Childhood emotional environment and self-injurious behaviors: the moderating role of the BDNF Val66Met polymorphism

Positive or negative environmental modulations on human brain development: the morpho-functional outcomes of music training or stress

In the last couple of decades, the study of human living brain has benefitted of neuroimaging and non-invasive electrophysiological techniques, which are particularly valuable during development. A number of studies allowed to trace the usual stages leading from pregnancy to adult age, and relate them to functional and behavioral measurements. It was also possible to explore the effects of some interventions, behavioral or not, showing that the commonly followed pathway to adulthood may be steered by external interventions. These events may result in behavioral modifications but also in structural changes, in some cases limiting plasticity or extending/modifying critical periods. In this review, we outline the healthy human brain development in the absence of major issues or diseases. Then, the effects of negative (different stressors) and positive (music training) environmental stimuli on brain and behavioral development is depicted. Hence, it may be concluded that the typical development follows a course strictly dependent from environmental inputs, and that external intervention can be designed to positively counteract negative influences, particularly at young ages. We also focus on the social aspect of development, which starts in utero and continues after birth by building social relationships. This poses a great responsibility in handling children education and healthcare politics, pointing to social accountability for the responsible development of each child.

Potential mechanisms of non-suicidal self-injury (NSSI) in major depressive disorder: a systematic review

Background

Non-suicidal self-injury (NSSI) is a frequent and prominent phenomenon in major depressive disorder (MDD). Even though its prevalence and risk factors are relatively well understood, the potential mechanisms of NSSI in MDD remain elusive.

Aims

To review present evidence related to the potential mechanisms of NSSI in MDD.

Methods

According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, articles for this systematic review were searched on Medline (through PubMed), Embase (through Elsevier), PsycINFO (through OVID) and Web of Science databases for English articles, as well as China National Knowledge Infrastructure (CNKI), SinoMed, Wanfang Data, and the Chongqing VIP Chinese Science and Technology Periodical (VIP) Databases for Chinese articles published from the date of inception to 2 August 2022. Two researchers (BW, HZ) independently screened studies based on inclusion and exclusion criteria and assessed their quality.

Results

A total of 25 157 studies were searched. Only 25 of them were ultimately included, containing 3336 subjects (1535 patients with MDD and NSSI, 1403 patients with MDD without NSSI and 398 HCs). Included studies were divided into 6 categories: psychosocial factors (11 studies), neuroimaging (8 studies), stress and hypothalamic-pituitary-adrenal (HPA) axis (2 studies), pain perception (1 study), electroencephalogram (EEG) (2 studies) and epigenetics (1 study).

Conclusions

This systematic review indicates that patients with MDD and NSSI might have specific psychosocial factors, aberrant brain functions and neurochemical metabolisms, HPA axis dysfunctions, abnormal pain perceptions and epigenetic alterations.

Risk factors, theoretical models, and biological mechanisms of nonsuicidal self-injury: a brief review

Nonsuicidal self-injury (NSSI) refers to the direct, deliberate infliction of harm to one's body tissue without the intention to die. The prevalence of NSSI has increased significantly globally in recent years and has become an important public health problem affecting the health of people, especially adolescents. The occurrence of NSSI in adolescents is the result of the interaction of different factors. Many scholars have proposed various theoretical models to explain the mechanism of NSSI behavior based on previous research on the influencing factors of NSSI. Moreover, advances have been made in genetic and neuroimaging mechanisms related to NSSI. Understanding the genetic and neuroimaging mechanisms of NSSI is important for both describing and treating the disorder. This literature review discusses the progress made on the risk factors, theoretical models, and biological mechanisms of NSSI.

Risk and Protective Factors for Childhood Physical Abuse and Suicidal Ideation: The Effect of Brain-Derived Neurotrophic Factor Polymorphism and Social Support

OBJECTIVE

This study aimed to explore the relationship between childhood physical abuse and suicidal ideation considering the effects of genetic and environmental factors in patients with post-traumatic stress disorder (PTSD) by focusing on brain-derived neurotrophic factor (BDNF) polymorphism and social support, respectively.

METHODS

One-hundred fourteen patients with PTSD and 94 healthy controls (HCs) were genotyped with respect to BDNF Val66Met polymorphism. All participants underwent psychological assessments. The hierarchical regression analysis and the simple slope analysis were conducted.

RESULTS

As for patients with PTSD, the moderation effect of BDNF polymorphism was significant but not for social support. Specifically, the BDNF Val/Val genotype worked as a risk factor and strengthens the relationship between childhood physical abuse and suicidal ideation. As for the HCs, the significant moderation effect was found only in social support, but not for BDNF polymorphism. The relationship between childhood physical abuse and suicidal ideation was weakened for the HCs with high social support.

CONCLUSION

This study demonstrated a significant BDNF genetic vulnerability for suicide in patients with PTSD who experienced childhood physical abuse. Our results suggested that social support provided a mitigating effect on the relationship between childhood physical abuse and suicidal ideation only in the HCs.

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.

Forensic Value of Genetic Variants Associated with Anti-Social Behavior

Insanity defense is sometimes invoked in criminal cases, and its demonstration is usually based on a multifactorial contribution of behavioural, clinical, and neurological elements. Neuroradiological evidence of structural alterations in cerebral areas that involve decision-making and moral reasoning is often accepted as a useful tool in these evaluations. On the other hand, the genetic predisposition to anti-social behavior is still controversial. In this paper, we describe two cases of violent crimes committed by young carriers of genetic variants associated with personality disorder; both the defendants claimed to be insane at the time of the crime. We discuss these cases and review the scientific literature regarding the relationship between legal incapacity/predisposition to criminal behavior and genetic mutations. In conclusion, despite some genetic variants being able to influence several cognitive processes (like moral judgement and impulse control), there is currently no evidence that carriers of these mutations are, per se, incapable of intentionally committing crimes.

Harsh parenting and non-suicidal self-injury in adolescence: the mediating effect of depressive symptoms and the moderating effect of the COMT Val158Met polymorphism

BACKGROUND

Previous studies have suggested that negative parenting environments, especially harsh parenting, are a specific risk factor for non-suicidal self-injury (NSSI). However, the potential mechanism between harsh parenting and NSSI has not been explored. Based on the experiential avoidance model and empirical research, we aimed to examine whether depressive symptoms are a mediator between harsh parenting and NSSI. Moreover, the catechol-O-methyltransferase (COMT) Val158Met polymorphism related to depressive symptoms may also exert a moderating effect on NSSI; thus, the interaction between harsh parenting and COMT was also considered in our study.

METHODS

A total of 373 junior high school students were recruited for the study by using a longitudinal design. The adolescents answered self-report questionnaires and provided saliva samples for DNA genotyping.

RESULTS

The results revealed that harsh parenting was positively associated with NSSI after 24 months, and this association was mediated by depressive symptoms. Moreover, the moderating role of COMT in the direct and indirect effects of harsh parenting on NSSI was observed only among adolescents with two Val alleles and the relationship was not significant for Met carriers.

CONCLUSIONS

Genetic variations of COMT Val158Met may be a critical candidate in understanding the development of depression and NSSI. We conclude that Val homozygotes of the COMT Val158Met polymorphism play a role in susceptibility to both depressive symptoms and NSSI.

The Effects of Childhood Maltreatment on Non-Suicidal Self-Injury in Male Adolescents: The Moderating Roles of the Monoamine Oxidase A (MAOA) Gene and the Catechol-O-Methyltransferase (COMT) Gene

(1) Background: Numerous studies suggest strong associations between childhood maltreatment and nonsuicidal self-injury (NSSI); this is also true for the roles of dopaminergic genes in the etiology of some psychopathologies related to NSSI. Investigating the interactions of environments and genes is important in order to better understand the etiology of NSSI. (2) Methods: Within a sample of 269 Chinese male adolescents (Mage = 14.72, SD = 0.92), childhood maltreatment and NSSI were evaluated, and saliva samples were collected for MAOA T941G and COMT Val158Met polymorphism analyses. (3) Results: The results revealed no primary effects attributable to MAOA T941G and COMT Val158Met polymorphism on NSSI. However, there was a significant three-way interaction between MAOA, COMT, and child abuse (β = −0.34, p < 0.01) in adolescent NSSI. Except for carriers of the T allele of MAOA and the Met allele of COMT, all studied male adolescents displayed higher NSSI scores when exposed to a higher level of child abuse. A similar three-way interaction was not observed in the case of child neglect. (4) Conclusions: The results indicate that the MAOA gene and COMT gene play moderating roles in the association between child abuse and NSSI of male adolescents and suggest the polygenic underpinnings of NSSI.

[Pain perception and nonsuicidal self-injurious behavior]

This review focuses on studies of pain threshold and tolerance in individuals with nonsuicidal self-injurious (NSSI) behavior. The data on methods of pain sensitivity studies are presented, with issues in animal modeling of NSSI discussed separately. The results of neuroimaging studies on pain sensitivity in individuals with NSSI are described, along with contribution of genetic factors, psychological variables, and disturbances in opioid and hypothalamic-pituitary-adrenal systems. A critical methodological analysis of the studies on pain sensitivity in individuals with NSSI was performed.

Modeling endophenotypes of suicidal behavior in animals

Suicide is a major public health concern. One of the common contributors to the increased risk for suicide is the genetic constitution of individuals, which determines certain endophenotypic traits used as quantifiable measure of neurobiological functions. Therefore, a logical deconstruction of the originating endophenotypes associated with suicidal risk could provide a better understanding of this complex disorder. In this regard, non-human animals can be a useful resource to test endophenotypes of suicidal behavior and the neurobiology underlying these endophenotypes. In this review, we have focused on the neurobiological abnormalities, primarily genetic and epigenetic abnormalities, associated with suicidal behavior and the scope of their modeling in animals. This can substantially advance the current understanding of suicidal behavior manifested with certain trait-based endophenotypes and may provide an opportunity to test novel hypotheses as well as aid in the development of treatment opportunities and risk assessment.

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.

SERT and BDNF polymorphisms interplay on neuroticism in borderline personality disorder

Objective

Genetic factors underlying different personality traits are not entirely understood, particularly how genes interact to modulate their effect. We studied 76 patients diagnosed with borderline personality disorder (BPD), characterized by extreme levels of personality traits, especially neuroticism (N), in which we genotyped two polymorphisms, the 5HTTLPR of the Serotonin transporter (SERT) gene, and the Val66Met of the Brain-derived neurotrophic factor (BDNF) gene.

Results

We found an association with SERT, where S-allele carriers had significantly higher levels of N than L-homozygous. Furthermore, we found that the protective effect of L-homozygosity is only evident on A-allele carriers of the BDNF Val66Met polymorphism. Genetic constitution in SERT and BDNF seems to be important in neuroticism, the most relevant personality trait on BPD.

An examination of genes, stress and suicidal behavior in two First Nations communities: The role of the brain-derived neurotropic factor gene

Suicide claims over 800,000 lives each year worldwide. Suicide rates in indigenous populations in Canada are about double that of the national average, making it a serious public health issue. Numerous factors are involved in suicide risk, including genetic factors, as well as various psychosocial stressors, such as historical experience with the Indian Residential School system for Indigenous populations, as well as protective variables such as social support. Here, we report the first genetic study of suicidal behaviors that includes multiple measures of stress and social supports. We investigated the role of the functional Val66Met marker (rs6265) in the Brain-Derived Neurotropic Factor (BDNF) gene in suicidal ideation and suicide attempt in a First Nations community sample (N = 278). We did not find a significant association between the BDNF rs6265 marker and suicidal behaviors. We found childhood adversities, recent life stress, chronic stress, perceived stress, difficulties, and hazardous alcohol use to be associated with both suicidal ideation and suicide attempt. Thus, while additional studies with larger samples are required to elucidate the genetic component of suicide, addressing environmental stressors may be important for suicide prevention.

Oxytocin-related single-nucleotide polymorphisms, family environment, and psychopathic traits

Multiple studies have linked oxytocin to social behavior and affiliation-attachment. This research would suggest that oxytocin function may relate to the absence of loving kindness and empathy in psychopathy. The current study examined the associations between 3 oxytocin-related single-nucleotide polymorphisms (SNPs), participant-reported invalidating childhood environment, and psychopathic traits in community adults, predicting that alleles associated with higher empathy in the literature would relate to lower levels of psychopathic affective traits in particular. Results showed that the rs53576 SNP on the oxytocin receptor and cumulative risk alleles across the 3 SNPs were associated with psychopathic traits, and the interaction between cumulative risk and an emotionally invalidating environment was associated especially with affective deficits of psychopathy. Although this study requires replication in larger samples, results lend support to the role of attachment-related processes in psychopathy. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Brain derived neurotrophic factor (BDNF) and suicidal behavior: A review of studies from Asian countries

The biological basis of suicide and suicidal behavior is actively researched. Recently, the role of Brain Derived Neurotropic Factor (BDNF) in suicidal behavior has gained attention and significant results are observed. In this review, we aimed to focus on the studies from Asian countries that have explored the role of BDNF and suicidal behavior. The review highlights the findings from these studies and discusses the possible avenues that should be explored in future studies from Asian countries to understand more on suicidal behavior and possible prevention.

Childhood maltreatment and non-suicidal self-injury: a systematic review and meta-analysis

BACKGROUND

Non-suicidal self-injury is being increasingly recognised as a prominent public health concern. Identification of early and modifiable risk factors is necessary to advance the screening and intervention efforts, particularly early detection of at-risk individuals. We aimed to examine childhood maltreatment, including its specific subtypes, in relation to non-suicidal self-injury.

METHODS

We did a comprehensive meta-analysis of childhood maltreatment (overall, sexual abuse, physical abuse and neglect, and emotional abuse and neglect) in association with non-suicidal self-injury. We also provided a qualitative review of mediators and moderators of this association. We identified relevant articles published from inception to Sept 25, 2017, through a systematic search of Embase, MEDLINE, and PsycINFO. We extracted continuous and categorical data and assessed for potential moderators using ten study characteristics. We generated random-effects models for analysis and evaluated for publication bias.

FINDINGS

We identified 71 publications that met eligibility criteria. Overall childhood maltreatment was associated with non-suicidal self-injury (odds ratio 3·42, 95% CI 2·74-4·26), and effect sizes for maltreatment subtypes ranged from 1·84 (1·45-2·34) for childhood emotional neglect to 3·03 (2·56-3·54) for childhood emotional abuse. Publication bias was not evident, except in the case of childhood emotional neglect. Across multiple maltreatment subtypes, we found stronger associations with non-suicidal self-injury in non-clinical samples.

INTERPRETATION

With the exception of childhood emotional neglect, childhood maltreatment and its subtypes are associated with non-suicidal self-injury. Screening of childhood maltreatment history in non-suicidal self-injury risk assessments might hold particular value in community settings, and increased attention to childhood emotional abuse is warranted.

FUNDING

National Institute of Mental Health.

Do serum BDNF levels vary in self-harm behavior among adolescents and are they correlated with traumatic experiences?

The aim of this study was to compare serum brain-derived neurotrophic factor (BDNF) levels between adolescents that harm themselves, those that receive psychiatric treatment but do not harm themselves, healthy adolescents, and childhood traumas and to investigate the relationship between traumatic experiences and serum BDNF levels. The cases were divided into two groups of 40 adolescents exhibiting self-harm behavior (self-harm/diagnosed group) and 30 adolescents receiving psychiatric treatment but not exhibiting self-harm behaviors (non self-harm/diagnosed group). The control group (healthy control group) consisted of 35 healthy adolescents with no psychiatric disorders or self-harm behaviors. The adolescents were asked to fill in the Inventory of Statements About Self Injury (ISAS) and Childhood Trauma Questionnaire (CTQ). For BDNF measurement, blood samples were taken from the cases and controls. The serum BDNF level of self-harming adolescents who used the self-cutting method was significantly lower than that of other groups, and serum BDNF levels decreased with the increase in the emotional neglect and abuse severity of self-harming adolescents during childhood. In our study, serum BDNF levels decreased with the increase in emotional abuse in self-harming adolescents. This finding may indicate that neuroplasticity can be affected by a negative emotional environment during the early period.

Neuropathology of suicide: recent findings and future directions

Suicide is a major public health concern and a leading cause of death in most societies. Suicidal behaviour is complex and heterogeneous, likely resulting from several causes. It associates with multiple factors, including psychopathology, personality traits, early-life adversity and stressful life events, among others. Over the past decades, studies in fields ranging from neuroanatomy, genetics and molecular psychiatry have led to a model whereby behavioural dysregulation, including suicidal behaviour (SB), develops as a function of biological adaptations in key brain systems. More recently, the unravelling of the unique epigenetic processes that occur in the brain has opened promising avenues in suicide research. The present review explores the various facets of the current knowledge on suicidality and discusses how the rapidly evolving field of neurobehavioural epigenetics may fuel our ability to understand, and potentially prevent, SB.

Biomarkers of Suicide Attempt Behavior: Towards a Biological Model of Risk

PURPOSE OF REVIEW

The rising suicide rate in the USA will not be reversed without improved risk assessment and prevention practices. To date, the best method for clinicians to assess a patient's risk for suicide is screening for past suicide attempts in the patient and their family. However, neuroimaging, genomic, and biochemical studies have generated a body of findings that allow description of an initial heuristic biological model for suicidal behavior that may have predictive value.

RECENT FINDINGS

We review studies from the past 3 years examining potential biological predictors of suicide attempt behavior. We divide findings into two major categories: (1) structural and functional brain imaging findings and (2) biochemical and genomic findings encompassing several systems, including major neurotransmitters (serotonin, catecholamines, GABA, and glutamate), the hypothalamic pituitary adrenal (HPA) axis, the inflammasome, lipids, and neuroplasticity. The biomarkers that appear promising for assessing suicide risk in clinical settings include indices of serotonergic function, inflammation, neuronal plasticity, and lipids.

BDNF Val66Met, stress, and positive mothering: Differential susceptibility model of adolescent trait anxiety

Etiological research has indicated the gene-environment interaction (G × E) on adolescent anxiety. This study aimed to examine how the BDNF Val66Met polymorphism interacted with stressful life events and positive mothering to influence youth trait anxiety. The study sample included 780 community adolescents of Chinese Han ethnicity (M = 13.6, 51.3% females). Participants' trait anxiety, exposure to stressful life events, and mother's warmth-reasoning were assessed by self-reported questionnaires. We found that BDNF Val66Met polymorphism significantly moderated the influences of stressful life events and mother's warmth-reasoning on adolescent anxiety. The influences were significantly greater in adolescents carrying one or two Val allele than those with Met/Met genotype. Moreover, the G × E interactions were more consistent with the differential susceptibility than the diathesis-stress model. Adolescents carrying Val allele who were more susceptible to adversity were also more likely to benefit from supportive experiences. These findings provide novel evidence for the role of BDNF Val66Met as a genetic susceptibility modulating the influences of stressful life events and mother's warmth-reasoning on adolescent anxiety. We speculate that BDNF Val66Met may moderate anxious youths' responses to mindfulness-based stress reduction program and family-based treatment targeting the enhancement of positive parenting.

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

BACKGROUND

There is limited evidence for a moderating role of both serotonin transporter (SERT) and brain-derived neurotrophic factor (BDNF) genes on the risk for major depression (MD) developing after childhood maltreatment. However, research on this topic remains inconclusive, and there is a lack of data from longitudinal studies with large and representative population samples. Our study aimed to clarify whether, in the presence of previous childhood maltreatment, individuals carrying low functional alleles for both SERT 5-HTTLPR and BDNF Val66Met polymorphisms had a higher risk for MD.

METHODS

We explored 2- and 3-way gene (SERT and BDNF) × environment (childhood maltreatment) interactions in a large sample of Spanish adults who were followed up over a 3-year period and assessed in person for both DSM-IV MD and exposure to childhood maltreatment.

RESULTS

Our study included 2679 participants. Those with both the 5-HTTLPR s allele and the BDNF Met allele showed the highest risk of MD if they had previously experienced emotional (z = 2.08, p = 0.037), sexual (z = 2.19, p = 0.029) or any kind of childhood abuse (z = 2.37, p = 0.018). These 3-way interactions remained significant regardless of whether the 5-HTTLPR triallelic or the 5-HTTLPR biallelic polymorphisms were included in the analyses.

LIMITATIONS

Retrospective assessment of childhood maltreatment may have resulted in a moderate degree of recall bias.

CONCLUSION

Our results confirm that the risk of depression conferred by childhood maltreatment is modified by variation at both SERT and BDNF genes.

Dysfunctional Attitudes and Affective Responses to Daily Stressors: Separating Cognitive, Genetic, and Clinical Influences on Stress Reactivity

Despite decades of research examining diathesis-stress models of emotional disorders, it remains unclear whether dysfunctional attitudes interact with stressful experiences to shape affect on a daily basis and, if so, how clinical and genetic factors influence these associations. To address these issues, we conducted a multi-level daily diary study that examined how dysfunctional attitudes and stressful events relate to daily fluctuations in negative and positive affect in 104 young adults. Given evidence that clinical and genetic factors underlie stress sensitivity, we also examined how daily affect is influenced by internalizing and externalizing symptoms and brain-derived neurotrophic factor (BDNF) genotype, which have been shown to influence neural, endocrine, and affective responses to stress. In multivariate models, internalizing symptoms and BDNF Val66Met genotype independently predicted heightened negative affect on stressful days, but dysfunctional attitudes did not. Specifically, the BDNF Met allele and elevated baseline internalizing symptomatology predicted greater increases in negative affect in stressful circumstances. These data are the first to demonstrate that BDNF genotype and stress are jointly associated with daily fluctuations in negative affect, and they challenge the assumption that maladaptive beliefs play a strong independent role in determining affective responses to everyday stressors. The results may thus inform the development of new multi-level theories of psychopathology and guide future research on predictors of affective lability.

Use of the cross-translational model to study self-injurious behavior in human and nonhuman primates

Nonsuicidal self-injurious behavior occurs in the general human population, particularly among teenagers and young adults. Some rhesus macaques also develop self-injurious behavior (SIB) as adolescents or young adults. In both of these cases, the development of harmful behaviors is idiopathic, only coming to the attention of physicians or veterinarians after the disorder is established. Thus, a combination of retrospective, statistical, and empirical procedures are used to understand this disorder. Here, we identify concordances between macaques and humans across five different levels of analysis-(1) form and prevalence, (2) etiology, (3) triggering events, (4) function/maintenance, and (5) therapeutic intervention-and show the value of the cross-translational model (macaques to humans and humans to macaques) in understanding this phenomenon. Substantial concordance is present with respect to the range of severity, the presence of early life stress exposure, and emotional dysregulation. In the macaque model, additional information is available on the hypothalamic-pituitary-adrenal axis stress response system, possible genetic involvement, and the immediate contextual situations that appear to trigger or exacerbate SIB episodes. In contrast, considerably more information is available from human studies on the effectiveness of various treatment regimens. Veterinarians have drawn on this information to explore these therapeutic interventions in monkeys. We expect that models of SIB will continue to have cross-translational impact as scientists and practitioners move from preclinical to clinical research and treatment.