A Comparison of Quantitative R1 and Cortical Thickness in Identifying Age, Lifespan Dynamics, and Disease States of the Human Cortex.

Brain development and aging are complex processes that unfold in multiple brain regions simultaneously. Recently, models of brain age prediction have aroused great interest, as these models can potentially help to understand neurological diseases and elucidate basic neurobiological mechanisms. We test whether quantitative magnetic resonance imaging can contribute to such age prediction models. Using R1, the longitudinal rate of relaxation, we explore lifespan dynamics in cortical gray matter. We compare R1 with cortical thickness, a well-established biomarker of brain development and aging. Using 160 healthy individuals (6-81 years old), we found that R1 and cortical thickness predicted age similarly, but the regions contributing to the prediction differed. Next, we characterized R1 development and aging dynamics. Compared with anterior regions, in posterior regions we found an earlier R1 peak but a steeper postpeak decline. We replicate these findings: firstly, we tested a subset (N = 10) of the original dataset for whom we had additional scans at a lower resolution; and second, we verified the results on an independent dataset (N = 34). Finally, we compared the age prediction models on a subset of 10 patients with multiple sclerosis. The patients are predicted older than their chronological age using R1 but not with cortical thickness.

Common and distinct patterns of grey-matter volume alteration in major depression and bipolar disorder: evidence from voxel-based meta-analysis.

Finding robust brain substrates of mood disorders is an important target for research. The degree to which major depression (MDD) and bipolar disorder (BD) are associated with common and/or distinct patterns of volumetric changes is nevertheless unclear. Furthermore, the extant literature is heterogeneous with respect to the nature of these changes. We report a meta-analysis of voxel-based morphometry (VBM) studies in MDD and BD. We identified studies published up to January 2015 that compared grey matter in MDD (50 data sets including 4101 individuals) and BD (36 data sets including 2407 individuals) using whole-brain VBM. We used statistical maps from the studies included where available and reported peak coordinates otherwise. Group comparisons and conjunction analyses identified regions in which the disorders showed common and distinct patterns of volumetric alteration. Both disorders were associated with lower grey-matter volume relative to healthy individuals in a number of areas. Conjunction analysis showed smaller volumes in both disorders in clusters in the dorsomedial and ventromedial prefrontal cortex, including the anterior cingulate cortex and bilateral insula. Group comparisons indicated that findings of smaller grey-matter volumes relative to controls in the right dorsolateral prefrontal cortex and left hippocampus, along with cerebellar, temporal and parietal regions were more substantial in major depression. These results suggest that MDD and BD are characterised by both common and distinct patterns of grey-matter volume changes. This combination of differences and similarities has the potential to inform the development of diagnostic biomarkers for these conditions.

Telomere length and cortisol reactivity in children of depressed mothers.

A growing body of research demonstrates that individuals diagnosed with major depressive disorder (MDD) are characterized by shortened telomere length, which has been posited to underlie the association between depression and increased instances of medical illness. The temporal nature of the relation between MDD and shortened telomere length, however, is not clear. Importantly, both MDD and telomere length have been associated independently with high levels of stress, implicating dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and anomalous levels of cortisol secretion in this relation. Despite these associations, no study has assessed telomere length or its relation with HPA-axis activity in individuals at risk for depression, before the onset of disorder. In the present study, we assessed cortisol levels in response to a laboratory stressor and telomere length in 97 healthy young daughters of mothers either with recurrent episodes of depression (i.e., daughters at familial risk for depression) or with no history of psychopathology. We found that daughters of depressed mothers had shorter telomeres than did daughters of never-depressed mothers and, further, that shorter telomeres were associated with greater cortisol reactivity to stress. This study is the first to demonstrate that children at familial risk of developing MDD are characterized by accelerated biological aging, operationalized as shortened telomere length, before they had experienced an onset of depression; this may predispose them to develop not only MDD but also other age-related medical illnesses. It is critical, therefore, that we attempt to identify and distinguish genetic and environmental mechanisms that contribute to telomere shortening.

A profile approach to impulsivity in bipolar disorder: the key role of strong emotions.

OBJECTIVE: Bipolar disorder has been associated with elevated impulsivity - a complex construct subsuming multiple facets. We aimed to compare specific facets of impulsivity in bipolar disorder, including those related to key psychological correlates of the illness: reward sensitivity and strong emotion. METHOD: Ninety-one individuals diagnosed with bipolar I disorder (inter-episode period) and 80 controls completed several well-validated impulsivity measures, including those relevant to reward (Fun-seeking subscale of the Behavioral Activation System scale) and emotion (Positive Urgency and Negative Urgency scales). RESULTS: Bipolar participants reported higher impulsivity scores than did controls on all of the impulsivity measures, except the Fun-seeking subscale of the Behavioral Activation System scale. Positive Urgency - a measure assessing the tendency to act impulsively when experiencing strong positive emotion - yielded the largest group differences: F(1,170) = 78.69, P < 0.001, partial η(2)  = 0.316. Positive Urgency was also associated with poorer psychosocial functioning in the bipolar group: ΔR(2)  = 0.24, b = -0.45, P < 0.001. CONCLUSION: Individuals with bipolar I disorder appear to be at particular risk of behaving impulsively when experiencing strong positive emotions. Findings provide an important first step toward developing a more refined understanding of impulsivity in bipolar disorder with the potential to inform targeted interventions.

Neighborhood disadvantage and parenting predict longitudinal clustering of uncinate fasciculus microstructural integrity and clinical symptomatology in adolescents.

Parenting behaviors and neighborhood environment influence the development of adolescents' brains and behaviors. Simultaneous trajectories of brain and behavior, however, are understudied, especially in these environmental contexts. In this four-wave study spanning 9-18 years of age (N=224 at baseline, N=138 at final assessment) we used longitudinal k-means clustering to identify clusters of participants with distinct trajectories of uncinate fasciculus (UF) fractional anisotropy (FA) and anxiety symptoms; we examined behavioral outcomes and identified environmental factors that predicted cluster membership. We identified three clusters of participants: 1) high UF FA and low symptoms ("low-risk"); 2) low UF FA and high symptoms ("high-risk"); and 3) low UF FA and low symptoms ("resilient"). Adolescents in disadvantaged neighborhoods were more likely to be in the resilient than high-risk cluster if they also experienced maternal warmth. Thus, neighborhood disadvantage may confer neural risk for psychopathology that can be buffered by maternal warmth, highlighting the importance of considering multiple environmental influences in understanding emotional and neural development in youth.

A Data-Driven Latent Variable Approach to Validating the Research Domain Criteria Framework.

Despite the widespread use of the Research Domain Criteria (RDoC) framework in psychiatry and neuroscience, recent studies suggest that the RDoC is insufficiently specific or excessively broad relative to the underlying brain circuitry it seeks to elucidate. To address these concerns of the RDoC framework, our study employed a latent variable approach, specifically utilizing bifactor analysis. We examined a total of 84 whole-brain task-based fMRI (tfMRI) activation maps from 19 studies with a total of 6,192 participants. Within this set of 84 maps, a curated subset of 37 maps with a balanced representation of RDoC domains constituted the training set of our analysis, and the remaining held-out maps formed the internal validation set. External validation was performed with 36 peak coordinate activation maps from Neurosynth, using terms of RDoC constructs as seeds for topic meta-analysis. Our results indicate that a bifactor model with a task-general domain and splitting the cognitive systems domain into sub-domains better fits the current corpus of tfMRI data than the current RDoC framework. Our data-driven validation supports revising the RDoC framework to accurately reflect underlying brain circuitry.

Behavioral activation system moderates self-referent processing following recovery from depression.

BACKGROUND: Previous research has implicated the behavioral activation system (BAS) in depression. The relationship of BAS functioning to aspects of cognitive vulnerability to depression, however, is not known. Method The present study investigated associations among level of BAS functioning and the encoding and recall of positive and negative self-referent information in currently non-depressed participants with a history of recurrent major depression (recovered; RMD) and in never-depressed control participants (CTL). Participants completed self-report measures of levels of BAS and behavioral inhibition system (BIS) functioning. Following a negative mood induction, participants were presented with a series of positive and negative adjectives; they indicated which words described them and later recalled as many of the words as they were able. RESULTS: The relationship of BAS functioning to self-referent processing was dependent on participant group. Although lower BAS reward responsivity was associated with the endorsement and recall of fewer positive words across groups, the magnitude of these associations was stronger, and was only significant, within the RMD group. Furthermore, only for RMD participants was lower BAS reward responsivity associated with the endorsement of more negative words. These effects were not accounted for by depressive or anxiety symptoms, current mood, or level of BIS functioning. CONCLUSIONS: These results indicate that BAS functioning may be distinctively linked to negatively biased self-referent processing, one facet of cognitive vulnerability to depression, in individuals with a history of major depressive disorder. Enhancing BAS functioning may be important in buffering cognitive vulnerability to depression.

Investigating neural primacy in Major Depressive Disorder: multivariate Granger causality analysis of resting-state fMRI time-series data.

Major Depressive Disorder (MDD) has been conceptualized as a neural network-level disease. Few studies of the neural bases of depression, however, have used analytical techniques that are capable of testing network-level hypotheses of neural dysfunction in this disorder. Moreover, of those that have, fewer still have attempted to determine the directionality of influence within functionally abnormal networks of structures. We used multivariate GC analysis, a technique that estimates the extent to which preceding neural activity in one or more seed regions predicts subsequent activity in target brain regions, to analyze blood-oxygen-level-dependent (BOLD) data collected during eyes-closed rest from depressed and never-depressed persons. We found that activation in the hippocampus predicted subsequent increases in ventral anterior cingulate cortex (vACC) activity in depression, and that activity in the medial prefrontal cortex and vACC were mutually reinforcing in MDD. Hippocampal and vACC activation in depressed participants predicted subsequent decreases in dorsal cortical activity. This study shows that, on a moment-by-moment basis, there is increased excitatory activity among limbic and paralimbic structures, as well as increased inhibition in the activity of dorsal cortical structures, by limbic structures in depression; these aberrant patterns of effective connectivity implicate disturbances in the mesostriatal dopamine system in depression. These findings advance the neural theory of depression by detailing specific patterns of limbic excitation in MDD, by making explicit the primary role of limbic inhibition of dorsal cortex in the cortico-limbic relation posited to underlie depression, and by presenting an integrated neurofunctional account of altered dopamine function in this disorder.

Specificity of cognitive biases in patients with current depression and remitted depression and in patients with asthma.

BACKGROUND: Previous studies have demonstrated a specific cognitive bias for sad stimuli in currently depressed patients; little is known, however, about whether this bias persists after recovery from the depressive episode. Depression is frequently observed in patients with asthma and is associated with a worse course of the disease. Given these high rates of co-morbidity, we could expect to observe a similar bias towards sad stimuli in patients with asthma. METHOD: We therefore examined cognitive biases in memory and attention in 20 currently and 20 formerly depressed participants, 20 never-depressed patients diagnosed with asthma, and 20 healthy control participants. All participants completed three cognitive tasks: the self-referential encoding and incidental recall task, the emotion face dot-probe task and the emotional Stroop task. RESULTS: Compared with healthy participants, currently and formerly depressed participants, but not patients with asthma, exhibited specific biases for sad stimuli. CONCLUSIONS: These results suggest that cognitive biases are evident in depression even after recovery from an acute episode but are not found in never-depressed patients with asthma.

Amygdala volume in major depressive disorder: a meta-analysis of magnetic resonance imaging studies.

Major depressive disorder has been associated with volumetric abnormality in the amygdala. In this meta-analysis we examine results from magnetic resonance imaging volumetry studies of the amygdala in depression in order to assess both the nature of the relationship between depression and amygdala volume as well as the influence of extraexperimental factors that may account for significant variability in reported findings. We searched PubMed and ISI Web of Knowledge databases for articles published from 1985 to 2008 that used the wildcard terms 'Depress*' and 'Amygdal*' in the title, keywords or abstract. From the 13 studies that met inclusion criteria for our meta-analysis, we calculated aggregate effect size and heterogeneity estimates from amygdala volumetric data; we then used meta-regression to determine whether variability in specific extraexperimental factors accounted for variability in findings. The lack of a reliable difference in amygdala volume between depressed and never-depressed individuals was accounted for by a positive correlation between amygdala volume differences and the proportion of medicated depressed persons in study samples: whereas the aggregate effect size calculated from studies that included only medicated individuals indicated that amygdala volume was significantly increased in depressed relative to healthy persons, studies with only unmedicated depressed individuals showed a reliable decrease in amygdala volume in depression. These findings are consistent with a formulation in which an antidepressant-mediated increase in levels of brain-derived neurotrophic factor promotes neurogenesis and protects against glucocorticoid toxicity in the amygdala in medicated but not in unmedicated depression.

Accelerated DNA methylation age in adolescent girls: associations with elevated diurnal cortisol and reduced hippocampal volume.

Numerous studies have linked exposure to stress to adverse health outcomes through the effects of cortisol, a product of the stress response system, on cellular aging processes. Accelerated DNA methylation age is a promising epigenetic marker associated with stress and disease risk that may constitute a link from stress response to changes in neural structures. Specifically, elevated glucocorticoid signaling likely contributes to accelerating DNA methylation age, which may signify a maladaptive stress-related cascade that leads to hippocampal atrophy. We examined the relations among diurnal cortisol levels, DNA methylation age and hippocampal volume in a longitudinal study of 46 adolescent girls. We computed area under the curve from two daily cortisol collection periods, and calculated DNA methylation age using previously established methods based on a set of CpG sites associated with chronological age. We computed a residual score by partialling out chronological age; higher discrepancies reflect relatively accelerated DNA methylation age. We assessed hippocampal volume via T1-weighted images and automated volumetric segmentation. We found that greater diurnal cortisol production was associated with accelerated DNA methylation age, which in turn was associated with reduced left hippocampal volume. Finally, accelerated DNA methylation age significantly mediated the association between diurnal cortisol and left hippocampal volume. Thus, accelerated DNA methylation age may be an epigenetic marker linking hypothalamic-pituitary-adrenal axis dysregulation with neural structure. If these findings are replicated, the current study provides a method for advancing our understanding of mechanisms by which glucocorticoid signaling is associated with cellular aging and brain development.

Clinical status and emotional adjustment of children of depressed mothers.

The authors compared children (ages 7-13 years) of unipolar depressed mothers with children of nondepressed psychiatric patients, of nondepressed medical patients, and of nondepressed mothers in the community. The children's adjustment was rated by clinicians on the Child Adjustment Schedule and by the mothers on the Child Behavior Checklist. The highest proportion of clinically significant problems was found in the children of the depressed mothers. However, the overlap between the problems of these children and those of the children of the nondepressed psychiatric patients calls into question the formulation that children's adjustment difficulties are specific to parental depression.

Natural course of adolescent major depressive disorder in a community sample: predictors of recurrence in young adults.

OBJECTIVE: The primary purpose was to identify factors related to the recurrence of major depressive disorder during young adulthood (19-23 years of age) in a community sample of formerly depressed adolescents. METHOD: A total of 274 participants with adolescent-onset major depressive disorder were assessed twice during adolescence and again after their 24th birthday. Lifetime psychiatric information was obtained from their first-degree relatives. Adolescent predictor variables included demographic characteristics, psychosocial variables, characteristics of adolescent major depressive disorder, comorbidity, family history of major depressive disorder and nonmood disorder, and antisocial and borderline personality disorder symptoms. RESULTS: Low levels of excessive emotional reliance, a single episode of major depressive disorder in adolescence, low proportion of family members with recurrent major depressive disorder, low levels of antisocial and borderline personality disorder symptoms, and a positive attributional style (males only) independently predicted which formerly depressed adolescents would remain free of future psychopathology. Female gender, multiple major depressive disorder episodes in adolescence, higher proportion of family members with recurrent major depressive disorder, elevated borderline personality disorder symptoms, and conflict with parents (females only) independently predicted recurrent major depressive disorder. Comorbid anxiety and substance use disorders in adolescence and elevated antisocial personality disorder symptoms independently distinguished adolescents who developed recurrent major depressive disorder comorbid with nonmood disorder from those who developed pure major depressive disorder. CONCLUSIONS: Formerly depressed adolescents with the risk factors identified in this study are at elevated risk for recurrence of major depressive disorder during young adulthood and therefore warrant continued monitoring and preventive or prophylactic treatment.

Psychopathology and early experience: a reappraisal of retrospective reports.

Three potential sources of error in retrospective reports of childhood experiences are documented: low reliability and validity of autobiographical memory in general, the presence of general memory impairment associated with psychopathology, and the presence of specific mood-congruent memory biases associated with psychopathology. The evidence reviewed suggests that claims concerning the general unreliability of retrospective reports are exaggerated and that there is little reason to link psychiatric status with less reliable or less valid recall of early experiences. Nevertheless, it is clear that steps must be taken to overcome the limitations of retrospective reports and enhance their reliability.

Risk for psychopathology in the children of depressed mothers: a developmental model for understanding mechanisms of transmission.

A large body of literature documents the adverse effects of maternal depression on the functioning and development of offspring. Although investigators have identified factors associated with risk for abnormal development and psychopathology in the children, little attention has been paid to the mechanisms explaining the transmission of risk from the mothers to the children. Moreover, no existing model both guides understanding of the various processes' interrelatedness and considers the role of development in explicating the manifestation of risk in the children. This article proposes a developmentally sensitive, integrative model for understanding children's risk in relation to maternal depression. Four mechanisms through which risk might be transmitted are evaluated: (a) heritability of depression; (b) innate dysfunctional neuroregulatory mechanisms; (c) exposure to negative maternal cognitions, behaviors, and affect; and (d) the stressful context of the children's lives. Three factors that might moderate this risk are considered: (a) the father's health and involvement with the child, (b) the course and timing of the mother's depression, and (c) characteristics of the child. Relevant issues are discussed, and promising directions for future research are suggested.

Adolescent psychopathology: IV. Specificity of psychosocial risk factors for depression and substance abuse in older adolescents.

OBJECTIVE: To determine the specificity to major depressive disorder (MDD) of a wide array of psychosocial risk factors in older adolescents (aged 14 through 18 years). METHOD: Diagnostic and psychosocial assessments were conducted with 1,507 randomly selected high school students at T1 and after approximately 1 year (T2). Three diagnostic groups were compared: those who had an episode of MDD during that year (n = 90), those who had an episode of substance use disorder during that year (SUD) (n = 42), and a control group with no disorder (n = 1,189). RESULTS: Risk factors specific to MDD were stress (minor and major events), emotional reliance, physical symptoms and disease, history of suicide attempt, and a past episode of depression or anxiety disorder. Risk factors specific to SUD were tobacco use, academic difficulties, and a past episode of SUD. Risk factors that were shared were current depression symptoms, internalizing and externalizing behavior problems, coping skills, interpersonal conflict with parents, and dissatisfaction with grades. CONCLUSIONS: By determining the number of risk factors for MDD, for SUD, or those that are general to both disorders, clinicians can make informed predictions concerning the probable future onset of a full-fledged episode of MDD and/or SUD in individual cases. The results of this study allow for the identification of adolescents who are at elevated risk for MDD and SUD. The results also have implications for the design of interventions aimed at preventing the occurrence of these disorders. Such interventions should target change on risk factors of the type identified in this study.

Comparison of postpartum and nonpostpartum depression: clinical presentation, psychiatric history, and psychosocial functioning.

This study compared a sample of postpartum women diagnosed with depression with a nonpostpartum depressed group and 2 nondepressed control groups. Women's depressive episodes were compared to determine whether differences existed in symptomatology, previous history, or course. Results indicate that postpartum depression tends to be relatively mild. Both depressed groups had high rates of positive psychiatric history and were equally likely to have recovered at a 6-month follow-up. Groups were also compared on psychosocial variables known to covary with depression: interpersonal relations, stress, and coping. A series of multivariate analyses of covariance showed few differences between the depressed groups that were not attributable to symptom severity, although postpartum depressed women did report better marital relations than did the nonpostpartum depressed women. These findings suggest that there is little to distinguish postpartum from nonpostpartum depression beyond differences in symptom severity.

Symptoms versus a diagnosis of depression: differences in psychosocial functioning.

In studies of clinical depression, individuals who demonstrate elevated levels of symptoms but do not meet interview-based diagnostic criteria are typically labeled as false positive and eliminated from further consideration. However, the implicit assumption that false-positive participants differ in important ways from true-positive (i.e., diagnosed) participants has not been tested systematically. This study compared the functioning of true-positive, false-positive, and true-negative adolescents on clinical and psychosocial functioning. Although the false-positive participants manifested higher levels of current and future psychopathology than did the true-negative participants, they did not differ significantly from the true-positive participants on most of the measures of psychosocial dysfunction. "False positive," therefore, is not a benign condition.

Prevalence rates and demographic characteristics associated with depression in pregnancy and the postpartum.

Examined the prevalence of depression in a heterogeneous sample of 360 pregnant women. Subjects were assessed with respect to both depressive symptomatology and diagnostic status during pregnancy and after delivery. At both assessments, approximately 25% of the sample reported elevated levels of depressive symptomatology. In contrast, 10% of the women met diagnostic criteria for depression during pregnancy, and 6.8% were depressed postpartum. However, only half of the cases of postpartum depression were new onset (3.4%); the remaining women receiving a diagnosis in the postpartum had also been depressed during pregnancy. Finally, depression during pregnancy was related to different sociodemographic variables than was postpartum depression, suggesting that depression at these two times may be associated with different psychological or etiological factors.

Selective attention and clinical depression: performance on a deployment-of-attention task.

Clinically depressed and nondepressed individuals completed a deployment-of-attention task developed by I. H. Gotlib, A. L. McLachlan, and A. N. Katz (1988). Results indicated that the clinically depressed individuals perform the task in an unbiased fashion, attending equally to positive-, negative-, and neutral-content stimuli. In contrast, the nondepressed individuals demonstrated a "protective" bias against the perception of negative stimuli by avoiding such material in favor of positive or neutral stimuli. Overall, the results of this study suggest that clinically depressed individuals do not show an attentional bias toward negative information, but rather, fail to demonstrate the positive or protective bias that is evident in nondepressed individuals.