Childhood adversity, depression, age and gender effects on white matter microstructure: a DTI study

Understanding the nature and dynamics of self-affirmation in non-depressed and subclinically depressed Indian adults: a thematic analysis

BACKGROUND

Self-affirmation, a crucial concept that promotes self-esteem and individual development amidst life challenges, has proven therapeutic, preventative, and enhancing benefits. However, there is limited understanding regarding its frequency among individuals experiencing subclinical depression. This research aimed to understand the dynamics of self-affirmation, threats, and self-resources in both healthy (non-depressed) and subclinically depressed Indian adults.

METHODS

Using a qualitative research design, forty-three individuals aged 20-30 years (18 healthy, 25 subclinically depressed individuals) were selected based on depression measurement. The data were collected through a semistructured interview. The interviews were audiotaped, transcribed verbatim and analysed using the thematic analysis method.

RESULTS

Five themes were identified for subclinically depressed: social and relational threats, the tendency to magnify threats, negative cognitions and thoughts, denial/avoidance of threats, and poor awareness of self-resources. Five themes were also identified for healthy adults: explicit awareness of threats, common humanity, early responses to threats, adversity as an opportunity and easy availability of positive cognitions. Thus, the two groups differed significantly in their type, nature, and genesis of self-affirmation. For subclinically depressed, the major threats were related to health, financial conditions, employment, and relationships. These threats were positively and adaptively present in healthy adults. The subclinically depressed participants suffered from maladaptive tendencies and insufficient self-resources, while the healthy participants used positive self-resources and positive cognitions in dealing with the threats.

CONCLUSIONS

This study highlights the significant differences in self-affirmation processes between subclinically depressed and healthy adults. This finding supports the theoretical understanding that subclinical depression is associated with maladaptive cognitive patterns and a lack of self-resources. These findings underscore the importance of cognitive-behavioural frameworks that emphasize the role of positive self-affirmation and self-resources in mental health and highlight the need for targeted interventions that can strengthen these domains in subclinically depressed individuals. Therapeutic interventions for subclinical depression should focus on improving self-affirmation practices, increasing awareness of self-resources, and attenuating negative cognitive tendencies. Practitioners should consider integrating strategies that promote positive cognitions and proactive threat management. Additionally, preventative mental health programs could benefit from incorporating modules that strengthen self-affirmation and self-resource awareness of one's resources to build resilience in the general population, particularly young adults.

Atypical brain structural connectivity and social cognition in childhood maltreatment and peer victimisation

BACKGROUND

Childhood maltreatment (CM) is associated with neurobiological aberrations and atypical social cognition. Few studies have examined the neural effects of another common early-life interpersonal stressor, namely peer victimisation (PV). This study examines the associations between tract aberrations and childhood interpersonal stress from caregivers (CM) and peers (PV), and explores how the observed tract alterations are in turn related to affective theory of mind (ToM).

METHODS

Data from 107 age-and gender-matched youths (34 CM [age = 19.9 ± 1.68; 36%male], 35 PV [age = 19.9 ± 1.65; 43%male], 38 comparison subjects [age = 20.0 ± 1.66; 42%male] were analysed using tractography and whole-brain tract-based spatial statistics (TBSS).

RESULTS

At the whole-brain level using TBSS, the CM group had higher fractional anisotropy (FA) than the PV and comparison groups in a cluster of predominantly limbic and corpus callosal pathways. Segmented tractography indicated the CM group had higher FA in right uncinate fasciculus compared to both groups. They also had smaller right anterior thalamic radiation (ATR) tract volume than the comparison group and higher left ATR FA than the PV group, with these metrics associated with higher emotional abuse and enhanced affective ToM within the CM group, respectively. The PV group had lower inferior fronto-occipital fasciculus FA than the other two groups, which was related to lower affective ToM within the PV group.

CONCLUSION

Findings suggest that exposure to early-life stress from caregivers and peers are differentially associated with alterations of neural pathways connecting the frontal, temporal and occipital cortices involved in cognitive and affective control, with possible links to their atypical social cognition.

Age-related changes in the healthy adult visual pathway: evidence from diffusion tensor imaging with fixel-based analysis

BACKGROUND AND PURPOSE

Fixel-based analysis (FBA) is a new method that overcomes the technical limitations of diffusion tensor imaging (DTI) by enabling the characterization of multiple fiber populations within a voxel, and provides biologically meaningful indicators. This study aimed to explore age-related changes in the visual pathway in healthy adults and to observe differences in imaging quality between data collected using different b‑values.

METHODS

In this prospective cross-sectional study, brain DTI scans which were collected with more than six uniformly distributed gradient directions and higher b‑values (up to 2000 s/mm2) than traditional DTI were performed in 72 healthy adults across the adult lifespan (20-79 years). After image preprocessing, FBA was used to process the dataset. At the same time, conventional DTI metrics were also calculated.

RESULTS

Pearson's correlation analysis showed that DTI parameters of white matter (optic nerve, optic chiasma, optic tract, and optic radiation) in the optic pathway were correlated with age. FA values were negatively correlated with age, while MD/AD/RD showed a positive correlation (P < 0.05). FBA showed that the index including FD/FC/FDC tended to decline with age (P < 0.05). Linear regression analysis showed a linear relationship between DTI metrics of the dataset collected by b‑values of 1000 and 2000 s/mm2 (P < 0.05).

CONCLUSION

FBA provides a useful method to assess age-related changes in the visual pathway, which is sensitive to diffusion. In addition, the b‑value influences DTI parameters and signal-to-noise ratio of the image.

Brain-based Sex Differences in Depression: A Systematic Review of Neuroimaging Studies

Major depressive disorder (MDD) is a common psychiatric illness with a wide range of symptoms such as mood decline, loss of interest, and feelings of guilt and worthlessness. Women develop depression more often than men, and the diagnostic criteria for depression mainly rely on female patients' symptoms. By contrast, male depression usually manifests as anger attacks, aggression, substance use, and risk-taking behaviors. Various studies have focused on the neuroimaging findings in psychiatric disorders for a better understanding of their underlying mechanisms. With this review, we aimed to summarize the existing literature on the neuroimaging findings in depression, separated by male and female subjects. A search was conducted on PubMed and Scopus for magnetic resonance imaging (MRI), functional MRI (fMRI), and diffusion tensor imaging (DTI) studies of depression. After screening the search results, 15 MRI, 12 fMRI, and 4 DTI studies were included. Sex differences were mainly reflected in the following regions: 1) total brain, hippocampus, amygdala, habenula, anterior cingulate cortex, and corpus callosum volumes, 2) frontal and temporal gyri functions, along with functions of the caudate nucleus and prefrontal cortex, and 3) frontal fasciculi and frontal projections of corpus callosum microstructural alterations. Our review faces limitations such as small sample sizes and heterogeneity in populations and modalities. But in conclusion, it reflects the possible roles of sex-based hormonal and social factors in the depression pathophysiology.

The effect of adverse childhood experiences on chronic pain and major depression in adulthood: a systematic review and meta-analysis

BACKGROUND

Adverse childhood experiences have been linked to increased multimorbidity, with physical and mental health consequences throughout life. Chronic pain is often associated with mood disorders, such as major depressive disorder (MDD); both have been linked to adverse childhood experiences. It is unclear how the effect of adverse childhood experiences on neural processing impacts on vulnerability to chronic pain, MDD, or both, and whether there are shared mechanisms. We aimed to assess evidence for central neural changes associated with adverse childhood experiences in subjects with chronic pain, MDD, or both using systematic review and meta-analysis.

METHODS

Electronic databases were systematically searched for neuroimaging studies of adverse childhood experiences, with chronic pain, MDD, or both. Two independent reviewers screened title, abstracts, and full text, and assessed quality. After extraction of neuroimaging data, activation likelihood estimate meta-analysis was performed to identify significant brain regions associated with these comorbidities.

RESULTS

Forty-nine of 2414 studies were eligible, of which 43 investigated adverse childhood experiences and MDD and six investigated adverse childhood experiences and chronic pain. None investigated adverse childhood experiences, chronic pain, and MDD together. Functional and structural brain abnormalities were identified in the superior frontal, lingual gyrus, hippocampus, insula, putamen, superior temporal, inferior temporal gyrus, and anterior cerebellum in patients with MDD exposed to adverse childhood experiences. In addition, brain function abnormalities were identified for patients with MDD or chronic pain and exposure to adverse childhood experiences in the cingulate gyrus, inferior parietal lobule, and precuneus in task-based functional MRI studies.

CONCLUSIONS

We found that adverse childhood experiences exposure can result in different functional and structural brain alterations in adults with MDD or chronic pain compared with those without adverse childhood experiences.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42021233989.

Gray and white matter abnormalities in major depressive disorder patients and its associations with childhood adversity

OBJECTIVE

Early life stress of childhood adversity (CA) may result in major depressive disorder (MDD) by sensitizing individuals to proximal stressors in life events. The neurobiological changes that underlie adult depression may result from the absence of proper care and supervision of caregivers. We aimed to find both gray and white matter abnormalities in MDD patients, who reported the experiences of CA.

METHODS

The present study examined cortical alterations in 54 patients with MDD and 167 healthy controls (HCs) using voxel-based morphology and fractional anisotropy (FA) tract-based spatial statistics (TBSS). Both patients and HCs were administered the self-questionnaire clinical scale (the Korean translation of the Childhood Trauma Questionnaire CTQK). Pearson's correlation analysis was performed to find the associations between FA and CTQK.

RESULTS

The MDD group showed a significant decrease in gray matter (GM) in the left rectus at both the cluster and peak levels after family-wise error correction. The TBSS results showed significantly reduced FA in widespread regions, including the corpus callosum (CC), superior corona radiata, cingulate gyrus, and superior longitudinal fasciculus. The CA was negatively correlated with the FA in CC and crossing pontine tract.

CONCLUSION

Our findings demonstrated GM atrophy and white matter (WM) connectivity changes in patients with MDD. The major findings of the widespread FA reduction in WM provided the evidence of brain alterations in MDD. We further propose that the WM would be vulnerable to emotional, physical, and sexual abuse in early childhood during the brain development.

The Mediating Role of Brain Structural Imaging Markers in Connecting Adverse Childhood Experiences and Psychological Resilience

The impact of adverse childhood experiences (ACEs) on brain structure has been noticed. Resilience has been considered a protective characteristic from being mentally ill; however, the link between ACEs, psychological resilience, and brain imaging remains untested. A total of 108 participants (mean age 22.92 ± 2.43 years) completed the ACEs questionnaire and the Resilience Scale for Adults (RSA), with five subscales: personal strength (RSA_ps), family cohesion (RSA_fc), social resources (RSA_sr), social competence (RSA_sc), and future structured style (RSA_fss), and Magnetic Resonance Imaging (MRI) to acquire imaging data, and the fusion-independent component analysis was employed to determine multimodal imaging components. The results showed a significantly negative association between ACE subscales and RSA_total score (ps < 0.05). The parallel mediation model showed significant indirect mediation of mean gray matter volumes in the regions of the middle frontal gyrus, superior frontal gyrus, posterior cingulate, superior temporal gyrus, middle temporal gyrus, postcentral gyrus, middle temporal gyrus, and precuneus between childhood maltreatment and RSA_sr and RSA_sc. (ps < 0.05). This study highlighted the ACEs effect on gray matter volumes in the regions of the middle frontal gyrus, superior frontal gyrus, posterior cingulate, superior temporal gyrus, middle temporal gyrus, postcentral gyrus, middle temporal gyrus, and precuneus leading to decreased psychological resilience.

Transdiagnostic role of glutamate and white matter damage in neuropsychiatric disorders: A Systematic Review

Neuropsychiatric disorders including generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SZ) have been considered distinct categories of diseases despite their overlapping characteristics and symptomatology. We aimed to provide an in-depth review elucidating the role of glutamate/Glx and white matter (WM) abnormalities in these disorders from a transdiagnostic perspective. The PubMed online database was searched for studies published between 2010 and 2021. After careful screening, 401 studies were included. The findings point to decreased levels of glutamate in the Anterior Cingulate Cortex in both SZ and BD, whereas Glx is elevated in the Hippocampus in SZ and MDD. With regard to WM abnormalities, the Corpus Callosum and superior Longitudinal Fascicle were the most consistently identified brain regions showing decreased fractional anisotropy (FA) across all the reviewed disorders, except GAD. Additionally, the Uncinate Fasciculus displayed decreased FA in all disorders, except OCD. Decreased FA was also found in the inferior Longitudinal Fasciculus, inferior Fronto-Occipital Fasciculus, Thalamic Radiation, and Corona Radiata in SZ, BD, and MDD. Decreased FA in the Fornix and Corticospinal Tract were found in BD and SZ patients. The Cingulum and Anterior Limb of Internal Capsule exhibited decreased FA in MDD and SZ patients. The results suggest a gradual increase in severity from GAD to SZ defined by the number of brain regions with WM abnormality which may be partially caused by abnormal glutamate levels. WM damage could thus be considered a potential marker of some of the main neuropsychiatric disorders.

Do Trajectories of Sensation Seeking Vary by Sex and Child Maltreatment Subtypes?

Child maltreatment and elevated sensation seeking are associated with a wide range of negative outcomes. Longitudinal data from a study of Puerto Ricans living in two sociocultural contexts were used to determine whether child maltreatment subtypes, sex, or sociocultural context relate to trajectories of sensation seeking. Participants were 2,489 individuals from the Boricua Youth Study (48.5% girls) living in New York and in Puerto Rico (PR; 5-15 years old at Wave 1). Subtypes of child maltreatment were measured using child report on the Parent-Child Conflict Tactics Scale and the Sexual Victimization Scale at Wave 1. The association between child maltreatment subtypes, sex, sociocultural context, and previously established sensation-seeking trajectories across three waves of data collection was probed using multinomial logistic regression. Girls, but not boys, who experienced neglect (adjusted odds ratio; AOR; 95% confidence interval [95% CI] = 5.33 [1.35, 21.03]), or physical abuse (AOR [95% CI] = 3.66 [1.07, 12.54]), were more likely to have an elevated sensation-seeking trajectory than a normative trajectory. For boys, none of the maltreatment subtypes were linked to the elevated sensation-seeking class. Girls exposed to verbal abuse (AOR [95% CI] = 0.33 [0.15, 0.75]) and boys exposed to physical abuse (AOR [95% CI] = 0.39 [0.16, 0.97]) were less likely to belong to the low sensation-seeking class. No significant interactions between sociocultural context (i.e., PR vs. New York) and maltreatment subtype on the development of sensation seeking were found. This research suggests sensation-seeking levels vary by experiences of childhood maltreatment, and that sex moderates the relationship between child maltreatment experiences and sensation seeking, with an association between some maltreatment subtypes and elevated sensation-seeking trajectories found in girls, but not boys. These results underline the importance of considering sex when examining how child maltreatment relates to outcomes.

Early Life Adversity and Males: Biology, Behavior, and Implications for Fathers' Parenting

Fathers have an important and unique influence on child development, but influences on fathers' parenting have been vastly understudied in the scientific literature. In particular, very little empirical research exists on the effects of early life adversity (ELA; e.g. childhood maltreatment, parental separation) on later parenting among fathers. In this review, we draw from both the human and non-human animal literature to examine the effects of ELA, specifically among males, in the following areas: 1) neurobiology and neurocognitive functioning, 2) hormones and hormone receptors, 3) gene-environment interactions and epigenetics, and 4) behavior and development. Based on these findings, we present a conceptual model to describe the biological and behavioral pathways through which exposure to ELA may influence parenting among males, with a goal of guiding future research and intervention development in this area. Empirical studies are needed to improve understanding of the relationship between ELA and father's parenting, inform the development of paternal and biparental interventions, and prevent intergenerational transmission of ELA.

Pediatric PTSD is characterized by age- and sex-related abnormalities in structural connectivity

Pediatric post-traumatic stress disorder (pPTSD) is a prevalent and pervasive form of mental illness comprising a disparate constellation of psychiatric symptoms. Emerging evidence suggests that pPTSD may be characterized by alterations in functional networks traversing the brain. Yet, little is known about pathological changes in the structural tracts underlying functional connectivity. In adults, PTSD is linked to widespread change in white matter integrity throughout the brain, yet similar studies with youth populations have yet to be conducted. Current understanding of the nature and treatment of pPTSD may be enhanced by examining alterations in white matter, while further untangling effects of age and sex. Here, we assess the microstructure of 12 major white matter tracts in a sample of well-phenotyped youth with PTSD. Measures of fractional anisotropy were derived from diffusion tensor images acquired from 82 unmediated youth (ages 8-18), of whom 39 met criteria for pPTSD. Diagnosis of pPTSD was linked to remarkable age- and sex-linked differences in the microstructure of major white matter tracts including the uncinate fasciculus, cingulum bundle, and inferior longitudinal fasciculus. In each case, youth with PTSD show an absence of increased white matter integrity with age, suggesting an altered pattern of neurodevelopment that may contribute to persistence or worsening of illness. Broadly, our results suggest abnormal white matter development in pediatric PTSD, a finding which may contribute to illness persistence, comorbidity with other disorders, and poorer prognosis across time. Critically, these findings further speak to the nature of pPTSD as a 'whole-brain' disorder.

Restoring and preserving capacity of self-affirmation for well-being in Indian adults with non-clinical depressive tendencies

BACKGROUND

Although self-affirmation has been reported to enhance well-being and other positive life outcomes in normal adults, little is known about its capacity to restore and preserve well-being in adults with depressive tendencies. The current study attempts to expound the restoring and preserving capacity of self-affirmation for well-being in Indian adults with non-clinical depressive tendencies.

PARTICIPANTS AND PROCEDURE

The study used a sequential research design. Eighty participants (22-27 years) with depressive tendencies were chosen through purposive sampling and were randomly assigned equally to the experimental and control conditions. Their depressive tendencies and well-being were measured through standard scales at three intervals: pre-intervention, post-intervention and follow-up.

RESULTS

The results revealed significant restoring and preserving capacity of self-affirmation for the well-being of the experimental group participants as compared to the control group. The main effects of conditions (experimental, control) and treatment intervals (pre, post, follow-up) were significant along with the interaction effects of conditions × treatment intervals. The significant differences in the mean well-being scores for pre-intervention, post-intervention and follow-up points of time showed the restoring and preserving capacity of self-affirmation intervention.

CONCLUSIONS

The findings showed that self-affirmation helps to restore well-being as well as preserve it after a significant gap, which is evident in higher well-being mean scores of the experimental group taken at post-intervention and follow-up intervals. The positive effects of self-affirmation on well-being may have remained active even after the cessation of the intervention due to the underlying mechanisms of enhanced self-worth, positive values, inner strengths, positive attributions and interpersonal relationships.

Opposing relationships of childhood threat and deprivation with stria terminalis white matter

While stress may be a potential mechanism by which childhood threat and deprivation influence mental health, few studies have considered specific stress‐related white matter pathways, such as the stria terminalis (ST) and medial forebrain bundle (MFB). Our goal was to examine the relationships between childhood adversity and ST and MFB structural integrity and whether these pathways may provide a link between childhood adversity and affective symptoms and disorders. Participants were young adults (n = 100) with a full distribution of maltreatment history and affective symptom severity. Threat was determined by measures of childhood abuse and repeated traumatic events. Socioeconomic deprivation (SED) was determined by a measure of childhood socioeconomic status (parental education). Participants underwent diffusion spectrum imaging. Human Connectome Project data was used to perform ST and MFB tractography; these tracts were used as ROIs to extract generalized fractional anisotropy (gFA) from each participant. Childhood threat was associated with ST gFA, such that greater threat was associated with less ST gFA. SED was also associated with ST gFA, however, conversely to threat, greater SED was associated with greater ST gFA. Additionally, threat was negatively associated with MFB gFA, and MFB gFA was negatively associated with post‐traumatic stress symptoms. Our results suggest that childhood threat and deprivation have opposing influences on ST structural integrity, providing new evidence that the context of childhood adversity may have an important influence on its neurobiological effects, even on the same structure. Further, the MFB may provide a novel link between childhood threat and affective symptoms.

White matter changes in children and adolescents with reactive attachment disorder: A diffusion tensor imaging study

Childhood maltreatment is associated with altered brain structure and function and is a major risk factor for psychopathology, including reactive attachment disorder (RAD). However, whether changes to white matter microstructural integrity are associated with RAD is unclear. We used diffusion tensor imaging (DTI) to assess group differences in fractional anisotropy (FA) in patients with RAD (n = 25; mean age = 13.2) to typically developing (TD) controls (n = 33; mean age = 13.0). To further interpret differences in FA, additional parameters such as mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) were assessed. We found that FA values in the body of corpus callosum (CC) and in the projection and thalamic pathways, including the posterior limb of the internal capsule and corona radiata (anterior, posterior, and superior), were significantly higher in the RAD than in the TD group. Additionally, RAD group showed significantly lower RD values in the body of the CC and abovementioned pathways than TD group. Our findings indicate that RAD is associated with altered structure of the CC and projection and thalamic pathways, which may play a role in emotion regulation. The aberrant development of these tracts in RAD may reflect stress-related psychophysiological responses.

Different brain profiles in children with prenatal alcohol exposure with or without early adverse exposures

Prenatal alcohol exposure (PAE) can alter brain development and impact mental health outcomes, and often occurs in conjunction with postnatal adversity (e.g., maltreatment). However, it is unclear how postnatal adverse exposures may moderate mental health and brain outcomes in children with PAE. T1‐weighted and diffusion magnetic resonance imaging were obtained from 66 participants aged 7–16 years. Twenty‐one participants had PAE and adverse postnatal exposures (PAE+), 12 had PAE without adverse postnatal exposures (PAE−), and 33 were age‐ and gender‐matched controls unexposed to either prenatal alcohol or postnatal adversity. Internalizing and externalizing mental health symptoms were assessed using the Behavioral Assessment System for Children II, Parent‐Rating Scale. ANCOVAs were used to compare mental health symptoms, limbic and prefrontal cortical volumes, and diffusion parameters of cortico‐limbic white matter tracts between groups, and to assess brain‐mental health relationships. Both PAE groups had worse externalizing behavior (higher scores) than controls. The PAE− group had lower fractional anisotropy (FA) in the bilateral cingulum and left uncinate fasciculus, and smaller volumes in the left anterior cingulate cortex than controls and the PAE+ group. The PAE− group also had higher mean diffusivity (MD) in the left uncinate than the PAE+ group, and smaller right anterior cingulate and superior frontal gyrus volumes than controls. These findings show different brain structure and mental health symptom profiles in children with PAE with and without postnatal adversity, highlighting the need to consider adverse postnatal exposures in individuals with PAE.

Child maltreatment and depression: A meta-analysis of studies using the Childhood Trauma Questionnaire

BACKGROUND

Researchers have documented that child maltreatment is associated with adverse long-term consequences for mental health, including increased risk for depression. Attempts to conduct meta-analyses of the association between different forms of child maltreatment and depressive symptomatology in adulthood, however, have been limited by the wide range of definitions of child maltreatment in the literature.

OBJECTIVE

We sought to meta-analyze a single, widely-used dimensional measure of child maltreatment, the Childhood Trauma Questionnaire, with respect to depression diagnosis and symptom scores.

PARTICIPANTS AND SETTING

192 unique samples consisting of 68,830 individuals.

METHODS

We explored the association between total scores and scores from specific forms of child maltreatment (i.e., emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect) and depression using a random-effects meta-analysis.

RESULTS

We found that higher child maltreatment scores were associated with a diagnosis of depression (g = 1.07; 95 % CI, 0.95-1.19) and with higher depression symptom scores (Z = .35; 95 % CI, .32-.38). Moreover, although each type of child maltreatment was positively associated with depression diagnosis and scores, there was variability in the size of the effects, with emotional abuse and emotional neglect demonstrating the strongest associations.

CONCLUSIONS

These analyses provide important evidence of the link between child maltreatment and depression, and highlight the particularly larger association with emotional maltreatment in childhood.

Additional Insights into the Relationship Between Brain Network Architecture and Susceptibility and Resilience to the Psychiatric Sequelae of Childhood Maltreatment

Childhood maltreatment is associated with increased risk for psychiatric and substance use disorders. However, some maltreated individuals appear resilient to these consequences while manifesting the same array of brain changes as maltreated individuals with psychopathology. Hence, a critical issue has been to identify compensatory brain alterations in these resilient individuals. We recently reported that maltreatment is associated with a more vulnerable structural brain network architecture. Resilient individuals have this same vulnerability but appeared to be able to effectively compensate due to reduced nodal efficiency (ability of a node to influence the global network) in 9 specific brain regions that moderate the relationship between maltreatment and psychopathology. Following up we now report that network vulnerability increases progressively during late adolescence to plateau at about 21 years of age, which may help to explain age of onset of psychopathology. Further, we found that network vulnerability was most significantly affected by parental verbal abuse between 16-18 years of age and number of types of maltreatment during childhood. Asymptomatic individuals with no history of psychopathology had more prominent alterations in nodal efficiency than asymptomatic individuals with prior history, who specifically showed reduced nodal efficiency in right amygdala and right subcallosal gyrus. Experiencing inadequate financial sufficiency during childhood increased risk of susceptibility versus resilience by 2.98-fold (95% CI 1.49-5.97, p = 0.002) after adjusting for differences in exposure to maltreatment. Interestingly, adequate-to-higher financial sufficiency appeared to be protective and was associated with reduced nodal efficiency in the right postcentral gyrus and subcallosal gyrus 'resilience' nodes.

Alterations in the fronto-limbic network and corpus callosum in borderline-personality disorder

Neuroimaging research provides evidence of grey matter changes in the prefrontal-limbic network in borderline personality disorder (BPD), yet research scarcely examines the white matter (WM) within this circuitry. The present study aimed to explore WM in prefrontal-limbic brain networks within BPD. Quantitative diffusion tensor imaging (DTI-MRI) measures of fractional anisotropy (FA) and mean diffusion (MD) were used to analyze the neural pathways in fifteen individuals with BPD (M = 25, SD = 6.76), in comparison to thirteen healthy individuals (M = 27.92, SD = 8.41). Quantitative DTI-MRI measures of FA and MD were evaluated for the cingulum, the fornix, the corpus callosum (CC), the inferior longitudinal fasciculus (ILF), the superior longitudinal fasciculus (SLF) and the uncinate fasciculus (UF). Lower FA values for both the left and the right cingulum, the genu, body, and splenium of the CC, left ILF and right SLF were found in BPD, compared to healthy individuals. MD values were higher for the genu and splenium of the CC in BPD. The findings indicate that a large-scale emotional brain network is affected in BPD with alterations in MD and FA of WM prefrontal-limbic pathways of the heteromodal association cortex involved in emotion processing and emotion regulation.

Reduced fractional anisotropy in depressed patients due to childhood maltreatment rather than diagnosis

Reduced fractional anisotropy (FA) associated with Major Depressive Disorder (MDD) overlaps anatomically with effects of childhood maltreatment experiences. The aim of this study was, therefore, to replicate the negative effect of childhood maltreatment on white matter fiber structure and to demonstrate, that alterations in MDD might be partially attributed to the higher occurrence of childhood maltreatment in MDD. Two independent cohorts (total N = 1 256) were investigated in a diffusion tensor imaging study: The Münster Neuroimaging Cohort (MNC, N = 186 MDD, N = 210 healthy controls, HC) as discovery sample and the Marburg-Münster Affective Disorders Cohort Study (MACS, N = 397 MDD, N = 462 HC) as replication sample. The effects of diagnosis (HC vs. MDD) and Childhood Trauma Questionnaire (CTQ) scores on FA were analyzed. A main effect of diagnosis with higher FA in MDD patients compared with HC was found in the MNC (p_FWE = 0.021), but not in the MACS (p_FWE = 0.52) before correcting for CTQ. A significant negative correlation of FA with CTQ emerged in both cohorts (MNC: p_FWE = 0.006, MACS: p_FWE = 0.012) in several tracts previously described in the literature. No CTQ × diagnosis interaction could be detected. Any main effect of diagnosis was abolished after correcting for CTQ (MNC: p_FWE = 0.562, MACS: p_FWE = 0.115). No differences in FA between MDD and HC could be found after correcting for childhood maltreatment, suggesting that previously reported group differences might be attributed partially to higher levels of maltreatment experiences in MDD rather than diagnosis itself. Furthermore, a well-established finding of reduced FA following childhood maltreatment experiences was replicated.

The superior longitudinal fasciculus and its functional triple-network mechanisms in brooding

Brooding, which refers to a repetitive focus on one's distress, is associated with functional connectivity within Default-Mode, Salience, and Executive-Control networks (DMN; SN; ECN), comprising the so-called "triple-network" of attention. Individual differences in brain structure that might perseverate dysfunctional connectivity of brain networks associated with brooding are less clear, however. Using diffusion and functional Magnetic Resonance Imaging, we explored multimodal relationships between brooding severity, white-matter microstructure, and resting-state functional connectivity in depressed adults (N = 32-44), and then examined whether findings directly replicated in a demographically-similar, independent sample (N = 36-45). Among the fully-replicated results, three core findings emerged. First, brooding severity is associated with functional integration and segregation of the triple-network, particularly with a Precuneal subnetwork of the DMN. Second, microstructural asymmetry of the Superior Longitudinal Fasciculus (SLF) provides a robust structural connectivity basis for brooding and may account for over 20% of its severity (Discovery: adj. R² = 0.18; Replication: adj. R² = 0.22; MSE = 0.06, Predictive R² = 0.22). Finally, microstructure of the right SLF and auxiliary white-matter is associated with the functional connectivity correlates of brooding, both within and between components of the triple-network (Discovery: adj. R² = 0.21; Replication: adj. R² = 0.18; MSE = 0.03, Predictive R² = 0.21-0.22). By cross-validating multimodal discovery with replication, the present findings help to reproducibly unify disparate perspectives of brooding etiology. Based on that synthesis, our study reformulates brooding as a microstructural-functional connectivity neurophenotype.

Altered white matter connectivity in young people exposed to childhood abuse: a tract-based spatial statistics (TBSS) and tractography study

BACKGROUND

Childhood abuse is associated with structural brain abnormalities. Few studies have investigated white matter tract abnormalities in medication-naive, drug-free individuals who experienced childhood abuse. We examined the association between childhood abuse and abnormalities in white matter tracts in that population, controlling for psychiatric comorbidities.

METHODS

We collected diffusion tensor imaging data for age- and sex-matched youth with childhood abuse, psychiatric controls (matched for psychiatric diagnoses) and healthy controls. Tract-specific analysis was conducted using tractography. Tract-based spatial statistics (TBSS) was used to assess group differences in fractional anisotropy (FA) at the whole-brain level.

RESULTS

We included 20 youth who experienced childhood abuse, 18 psychiatric controls and 25 healthy controls in our analysis. Tractography analysis showed abuse-specific reduced tract volume in the inferior longitudinal fasciculus (ILF) and inferior frontal-occipital fasciculus (IFoF) in the abuse group relative to both healthy and psychiatric controls. Furthermore, abnormalities in the left IFoF were associated with greater abuse severity. The TBSS analysis showed significantly reduced FA in a left-hemispheric cluster comprising the ILF, IFoF and corpus callosum splenium in the abuse group relative to healthy and psychiatric controls.

LIMITATIONS

It is unclear to what extent pubertal development, malnutrition and prenatal drug exposure may have influenced the findings.

CONCLUSION

Childhood abuse is associated with altered structure of neural pathways connecting the frontal, temporal and occipital cortices that are known to mediate affect and cognitive control. The abuse-specific deficits in the ILF and IFoF suggest that fibre tracts presumably involved in conveying and processing the adverse abusive experience are specifically compromised in this population.

Longitudinal diffusion weighted imaging of limbic regions in patients with major depressive disorder after 6 years and partial to full remission

The objective of this study was to determine the effect of major depressive disorder (MDD) on white matter microstructures after a 6-year period compared to healthy controls (HC). This study included a small sample size of 26 participants, including 14 patients with MDD clinically diagnosed at baseline, and 12 HCs. MRI brain scans were conducted at baseline and follow-up, 75.32 (±2.25) months after the initial scan. Tractography of 7 regions including the fornix, cingulum, superior longitudinal fasciculus, inferior fronto-occipital fasciculus and uncinate fasciculus were conducted using ExploreDTI software. Both groups showed significant reduction in tract integrity between time points. MDD diagnosis was shown to have an effect on longitudinal FA of the left dorsal cingulum and the left parahippocampal cingulum. A significant inverse relationship was found between ΔFA [baseline FA - follow-up FA] of the right uncinate fasciculus and the left rostral cingulum with ΔHAM-D [baseline HAM-D - follow-up HAM-D] within the MDD group. These preliminary findings support the hypothesis that limbic structures including the cingulum are involved in MDD pathophysiology and may be affected even after remission. Moreover, they indicate that recovery from depression symptoms may slow the rate of WM degradation associated with aging in these regions of interest.

Intrinsic gray-matter connectivity of the brain in major depressive disorder

BACKGROUND

Major depressive disorder (MDD) has been assumed to be associated with aberrant brain connectivity. However, research suggests that brain connectivity abnormalities should not be restricted to extrinsic white matter connectivity, but may also impact on intrinsic gray matter connectivity. Therefore, our study aimed to investigate the intrinsic gray-matter connectivity in MDD.

METHODS

The participants were 16 first-episode, drug-naïve patients with MDD and 16 healthy controls matched on age and gender. All participants were scanned by 3.0T structural magnetic resonance imaging. Global and local intrinsic gray-matter connectivity were measured based on surface-based geodesic distances, including mean coritical separation distances (MSDs), perimeter function, and radius function.

RESULTS

MDD patients had significantly lower MSDs in the left postcentral gyrus and higher MSDs in the left superior parietal cortex. Marginally significant correlation was observed between MSDs in the left postcentral gyrus and symptoms of depression. Compared with healthy controls, depressed subjects had abnormal local intrinsic gray-matter connectivity in the left postcentral gyrus, the left transverse temporal gyrus, the right lingual gyrus, the right lateral occipital cortex, and the right superior frontal gyrus. Furthermore, local intrinsic gray matter connections of these brain areas were associated with some symptoms of depression.

LIMITATIONS

The small sample size limited the interpretability of our potential conclusions.

CONCLUSION

Aberrant intrinsic gray-matter connectivity was observed in depressed subjects, indicating abnormal intrinsic wiring cost of brain architecture. This might help explain the aberrant topological properties of brain functional connectivity and provide insights into the vulnerability of MDD.

Tryptophan hydroxylase-2 polymorphism is associated with white matter integrity in first-episode, medication-naïve major depressive disorder patients

Considerable evidence suggests that the tryptophan hydroxylase-2 (TPH2) gene is associated with the pathophysiology of major depressive disorder (MDD). In the present study, we investigated alterations of white matter (WM) integrity and the impact of TPH2 polymorphism on WM in a sample of 118 first-episode, medication-naïve, MDD patients and 118 well-matched healthy controls. Whole brain analyses of fractional anisotropy (FA) were performed using tract-based spatial statistics (TBSS). The results showed that the MDD group had significantly reduced FA values for the genu and body of the corpus callosum (CC) and the bilateral anterior corona radiate (ACR). In the MDD patient group, the GG homozygote subgroup exhibited a widespread reduction of FA (uncorrected) and significantly reduced FA in the left retrolenticular portion of the internal capsule and left superior longitudinal fasciculus (SLF) compared with those of the T carriers (GT/TT) (FWE corrected). No significant correlation was found between the FA values in any brain region and the patients' clinical variables. Our findings demonstrate the presence of abnormal white matter integrity in untreated patients with first-episode depression. TPH2-rs4570625 polymorphisms may be involved in the pathological mechanism of WM microarchitecture in patients.

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.

The effects of bullying in depression on white matter integrity

Individuals with elevated symptoms of depression exhibit alterations in white matter integrity, including lower fractional anisotropy (FA) evident on diffusion tensor imaging (DTI). Similarly, individuals with a history of early life stress (ELS) exhibit lower FA in the white matter independent of concurrent depression. Prior studies have not determined whether the neuroimaging signature of comorbid ELS and adult depression differs from the pattern of brain white matter changes associated with depression in the absence of self-reported ELS. The current study examined FA in multiple white matter tracts in 186 adults (93 males; 93 females) with a current diagnosis of major depressive disorder, including 88 who reported a history of bullying before the age of 18 (43 males; 45 females). All patients were antidepressant medication free at the time of testing. After adjusting for demographics and other ELS subtypes, participants with a history of bullying exhibited increased FA in the right medial lemniscus (p =.039) and left posterior corona radiata (p =.008) compared to participants with depression but no self-reported history of bullying. Both groups endorsed similar levels of depression. Group differences were most pronounced among individuals who endorsed bullying in late adolescence (14-17 years of age). Results suggest bullying in late adolescence is uniquely related to abnormal brain microstructure among individuals with current diagnoses of depression, possibly due to an overactive fear response. Further work is needed to differentiate why ELS within bullying is associated with higher FA.

Anatomical and Neurochemical Correlates of Parental Verbal Abuse: A Combined MRS-Diffusion MRI Study

Despite the critical impact of parental dialog on children who remain physically and psychologically dependent, most studies have focused on brain alterations in people exposed to moderate-to-high levels of emotional maltreatment with/without psychopathology. We measured metabolites in the pregenual anterior cingulate cortex (pgACC) acquired with single-voxel proton magnetic resonance spectroscopy and anatomical connectivity assessed with probabilistic tractography in 46 healthy young adults who experienced no-to-low level parental verbal abuse (paVA) during their childhood and adolescence. The partial least square regression (PLSR) model showed that individual variance of perceived paVA was associated with chemical properties and structural connectivity of pregenual anterior cingulate cortex (pgACC; prediction R 2 = 0.23). The jackknife test was used to identify features that significantly contributed to the partial least square regression (PLSR) model; a negative association of paVA was found with myo-inositol concentration, anatomical connectivities with the right caudate and with the right transverse temporal gyrus. Of note, positive associations were also found with the left pars triangularis, left cuneus, right inferior temporal cortex, right entorhinal cortex and right amygdala. Our results showing both a negative association of frontal glial function and positive associations of anatomical connectivities in several networks associated with threat detection or visual information processing suggest both anatomical and neurochemical adaptive changes in medial frontolimbic networks to low-level paVA experiences.

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.

Child abuse associates with an imbalance of oligodendrocyte-lineage cells in ventromedial prefrontal white matter

Child abuse (CA) is a major risk factor for depression, and strongly associates with suicidal behavior during adulthood. Neuroimaging studies have reported widespread changes in white matter integrity and brain connectivity in subjects with a history of CA. Although such observations could reflect changes in myelin and oligodendrocyte function, their cellular underpinnings have never been addressed. Using postmortem brain samples from depressed suicides with or without history of CA and matched controls (18 per group), we aimed to characterize the effects of CA on oligodendrocyte-lineage (OL) cells in the ventromedial prefrontal white matter. Using immunoblotting, double-labeling immunofluorescence and stereological estimates of stage-specific markers, we found that CA is associated with increased numbers of mature myelinating oligodendrocytes, accompanied by decreased numbers of more immature OL cells. This was paralleled by an increased expression of transcription factor MASH1, which is involved in the terminal differentiation of the OL, suggesting that CA may trigger an increased maturation, or bias the populations of OL cells toward a more mature phenotype. Some of these effects, which were absent in the brain of depressed suicides with no history of CA, were also found to recover with age, suggesting that changes in the balance of the OL may reflect a transient adaptive mechanism triggered by early-life adversity. In conclusion, our results indicate that CA in depressed suicides is associated with an imbalance of the OL in the ventromedial prefrontal white matter, an effect that could lead to myelin remodeling and long-term connectivity changes within the limbic network.

Whole mouse brain structural connectomics using magnetic resonance histology

Diffusion tensor histology holds great promise for quantitative characterization of structural connectivity in mouse models of neurological and psychiatric conditions. There has been extensive study in both the clinical and preclinical domains on the complex tradeoffs between the spatial resolution, the number of samples in diffusion q-space, scan time, and the reliability of the resultant data. We describe here a method for accelerating the acquisition of diffusion MRI data to support quantitative connectivity measurements in the whole mouse brain using compressed sensing (CS). The use of CS allows substantial increase in spatial resolution and/or reduction in scan time. Compared to the fully sampled results at the same scan time, the subtle anatomical details of the brain, such as cortical layers, dentate gyrus, and cerebellum, were better visualized using CS due to the higher spatial resolution. Compared to the fully sampled results at the same spatial resolution, the scalar diffusion metrics, including fractional anisotropy (FA) and mean diffusivity (MD), showed consistently low error across the whole brain (< 6.0%) even with 8.0 times acceleration. The node properties of connectivity (strength, cluster coefficient, eigenvector centrality, and local efficiency) demonstrated correlation of better than 95.0% between accelerated and fully sampled connectomes. The acceleration will enable routine application of this technology to a wide range of mouse models of neurologic diseases.

Development and evaluation of a multimodal marker of major depressive disorder

This study aimed to identify biomarkers of major depressive disorder (MDD), by relating neuroimage-derived measures to binary (MDD/control), ordinal (severe MDD/mild MDD/control), or continuous (depression severity) outcomes. To address MDD heterogeneity, factors (severity of psychic depression, motivation, anxiety, psychosis, and sleep disturbance) were also used as outcomes. A multisite, multimodal imaging (diffusion MRI [dMRI] and structural MRI [sMRI]) cohort (52 controls and 147 MDD patients) and several modeling techniques-penalized logistic regression, random forest, and support vector machine (SVM)-were used. An additional cohort (25 controls and 83 MDD patients) was used for validation. The optimally performing classifier (SVM) had a 26.0% misclassification rate (binary), 52.2 ± 1.69% accuracy (ordinal) and r = .36 correlation coefficient (p < .001, continuous). Using SVM, R² values for prediction of any MDD factors were <10%. Binary classification in the external data set resulted in 87.95% sensitivity and 32.00% specificity. Though observed classification rates are too low for clinical utility, four image-based features contributed to accuracy across all models and analyses-two dMRI-based measures (average fractional anisotropy in the right cuneus and left insula) and two sMRI-based measures (asymmetry in the volume of the pars triangularis and the cerebellum) and may serve as a priori regions for future analyses. The poor accuracy of classification and predictive results found here reflects current equivocal findings and sheds light on challenges of using these modalities for MDD biomarker identification. Further, this study suggests a paradigm (e.g., multiple classifier evaluation with external validation) for future studies to avoid nongeneralizable results.

Neural networks in bottom up 'experiential emotion regulation'

Emotion regulation influences how and when we experience emotion, impacting our sense of self and well being. While previous brain research on emotion regulation has focused on gray matter correlates of emotion regulation, this study represents a first exploratory study on white matter integrity of brain networks of 'emotional approach' as a bottom up experiential emotion regulation-strategy. Responding to the gap between cognitive and affective approaches of emotion regulation, pertaining to some of the daily emotional stressors, the present study investigates brain pathways of individual differences in 'emotional approach', or the tendency to affectively acknowledge, understand and express emotional experience (cf. [1]). Diffusion tensor magnetic resonance imaging (DTI-MRI) measures of fractional anisotropy (FA) and mean diffusion (MD) evaluated dispositional emotion regulation in a group of 21 women with a 'high emotional approach' (HEA) (N = 11) and a 'low emotional approach' (LEA) (N = 10). HEA exhibited more FA of the cingulum, supporting emotion processing and emotion regulation, whereas LEA correlated to a higher FA in the right corticospinal tracts, supporting automatic action tendencies and a higher FA in the superior longitudinal fasciculus (SLF), supporting cognitive control and monitoring of emotion. LEA also correlated with an increase in MD in the body (p. = 0.05) and in the splenium of the corpus callosum (CC). A higher FA in the inferior longitudinal fasciculus (IFL) may indicate higher visual- affective integration within emotion processing, whereas more MD in the body and splenium of the CC decreases interhemispheric integration of emotional information within emotion processing and emotion regulation.

Differential Associations of Distinct Forms of Childhood Adversity With Neurobehavioral Measures of Reward Processing: A Developmental Pathway to Depression

Childhood adversity is associated with altered reward processing, but little is known about whether this varies across distinct types of adversity. In a sample of 94 children (6-19 years), we investigated whether experiences of material deprivation, emotional deprivation, and trauma have differential associations with reward-related behavior and white matter microstructure in tracts involved in reward processing. Material deprivation (food insecurity), but not emotional deprivation or trauma, was associated with poor reward performance. Adversity-related influences on the integrity of white matter microstructure in frontostriatal tracts varied across childhood adversity types, and reductions in frontostriatal white matter integrity mediated the association of food insecurity with depressive symptoms. These findings document distinct behavioral and neurodevelopmental consequences of specific forms of adversity that have implications for psychopathology risk.

Fibre tract analysis using diffusion tensor imaging reveals aberrant connectivity in a rat model of depression

OBJECTIVES

Abnormal brain connectivity has been described in depressive disorder. However, these studies are correlational or cross-sectional and their design does not examine causal relationships. We aimed to investigate structural connectivity in a genetic rat model of depression.

METHODS

Using diffusion tensor imaging (DTI), we reconstructed white matter tracts and analysed fractional anisotropy (FA) and diffusivity indices (mean, axial and radial) to investigate structural connectivity in fibre tracts implicated in major depression: the corpus callosum, fornix, cingulum and anterior commissures.

RESULTS

Tractography-based analysis revealed that, compared to Wistar control rats, the Wistar-Kyoto strain (WKY) rat model of depression exhibited decreased connectivity, manifested by decreased FA in the corpus callosum, right and left anterior commissures. A statistical trend of decreased FA was observed in both the right and left cingulum. Increased diffusivity (mean diffusion) was detected in both the corpus callosum and the fornix of WKY rats compared to controls. Voxel-based analysis confirmed differences between WKY and controls in the regions investigated.

CONCLUSIONS

Decreased connectivity in a genetic rat model of depression corroborates the findings in patients suffering from major depression suggesting that the vulnerability for developing depression is mainly polygenic and less likely to be due to childhood adversity per se.

Childhood maltreatment moderates the effect of combat exposure on cingulum structural integrity

Limbic white matter pathways link emotion, cognition, and behavior and are potentially malleable to the influences of traumatic events throughout development. However, the impact of interactions between childhood and later life trauma on limbic white matter pathways has yet to be examined. Here, we examined whether childhood maltreatment moderated the effect of combat exposure on diffusion tensor imaging measures within a sample of military veterans (N = 28). We examined five limbic tracts of interest: two components of the cingulum (cingulum, cingulate gyrus, and cingulum hippocampus [CGH]), the uncinate fasciculus, the fornix/stria terminalis, and the anterior limb of the internal capsule. Using effect sizes, clinically meaningful moderator effects were found only within the CGH. Greater combat exposure was associated with decreased CGH fractional anisotropy (overall structural integrity) and increased CGH radial diffusivity (perpendicular water diffusivity) among individuals with more severe childhood maltreatment. Our findings provide preliminary evidence of the moderating effect of childhood maltreatment on the relationship between combat exposure and CGH structural integrity. These differences in CGH structural integrity could have maladaptive implications for emotion and memory, as well as provide a potential mechanism by which childhood maltreatment induces vulnerability to later life trauma exposure.

Prepartum and Postpartum Maternal Depressive Symptoms Are Related to Children's Brain Structure in Preschool

BACKGROUND

Perinatal maternal depression is a serious health concern with potential lasting negative consequences for children. Prenatal depression is associated with altered brain gray matter in children, though relations between postpartum depression and children's brains and the role of white matter are unclear.

METHODS

We studied 52 women who provided Edinburgh Postnatal Depression Scale (EPDS) scores during each trimester of pregnancy and at 3 months postpartum and their children who underwent magnetic resonance imaging at age 2.6 to 5.1 years. Associations between maternal depressive symptoms and magnetic resonance imaging measures of cortical thickness and white matter structure in the children were investigated.

RESULTS

Women's second trimester EPDS scores negatively correlated with children's cortical thickness in right inferior frontal and middle temporal regions and with radial and mean diffusivity in white matter emanating from the inferior frontal area. Cortical thickness, but not diffusivity, correlations survived correction for postpartum EPDS. Postpartum EPDS scores negatively correlated with children's right superior frontal cortical thickness and with diffusivity in white matter originating from that region, even after correcting for prenatal EPDS.

CONCLUSIONS

Higher maternal depressive symptoms prenatally and postpartum are associated with altered gray matter structure in children; the observed white matter correlations appear to be uniquely related to the postpartum period. The reduced thickness and diffusivity suggest premature brain development in children exposed to higher maternal perinatal depressive symptoms. These results highlight the importance of ensuring optimal women's mental health throughout the perinatal period, because maternal depressive symptoms appear to increase children's vulnerability to nonoptimal brain development.

Effects of a Polymorphism of the Neuronal Amino Acid Transporter SLC6A15 Gene on Structural Integrity of White Matter Tracts in Major Depressive Disorder

Background

The SLC6A15 gene has been identified as a novel candidate gene for major depressive disorder (MDD). It is presumed to be involved in the pathophysiology of MDD through regulation of glutamate transmission in the brain. However, the involvement of this gene in microstructural changes in white matter (WM) tracts remains unclear. We aimed to investigate the influence of a polymorphism of this gene (rs1545853) on the structural integrity of WM tracts in the cortico-limbic network.

Methods

Eighty-six patients with MDD and 64 healthy controls underwent T1-weighted structural magnetic resonance imaging, including diffusion tensor imaging (DTI), and genotype analysis. We selected the genu of the corpus callosum, the uncinate fasciculus, cingulum, and fornix as regions of interest, and extracted fractional anisotropy (FA) values using the FMRIB Diffusion Toolbox software.

Results

FA values for the left parahippocampal cingulum (PHC) was significantly reduced in the patients with MDD compared to healthy control participants (p = 0.004). We also found that MDD patients with the A allele showed reduced FA values for the left PHC than did healthy controls with the A allele (p = 0.012). There was no significant difference in the FA value of left PHC for the comparison between the G homozygotes of MDD and healthy control group.

Conclusions

We observed an association between the risk allele of the SLC6A15 gene rs1545843 and the WM integrity of the PHC in MDD patients, which is known to play an important role in the neural circuit involved in emotion processing.

Annual Research Review: Enduring neurobiological effects of childhood abuse and neglect

BACKGROUND

Childhood maltreatment is the most important preventable cause of psychopathology accounting for about 45% of the population attributable risk for childhood onset psychiatric disorders. A key breakthrough has been the discovery that maltreatment alters trajectories of brain development.

METHODS

This review aims to synthesize neuroimaging findings in children who experienced caregiver neglect as well as from studies in children, adolescents and adults who experienced physical, sexual and emotional abuse. In doing so, we provide preliminary answers to questions regarding the importance of type and timing of exposure, gender differences, reversibility and the relationship between brain changes and psychopathology. We also discuss whether these changes represent adaptive modifications or stress-induced damage.

RESULTS

Parental verbal abuse, witnessing domestic violence and sexual abuse appear to specifically target brain regions (auditory, visual and somatosensory cortex) and pathways that process and convey the aversive experience. Maltreatment is associated with reliable morphological alterations in anterior cingulate, dorsal lateral prefrontal and orbitofrontal cortex, corpus callosum and adult hippocampus, and with enhanced amygdala response to emotional faces and diminished striatal response to anticipated rewards. Evidence is emerging that these regions and interconnecting pathways have sensitive exposure periods when they are most vulnerable.

CONCLUSIONS

Early deprivation and later abuse may have opposite effects on amygdala volume. Structural and functional abnormalities initially attributed to psychiatric illness may be a more direct consequence of abuse. Childhood maltreatment exerts a prepotent influence on brain development and has been an unrecognized confound in almost all psychiatric neuroimaging studies. These brain changes may be best understood as adaptive responses to facilitate survival and reproduction in the face of adversity. Their relationship to psychopathology is complex as they are discernible in both susceptible and resilient individuals with maltreatment histories. Mechanisms fostering resilience will need to be a primary focus of future studies.

A COMPREHENSIVE EXAMINATION OF WHITE MATTER TRACTS AND CONNECTOMETRY IN MAJOR DEPRESSIVE DISORDER

BACKGROUND

Major depressive disorder (MDD) is a debilitating disorder characterized by widespread brain abnormalities. The literature is mixed as to whether or not white matter abnormalities are associated with MDD. This study sought to examine fractional anisotropy (FA) in white matter tracts in individuals with MDD using diffusion tensor imaging (DTI).

METHODS

139 participants with MDD and 39 healthy controls (HC) in a multisite study were included. DTI scans were acquired in 64 directions and FA was determined in the brain using four methods: region of interest (ROI), tract-based spatial statistics (TBSS), and diffusion tractography. Diffusion connectometry was used to identify white matter pathways associated with MDD.

RESULTS

There were no significant differences when comparing FA in MDD and HC groups using any method. In the MDD group, there was a significant relationship between depression severity and FA in the right medial orbitofrontal cortex, and between age of onset of MDD and FA in the right caudal anterior cingulate cortex using the ROI method. There was a significant relationship between age of onset and connectivity in the thalamocortical radiation, inferior longitudinal fasciculus, and cerebellar tracts using diffusion connectometry.

CONCLUSIONS

The lack of group differences in FA and connectometry analysis may result from the clinically heterogenous nature of MDD. However, the relationship between FA and depression severity may suggest a state biomarker of depression that should be investigated as a potential indicator of response. Age of onset may also be a significant clinical feature to pursue when studying white matter tracts.

Single-Nucleotide Polymorphism of the FKBP5 Gene and Childhood Maltreatment as Predictors of Structural Changes in Brain Areas Involved in Emotional Processing in Depression

The gene expressing the FK506 binding protein 51 (FKBP5) is involved in the regulation of glucocorticoid receptor sensitivity. The rs1360780 SNP in this gene (T allele vs C homozygous) has been found to be associated with major depressive disorder (MDD). The aim of our study was to investigate whether this polymorphism might be associated with altered brain structure and function in a cohort of 40 patients with MDD and 43 healthy controls. A functional magnetic resonance imaging (fMRI) emotional attention task was employed. Diffusion tensor imaging (DTI) was also conducted, extracting mean diffusivity (MD) and fractional anisotropy (FA) from brain areas that showed functional differences between patients expressing the two alleles of the rs1360780 SNP. Finally, the effect of the interaction of childhood adversity as measured by the Childhood trauma Questionnaire (CTQ) and rs1360780 allele status was analyzed in relation to DTI measures using a general linear model. All results presented are family-wise error (FWE) corrected. Functional interactions were found between genotype and diagnosis (p<0.01). Patients carrying the high-risk allele, compared with patients not carrying it, showed reduced activity in the rolandic operculum, Heschl gyrus, insula, parahippocampal gyrus, posterior cingulate cortex, inferior frontal gyrus (p<0.05 for all measures); and increased MD and reduced FA measures in many of these regions (p<0.05). An interaction between CTQ scores and allele status was associated with DTI changes in the insula, rolandic operculum, and inferior frontal gyrus. Here, the presence of both the high-risk allele and higher CTQ scores was associated with higher MD and lower FA values (p<0.05). In conclusion, MDD patients expressing the T allele of rs1360780, compared with C homozygous patients, exhibit functional and structural differences in areas involved in emotional perception and inhibition. The interaction between the T allele and childhood maltreatment explained our structural findings in these regions, suggesting that their altered maturation and function might be influenced by early chronic stress in the presence of this genetic trait.