Neural systems underlying thought suppression in young women with, and at-risk, for depression

Abnormal caudate nucleus activity in patients with depressive disorder: Meta-analysis of task-based functional magnetic resonance imaging studies with behavioral domain

During task-based functional magnetic resonance imaging (t-fMRI) patients with depressive disorder (DD) have shown abnormal caudate nucleus activation. There have been no meta-analyses that are conducted on the caudate nucleus using Activation Likelihood Estimation (ALE) in patients with DD, and the relationships between abnormal caudate activity and different behavior domains in patients with DD remain unclear. There were 24 previously published t-fMRI studies included in the study with the caudate nucleus as the region of interest. Meta-analyses were performed using the method of ALE. Included five ALE meta-analyses: (1) the hypoactivated caudate nucleus relative to healthy controls (HCs); (2) the hyper-activated caudate nucleus; (3) the abnormal activation in the caudate nucleus in the emotion domain; (4) the abnormal activation in cognition domain; (5) the abnormal activation in the affective cognition domain. Results revealed that the hypo-/hyper-activity in the caudate subregions is mainly located in the caudate body and head, while the relationships between abnormal caudate subregions and different behavior domains are complex. The hypoactivation of the caudate body and head plays a key role in the emotions which indicates there is a positive relationship between the decreased caudate activity and depressed emotional behaviors in patients with DD.

Graph theoretical measures of the uncinate fasciculus subnetwork as predictors and correlates of treatment response in a transdiagnostic psychiatric cohort

The internalizing psychopathologies (IP) are a highly prevalent group of disorders for which little data exists to guide treatment selection. We examine whether graph theoretical metrics from white matter connectomes may serve as biomarkers of disease and predictors of treatment response. We focus on the uncinate fasciculus subnetwork, which has been previously implicated in these disorders. We compared baseline graph measures from a transdiagnostic IP cohort with controls. Patients were randomized to either SSRI or cognitive behavioral therapy and we determined if graph theory metrics change following treatment, and whether these changes correlated with treatment response. Lastly, we investigated whether baseline metrics correlated with treatment response. Several baseline nodal graph metrics differed at baseline. Of note, right amygdala betweenness centrality was increased in patients relative to controls. In addition, white matter integrity of the uncinate fasciculus was decreased at baseline in patients versus controls. The SSRI and CBT cohorts had increased left frontal superior orbital betweenness centrality and left frontal medial orbital clustering coefficient, respectively, suggesting the presence of treatment specific neural correlates of treatment response. This study provides insight on shared white matter network features of IPs and elucidates potential biomarkers of treatment response that may be modality-specific.

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.

Can't get it off my brain: Meta-analysis of neuroimaging studies on perseverative cognition

Perseverative cognition (i.e. rumination and worry) describes intrusive, uncontrollable, repetitive thoughts. These negative affective experiences are accompanied by physiological arousal, as if the individual were facing an external stressor. Perseverative cognition is a transdiagnostic symptom, yet studies of neural mechanisms are largely restricted to specific clinical populations (e.g. patients with major depression). The present study applied activation likelihood estimation (ALE) meta-analyses to 43 functional neuroimaging studies of perseverative cognition to elucidate the neurobiological substrates across individuals with and without psychopathological conditions. Task-related and resting state functional connectivity studies were examined in separate meta-analyses. Across task-based studies, perseverative cognition engaged medial frontal gyrus, cingulate gyrus, insula, and posterior cingulate cortex. Resting state functional connectivity studies similarly implicated posterior cingulate cortex together with thalamus and anterior cingulate cortex (ACC), yet the involvement of ACC distinguished between perseverative cognition in healthy controls (HC) and clinical groups. Perseverative cognition is accompanied by the engagement of prefrontal, insula and cingulate regions, whose interaction may support the characteristic conjunction of self-referential and affective processing with (aberrant) cognitive control and embodied (autonomic) arousal. Within this context, ACC engagement appears critical for the pathological expression of rumination and worry.

Candidate Biomarkers of Suicide Crisis Syndrome: What to Test Next? A Concept Paper

BACKGROUND

There has been increasing interest in both suicide-specific diagnoses within the psychiatric nomenclature and related biomarkers. Because the Suicide Crisis Syndrome-an emotional crescendo of several interrelated symptoms-seems to be promising for the identification of individuals at risk of suicide, the aim of the present paper is to review the putative biological underpinnings of the Suicide Crisis Syndrome symptoms (entrapment, affective disturbance, loss of cognitive control, hyperarousal, social withdrawal).

METHODS

A PubMed literature search was performed to identify studies reporting a link between each of the 5 Suicide Crisis Syndrome symptoms and biomarkers previously reported to be associated with suicidal outcomes.

RESULTS

Disturbances in the hypothalamic-pituitary-adrenal axis, with dysregulated corticotropin-releasing hormone and cortisol levels, may be linked to a sense of entrapment. Affective disturbance is likely mediated by alterations in dopaminergic circuits involved in reward and antireward systems as well as endogenous opioids. Loss of cognitive control is linked to altered neurocognitive function in the areas of executive function, attention, and decision-making. Hyperarousal is linked to autonomic dysregulation, which may be characterized by a reduction in both heart rate variability and electrodermal activity. Social withdrawal has been associated with oxytocin availability. There is also evidence that inflammatory processes may contribute to individual Suicide Crisis Syndrome symptoms.

CONCLUSION

The Suicide Crisis Syndrome is a complex syndrome that is likely the consequence of distinct changes in interconnected neural, neuroendocrine, and autonomic systems. Available clinical and research data allow for development of empirically testable hypotheses and experimental paradigms to scrutinize the biological substrates of the Suicide Crisis Syndrome.

Neural predictors of emotional inertia in daily life

Assessing emotional dynamics in the brain offers insight into the fundamental neural and psychological mechanisms underlying emotion. One such dynamic is emotional inertia-the influence of one's emotional state at one time point on one's emotional state at a subsequent time point. Emotion inertia reflects emotional rigidity and poor emotion regulation as evidenced by its relationship to depression and neuroticism. In this study, we assessed changes in cerebral blood flow (CBF) from before to after an emotional task and used these changes to predict stress, positive and negative emotional inertia in daily life events. Cerebral blood flow changes in the lateral prefrontal cortex (lPFC) predicted decreased non-specific emotional inertia, suggesting that the lPFC may feature a general inhibitory mechanism responsible for limiting the impact that an emotional state from one event has on the emotional state of a subsequent event. CBF changes in the ventromedial prefrontal cortex and lateral occipital cortex were associated with positive emotional inertia and negative/stress inertia, respectively. These data advance the blossoming literature on the temporal dynamics of emotion in the brain and on the use of neural indices to predict mental health-relevant behavior in daily life.

Adolescent Gender Differences in Cognitive Control Performance and Functional Connectivity Between Default Mode and Fronto-Parietal Networks Within a Self-Referential Context

Ineffective reduction of functional connectivity between the default mode network (DMN) and frontoparietal network (FPN) during cognitive control can interfere with performance in healthy individuals—a phenomenon present in psychiatric disorders, such as depression. Here, this mechanism is studied in healthy adolescents by examining gender differences in task-regressed functional connectivity using functional magnetic resonance imaging (MRI) and a novel task designed to place the DMN—supporting self-referential processing (SRP)—and FPN—supporting cognitive control—into conflict. Compared to boys, girls showed stronger functional connectivity between DMN and FPN during cognitive control in an SRP context (n = 40; boys = 20), a context that also elicited more errors of omission in girls. The gender difference in errors of omission was mediated by higher self-reported co-rumination—the extensive and repetitive discussion of problems and focus on negative feelings with a same-gender peer—by girls, compared to boys. These findings indicate that placing internal and external attentional demands in conflict lead to persistent functional connectivity between FPN and DMN in girls, but not boys; however, deficits in performance during this context were explained by co-rumination, such that youth with higher co-rumination displayed the largest performance deficits. Previous research shows that co-rumination predicts depressive symptoms during adolescence; thus, gender differences in the mechanisms involved with transitioning from internal to external processing may be relevant for understanding heightened vulnerability for depression in adolescent girls.

Reduced fronto-amygdalar connectivity in adolescence is associated with increased depression symptoms over time

Depression is common among adolescents, affecting greater than 12% of youth in a given year. Studies have shown aberrant amygdala connectivity in depressed adolescents, compared with controls; however, no studies have examined whether these abnormalities precede and heighten risk for depressive symptom expression. This study used resting state functional connectivity (RSFC) magnetic resonance imaging to examine neurobiological markers of escalating depression symptoms in adolescents (ages 12-16 years; free from psychopathology at baseline). Of a large sample of adolescents, 18 showed ≥ 1 S.D. increase in depression scale t-scores over time ("escalators"; time to escalation ranging from 6 to 54 months in follow up) and were matched and compared to 19 youth showing stable CDI scores over time ("controls"). Whole-brain analyses on baseline RSFC data using an amygdala seed region-of-interest (ROI) showed that controls had greater RSFC, relative to escalators, between the right amygdala and left inferior frontal and supramarginal gyrus and right mid-cingulate cortex. Additionally, relative to escalators, control youth had less RSFC between the left amygdala and cerebellum. Findings suggest a possible neurobiological marker of increasing depressive symptoms during adolescence, characterized in part by reduced fronto-limbic connectivity, suggesting a premorbid deficiency in top-down emotional regulation.

Differential association of default mode network connectivity and rumination in healthy individuals and remitted MDD patients

Rumination is associated with increased default-mode network (DMN) activity and functional connectivity (FC) in depressed and healthy individuals. In this study, we sought to examine the relationship between self-reported rumination and resting-state FC in the DMN and cognitive control networks in 25 remitted depressed patients and 25 matched healthy controls using independent component and seed-based analyses. We also explored potential group differences in the global pattern of resting-state FC. Healthy subjects with increased levels of rumination exhibited increased anterior DMN connectivity with the posterior DMN and the dorsal attention network and low connectivity within the anterior DMN. On the other hand, remitted depressed ruminators patients were associated with the opposite FC pattern in these regions. Based on global FC patterns, a support vector machine algorithm correctly classified 92% of the subjects into their respective group by a leave-one-out cross-validation. Whole-brain FC analysis also revealed a group by rumination interaction effect within the DMN. The present findings highlight the different functional roles of the anterior and the posterior DMN, and provide novel insights into the underlying neural mechanisms leading to depression relapse.

Reductions in Cortico-Striatal Hyperconnectivity Accompany Successful Treatment of Obsessive-Compulsive Disorder with Dorsomedial Prefrontal rTMS

Obsessive-compulsive disorder (OCD) is a disabling illness with high rates of nonresponse to conventional treatments. OCD pathophysiology is believed to involve abnormalities in cortico-striatal-thalamic-cortical circuits through regions such as dorsomedial prefrontal cortex (dmPFC) and ventral striatum. These regions may constitute therapeutic targets for neuromodulation treatments, such as repetitive transcranial magnetic stimulation (rTMS). However, the neurobiological predictors and correlates of successful rTMS treatment for OCD are unclear. Here, we used resting-state functional magnetic resonance imaging (fMRI) to identify neural predictors and correlates of response to 20-30 sessions of bilateral 10 Hz dmPFC-rTMS in 20 treatment-resistant OCD patients, with 40 healthy controls as baseline comparators. A region of interest in the dmPFC was used to generate whole-brain functional connectivity maps pre-treatment and post treatment. Ten of 20 patients met the response criteria (⩾50% improvement on Yale-Brown Obsessive-Compulsive Scale, YBOCS); response to dmPFC-rTMS was sharply bimodal. dmPFC-rTMS responders had higher dmPFC-ventral striatal connectivity at baseline. The degree of reduction in this connectivity, from pre- to post-treatment, correlated to the degree of YBOCS symptomatic improvement. Baseline clinical and psychometric data did not predict treatment response. In summary, reductions in fronto-striatal hyperconnectivity were associated with treatment response to dmPFC-rTMS in OCD. This finding is consistent with previous fMRI studies of deep brain stimulation in OCD, but opposite to previous reports on mechanisms of dmPFC-rTMS in major depression. fMRI could prove useful in predicting the response to dmPFC-rTMS in OCD.

Design and Implementation of an fMRI Study Examining Thought Suppression in Young Women with, and At-risk, for Depression

Ruminative brooding is associated with increased vulnerability to major depression. Individuals who regularly ruminate will often try to reduce the frequency of their negative thoughts by actively suppressing them. We aim to identify the neural correlates underlying thought suppression in at-risk and depressed individuals. Three groups of women were studied; a major depressive disorder group, an at-risk group (having a first degree relative with depression) and controls. Participants performed a mixed block-event fMRI paradigm involving thought suppression, free thought and motor control periods. Participants identified the re-emergence of "to-be-suppressed" thoughts ("popping" back into conscious awareness) with a button press. During thought suppression the control group showed the greatest activation of the dorsolateral prefrontal cortex, followed by the at-risk, then depressed group. During the re-emergence of intrusive thoughts compared to successful re-suppression of those thoughts, the control group showed the greatest activation of the anterior cingulate cortices, followed by the at-risk, then depressed group. At-risk participants displayed anomalies in the neural regulation of thought suppression resembling the dysregulation found in depressed individuals. The predictive value of these changes in the onset of depression remains to be determined.

Imbalance of default mode and regulatory networks during externally focused processing in depression

Attentional control difficulties likely underlie rumination, a core cognitive vulnerability in major depressive disorder (MDD). Abnormalities in the default mode, executive and salience networks are implicated in both rumination and attentional control difficulties in MDD. In the current study, individuals with MDD (n = 16) and healthy controls (n = 16) completed tasks designed to elicit self-focused (ruminative) and externally-focused thinking during fMRI scanning. The MDD group showed greater default mode network connectivity and less executive and salience network connectivity during the external-focus condition. Contrary to our predictions, there were no differences in connectivity between the groups during the self-focus condition. Thus, it appears that when directed to engage in self-referential thinking, both depressed and non-depressed individuals similarly recruit networks supporting this process. In contrast, when instructed to engage in non-self-focused thought, non-depressed individuals show a pattern of network connectivity indicative of minimized self-referential processing, whereas depressed individuals fail to reallocate neural resources in a manner consistent with effective down regulation of self-focused thought. This is consistent with difficulties in regulating self-focused thinking in order to engage in more goal-directed behavior that is seen in individuals with MDD.