BDNFVal66Met polymorphism moderates the link between child maltreatment and reappraisal ability

Individuals being high in their sensitivity to the environment: Are sensitive period changes in play?

All individuals on planet earth are sensitive to the environment, but some more than others. These individual differences in sensitivity to environments are seen across many animal species including humans, and can influence personalities as well as vulnerability and resilience to mental disorders. Yet, little is known about the underlying brain mechanisms. Key genes that contribute to individual differences in environmental sensitivity are the serotonin transporter, dopamine D4 receptor and brain-derived neurotrophic factor genes. By synthesizing neurodevelopmental findings of these genetic factors, and discussing them through the lens of mechanisms related to sensitive periods, which are phases of heightened neuronal plasticity during which a certain network is being finetuned by experiences, we propose that these genetic factors delay but extend postnatal sensitive periods. This may explain why sensitive individuals show behavioral features that are characteristic of a young brain state at the level of sensory information processing, such as reduced filtering or blockade of irrelevant information, resulting in a sensory processing system that 'keeps all options open'.

Child maltreatment and resilience in adulthood: a protocol for a systematic review and meta-analysis

Background: Although child maltreatment (CM) has been linked to health problems and poor psychosocial functioning, not all individuals exposed to CM develop or experience negative consequences later in life. This suggests that some individuals show resilience after being exposed to CM. However, conclusions have been limited by inconsistent findings across different CM subtypes and resilience domains.Objective: To develop a protocol for conducting a systematic review and meta-analysis to quantify associations between CM (overall and its subtypes) and resilience (global and its multiple domains) in adulthood, and to examine moderators and mediators of these associations.Method: PubMed, PsycINFO, Embase, Scopus, and Web of Science will be searched to identify relevant studies on the association between CM (exposure) and resilience (outcome) in adults (≥ 18 years). Data will be screened and extracted by at least two independent reviewers. The methodological quality of the included studies will be independently assessed with a modified version of the Newcastle-Ottawa Scale (NOS). If deemed viable, a meta-analysis will be conducted using a random effects model. Heterogeneity of evidence will be estimated with the I2 statistic, and publication bias will be assessed. The effects of potential moderators (e.g. timing and severity of CM, age, sex, family cohesion, socio-economic status, country/region) will be analysed using meta-regression and subgroup analyses, and meta-analytical structural equation modelling will be employed to synthesise indirect mediation effects. Candidate moderators and mediators (e.g. genetic factors, brain functioning, attachment style, personality traits, physical activity, and social support) will be also examined qualitatively.Conclusions: This protocol will facilitate a systematic review and meta-analysis that has the potential to enhance our knowledge about the association between CM exposure in early life and resilience in adulthood. Understanding associations and underlying mechanisms between CM and resilience is potentially important in informing prevention and interventions to sustain health and improve outcomes among adults with a history of CM.PROSPERO registration: CRD42023394120.

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.

Emotion regulation as mediator between childhood adversity and psychopathology: A meta-analysis

Childhood adversity is a major risk factor for multiple forms of psychopathology, and recent efforts have focused on understanding the underlying psychological mechanisms. One outstanding candidate is emotion regulation, which has been associated with both childhood adversity, and psychopathology. Based on the available evidence, the present meta-analysis set out to investigate the mechanistic involvement of emotion regulation in the relation between childhood adversity and psychopathology. Systematic searches in three databases (PubMed; PsycINFO; Web of Science) identified 215 eligible studies. Using meta-analytic structural equation modeling, we fitted a partial mediation model to the available data across studies, in which childhood adversity was related to psychopathology both directly and through emotion regulation. Multiple emotion regulation dimensions were analyzed, including emotion regulation difficulties and the habitual use of rumination, distraction, reappraisal, and suppression. Measures of psychopathology included a wide range of internalizing and externalizing symptoms in both clinical and non-clinical samples. The results indicated that childhood adversity was positively associated with emotion regulation difficulties, as well as with the habitual use of rumination and suppression. In turn, these measures of emotion regulation were positively associated with psychopathology. Habitual reappraisal use showed negative relations with both childhood adversity and psychopathology. All these emotion regulation measures were supported as mediators in the relation between childhood adversity and psychopathology. In contrast, distraction was not related to childhood adversity or psychopathology, and its mediator role was not supported. These results suggest that altered emotion regulation is a consistent marker of childhood adversity and contributes to risk of psychopathology.

Effects of childhood trauma experience and BDNF Val66Met polymorphism on brain plasticity relate to emotion regulation

Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism may modulate the link between childhood trauma experience and psychopathology by altering trophic signaling on neuroplasticity. However, few multimodal magnetic resonance imaging (MRI) researches have investigated this gene-environment interaction on both structural and functional plasticity, thereby advancing knowledge about the etiology, prevention, and customized therapeutic directions of mental disease in individuals with childhood trauma experience. We recruited a large non-clinical sample of young adults that completed Childhood Trauma Questionnaire (CTQ), behavioral scores, multimodal MRI scans, and genotyping. Morphometric similarity network (MSN) and independent component analysis were adopted to quantify brain structural and functional changes. Gene-environment-brain-behavior relationships were identified by multiple regression and mediation effect analysis. CTQ score was positively associated with depression and anxiety scores. We found interactions on MSN in sensorimotor, temporal, and orbitofrontal cortex. For intra-network connectivity, significant interaction was noted in clusters within sensorimotor network. For inter-network connectivity, connectivity between dorsal attention network and salience network showed an interactive effect. For mean connectivity strength of each network, we found a main effect of CTQ score on self-reference network that was an outstanding mediator supporting the relationship between CTQ score and anxiety. Our findings demonstrate that childhood trauma and the BDNF Val66Met polymorphism are associated with brain plasticity involving emotion regulation, structurally and functionally, which may contribute to understanding psychotic mechanisms and predicting differential susceptibility. Imaging genetics may be useful as biomarkers to provide early assessment and guide cognitive interventions to avoid or decrease the risk of developing psychopathology.

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.