-related psychiatric disorders. An informative subset of studies that examined candidate gene by environment (GxE) predictors of these psychiatric problems in individuals maltreated as children is reviewed, together with extant genome wide association studies (GWAS). Emerging findings on epigenetic changes associated with adverse early experiences are also reviewed. Meta-analytic support and replicated findings are evident for several genetic risk factors; however, extant research suggests the effects are pleiotropic. Genetic factors are not associated with distinct psychiatric disorders, but rather diverse clinical phenotypes. Research also suggests adverse early life experiences are associated with changes in gene expression of multiple known candidate genes, genes involved in DNA transcription and translation, and genes necessary for brain circuitry development, with changes in gene expression reported in key brain structures implicated in the pathophysiology of psychiatric and substance use disorders. The finding of pleiotropy highlights the value of using the Research Domain Criteria (RDoC) framework in future studies of the genetics of stress-related psychiatric disorders, and not trying simply to link genes to multifaceted clinical syndromes, but to more limited phenotypes that map onto distinct neural circuits. Emerging work in the field of epigenetics also suggests that translational studies that integrate numerous unbiased genome-wide approaches will help to further unravel the genetics of stress-related psychiatric disorders.

Resilience Factors in Women with Severe Early-Life Maltreatment

INTRODUCTION

Early-life maltreatment (ELM) has long-lasting negative consequences and is the most important general risk factor for mental disorders. Nevertheless, a number of maltreated children grow up to become healthy adults and have therefore been called 'resilient'. The aim of the current study is to investigate 'resilience factors' in the context of severe ELM.

METHOD

The study was part of the large multicenter project Understanding and Breaking the Intergenerational Cycle of Abuse (UBICA). A total of 89 women were examined, 33 with ELM and at least one lifetime mental disorder (nonresilient), 19 with ELM but without lifetime mental disorders (resilient), and 37 without ELM and without lifetime mental disorders (controls). ELM and other circumstances before the age of 18 years were assessed with the Childhood Experience of Care and Abuse (CECA) Interview. Additional relevant person and situation factors were measured with the Structured Clinical Interview for Mental Disorders (SCID-I), International Personality Disorder Examination (IPDE), Difficulties in Emotion Regulation Scale (DERS), Vulnerable Attachment Style Questionnaire (VASQ), Barratt Impulsiveness Scale (BIS), NEO Five-Factor Inventory (NEO-FFI), and Multiple-Choice Vocabulary Intelligence Test (MWT-B). Factor analyses and paired t tests were performed to identify those variables which differentiate best between the three groups. In addition, a discriminant analysis was conducted to detect the accuracy of assigning women to their specific group.

RESULTS

The factor analyses revealed 10 resilience factors based on which we could correctly assign 80% of the women to their group in the discriminant analysis. t tests of factor scores showed that resilient and nonresilient maltreated women mainly differed in current individual attributes (e.g. impulsivity, attachment style), while resilient and nonresilient maltreated women differed from controls in both their current individual attributes and their view of their situation as a child.

CONCLUSION

The 4 variables neuroticism, extraversion, vulnerable attachment, and perceived loneliness during childhood were identified as most important in differentiating all three examined groups. Therefore, prevention and intervention programs focusing on the individual's development of secure attachment and social competence may be of particular importance in the context of ELM.