Knut Schnell

Subcortical brain alterations in major depressive disorder: findings from the ENIGMA Major Depressive Disorder working group.

The pattern of structural brain alterations associated with major depressive disorder (MDD) remains unresolved. This is in part due to small sample sizes of neuroimaging studies resulting in limited statistical power, disease heterogeneity and the complex interactions between clinical characteristics and brain morphology. To address this, we meta-analyzed three-dimensional brain magnetic resonance imaging data from 1728 MDD patients and 7199 controls from 15 research samples worldwide, to identify subcortical brain volumes that robustly discriminate MDD patients from healthy controls. Relative to controls, patients had significantly lower hippocampal volumes (Cohen’s d=−0.14, % difference=−1.24). This effect was driven by patients with recurrent MDD (Cohen’s d=−0.17, % difference=−1.44), and we detected no differences between first episode patients and controls. Age of onset ⩽21 was associated with a smaller hippocampus (Cohen’s d=−0.20, % difference=−1.85) and a trend toward smaller amygdala (Cohen’s d=−0.11, % difference=−1.23) and larger lateral ventricles (Cohen’s d=0.12, % difference=5.11). Symptom severity at study inclusion was not associated with any regional brain volumes. Sample characteristics such as mean age, proportion of antidepressant users and proportion of remitted patients, and methodological characteristics did not significantly moderate alterations in brain volumes in MDD. Samples with a higher proportion of antipsychotic medication users showed larger caudate volumes in MDD patients compared with controls. This currently largest worldwide effort to identify subcortical brain alterations showed robust smaller hippocampal volumes in MDD patients, moderated by age of onset and first episode versus recurrent episode status.

Cortical abnormalities in adults and adolescents with major depression based on brain scans from 20 cohorts worldwide in the ENIGMA Major Depressive Disorder Working Group

The neuro-anatomical substrates of major depressive disorder (MDD) are still not well understood, despite many neuroimaging studies over the past few decades. Here we present the largest ever worldwide study by the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Major Depressive Disorder Working Group on cortical structural alterations in MDD. Structural T1-weighted brain magnetic resonance imaging (MRI) scans from 2148 MDD patients and 7957 healthy controls were analysed with harmonized protocols at 20 sites around the world. To detect consistent effects of MDD and its modulators on cortical thickness and surface area estimates derived from MRI, statistical effects from sites were meta-analysed separately for adults and adolescents. Adults with MDD had thinner cortical gray matter than controls in the orbitofrontal cortex (OFC), anterior and posterior cingulate, insula and temporal lobes (Cohen’s d effect sizes: −0.10 to −0.14). These effects were most pronounced in first episode and adult-onset patients (>21 years). Compared to matched controls, adolescents with MDD had lower total surface area (but no differences in cortical thickness) and regional reductions in frontal regions (medial OFC and superior frontal gyrus) and primary and higher-order visual, somatosensory and motor areas (d: −0.26 to −0.57). The strongest effects were found in recurrent adolescent patients. This highly powered global effort to identify consistent brain abnormalities showed widespread cortical alterations in MDD patients as compared to controls and suggests that MDD may impact brain structure in a highly dynamic way, with different patterns of alterations at different stages of life.

Effect of Disorder-Specific vs Nonspecific Psychotherapy for Chronic Depression: A Randomized Clinical Trial

Importance Chronic depression is a highly prevalent and disabling disorder. There is a recognized need to assess the value of long-term disorder-specific psychotherapy. Objective To evaluate the efficacy of the Cognitive Behavioral Analysis System of Psychotherapy (CBASP) compared with that of nonspecific supportive psychotherapy (SP). Design, Setting, and Participants A prospective, multicenter, evaluator-blinded, randomized clinical trial was conducted among adult outpatients with early-onset chronic depression who were not taking antidepressant medication. Patients were recruited between March 5, 2010, and October 16, 2012; the last patient finished treatment on October 14, 2013. Data analysis was conducted from March 5, 2014, to October 27, 2016. Interventions The treatment included 24 sessions of CBASP or SP for 20 weeks in the acute phase, followed by 8 continuation sessions during the next 28 weeks. Main Outcomes and Measures The primary outcome was symptom severity after 20 weeks (blinded observer ratings) as assessed by the 24-item Hamilton Rating Scale for Depression (HRSD-24). Secondary outcomes were rates of response (reduction in HRSD-24 score of ≥50% from baseline) and remission (HRSD-24 score ⩽8), as well as self-assessed ratings of depression, global functioning, and quality of life. Results Among 622 patients assessed for eligibility, 268 were randomized: 137 to CBASP (96 women [70.1%] and 41 men [29.9%]; mean [SD] age, 44.7 [12.1] years) and 131 to SP (81 women [61.8%] and 50 men [38.2%]; mean [SD] age, 45.2 [11.6] years). The mean (SD) baseline HRSD-24 scores of 27.15 (5.49) in the CBASP group and 27.05 (5.74) in the SP group improved to 17.19 (10.01) and 20.39 (9.65), respectively, after 20 weeks, with a significant adjusted mean difference of –2.51 (95% CI, –4.16 to –0.86; Pu2009=u2009.003) and a Cohen d of 0.31 in favor of CBASP. After 48 weeks, the HRSD-24 mean (SD) scores were 14.00 (9.72) for CBASP and 16.49 (9.96) for SP, with an adjusted difference of –3.13 (95% CI, –5.01 to –1.25; Pu2009=u2009.001) and a Cohen d of 0.39. Patients undergoing CBASP were more likely to reach response (48 of 124 [38.7%] vs 27 of 111 [24.3%]; adjusted odds ratio, 2.02; 95% CI, 1.09 to 3.73; Pu2009=u2009.03) or remission (27 of 124 [21.8%] vs 14 of 111 [12.6%]; adjusted odds ratio, 3.55; 95% CI, 1.61 to 7.85; Pu2009=u2009.002) after 20 weeks. Patients undergoing CBASP showed significant advantages in most other secondary outcomes. Conclusions and Relevance Highly structured specific psychotherapy was moderately more effective than nonspecific therapy in outpatients with early-onset chronic depression who were not taking antidepressant medication. Adding an extended phase to acute psychotherapy seems promising in this population. Trial Registration clinicaltrials.gov Identifier: NCT00970437.

Cognitive Behavioral Analysis System of Psychotherapy versus Escitalopram in Chronic Major Depression

Background: A specific psychotherapy for chronic depression, the Cognitive Behavioral Analysis System of Psychotherapy (CBASP), was compared to escitalopram (ESC). Methods: Sixty patients with chronic major depression were randomized to ‘CBASP (22 sessions) or ‘ESC plus clinical management (ESC/CM) at two treatment sites. The primary outcome measure was the score on the Montgomery-Asberg Depression Rating Scale (MADRS) after 8 weeks of acute treatment assessed by blinded raters. In the case of nonimprovement (<20% reduction in the MADRS score), the other condition was augmented for the following 20 weeks of extended treatment. Secondary end points were, among others, depressive symptoms, remission (MADRS score of ≤9) and response rates (reduction of MADRS score of ≥50%) 28 weeks after randomization. Results: An intent-to-treat analysis revealed that clinician-rated depression scores decreased significantly after 8 and 28 weeks with no significant differences between the groups. The response rates after 28 weeks of treatment were high (CBASP: 68.4%, ESC/CM: 60.0%), and the remission rates were moderate (CBASP: 36.8%, ESC/CM: 50.0%) with neither group being superior. Nonimprovers to the initial treatment caught up with the initial improvers in terms of depression scores and response and remission rates by the end of the treatment after being augmented with the respective other condition. Conclusions: CBASP and ESC/CM appear to be equally effective treatment options for chronically depressed outpatients. For nonimprovers to the initial treatment, it is efficacious to augment with medication in the case of nonresponse to CBASP and vice versa.

Subcortical brain structure and suicidal behaviour in major depressive disorder: a meta-analysis from the ENIGMA-MDD working group

The aetiology of suicidal behaviour is complex, and knowledge about its neurobiological mechanisms is limited. Neuroimaging methods provide a noninvasive approach to explore the neural correlates of suicide vulnerability in vivo. The ENIGMA-MDD Working Group is an international collaboration evaluating neuroimaging and clinical data from thousands of individuals collected by research groups from around the world. Here we present analyses in a subset sample (n=3097) for whom suicidality data were available. Prevalence of suicidal symptoms among major depressive disorder (MDD) cases ranged between 29 and 69% across cohorts. We compared mean subcortical grey matter volumes, lateral ventricle volumes and total intracranial volume (ICV) in MDD patients with suicidal symptoms (N=451) vs healthy controls (N=1996) or MDD patients with no suicidal symptoms (N=650). MDD patients reporting suicidal plans or attempts showed a smaller ICV (P=4.12 × 10−3) or a 2.87% smaller volume compared with controls (Cohen’s d=−0.284). In addition, we observed a nonsignificant trend in which MDD cases with suicidal symptoms had smaller subcortical volumes and larger ventricular volumes compared with controls. Finally, no significant differences (P=0.28–0.97) were found between MDD patients with and those without suicidal symptoms for any of the brain volume measures. This is by far the largest neuroimaging meta-analysis of suicidal behaviour in MDD to date. Our results did not replicate previous reports of association between subcortical brain structure and suicidality and highlight the need for collecting better-powered imaging samples and using improved suicidality assessment instruments.

Theory of mind network activity is altered in subjects with familial liability for schizophrenia

As evidenced by a multitude of studies, abnormalities in Theory of Mind (ToM) and its neural processing might constitute an intermediate phenotype of schizophrenia. If so, neural alterations during ToM should be observable in unaffected relatives of patients as well, since they share a considerable amount of genetic risk. While behaviorally, impaired ToM function is confirmed meta-analytically in relatives, evidence on aberrant function of the neural ToM network is sparse and inconclusive. The present study therefore aimed to further explore the neural correlates of ToM in relatives of schizophrenia. About 297 controls and 63 unaffected first-degree relatives of patients with schizophrenia performed a ToM task during functional magnetic resonance imaging. Consistent with the literature relatives exhibited decreased activity of the medial prefrontal cortex. Additionally, increased recruitment of the right middle temporal gyrus and posterior cingulate cortex was found, which was related to subclinical paranoid symptoms in relatives. These results further support decreased medial prefrontal activation during ToM as an intermediate phenotype of genetic risk for schizophrenia. Enhanced recruitment of posterior ToM areas in relatives might indicate inefficiency mechanisms in the presence of genetic risk.

Childhood adversity impacts on brain subcortical structures relevant to depression

Childhood adversity plays an important role for development of major depressive disorder (MDD). There are differences in subcortical brain structures between patients with MDD and healthy controls, but the specific impact of childhood adversity on such structures in MDD remains unclear. Thus, aim of the present study was to investigate whether childhood adversity is associated with subcortical volumes and how it interacts with a diagnosis of MDD and sex. Within the ENIGMA-MDD network, nine university partner sites, which assessed childhood adversity and magnetic resonance imaging in patients with MDD and controls, took part in the current joint mega-analysis. In this largest effort world-wide to identify subcortical brain structure differences related to childhood adversity, 3036 participants were analyzed for subcortical brain volumes using FreeSurfer. A significant interaction was evident between childhood adversity, MDD diagnosis, sex, and region. Increased exposure to childhood adversity was associated with smaller caudate volumes in females independent of MDD. All subcategories of childhood adversity were negatively associated with caudate volumes in females - in particular emotional neglect and physical neglect (independently from age, ICV, imaging site and MDD diagnosis). There was no interaction effect between childhood adversity and MDD diagnosis on subcortical brain volumes. Childhood adversity is one of the contributors to brain structural abnormalities. It is associated with subcortical brain abnormalities that are relevant to psychiatric disorders such as depression.

Behavioral Evidence for an Impairment of Affective Theory of Mind Capabilities in Chronic Depression

Background: The only treatment specifically developed for chronic depression, the Cognitive Behavioral Analysis System of Psychotherapy (CBASP), is based amongst others on the hypothesis that chronically depressed patients (CD) show considerable deficits of affective theory of mind (ToM) capabilities. Data are scarce, however, and it remains unclear if ToM deficits are specific or if they arise from global cognitive deficits associated with depression. This study investigates the specific deficits of affective ToM abilities in CD. Sampling and Methods: ToM abilities were assessed in 26 medication-free CD and 26 matched healthy controls (HC) by means of a previously established false-belief ToM cartoon task. Since the task allowed an intern control for cognitive factors - operationalized in a visuospatial ToM task - it was possible to investigate specific affective ToM deficits. Results: As hypothesized, the CD showed a significant specific slowdown of affective ToM compared to cognitive ToM (3rd person perspective) when compared to HC. Simultaneously, we observed a general deterioration of all ToM functions in CD. Conclusions: This study provides evidence that CD have a mentalization deficit, specifically for affective ToM functions. This deficit is combined with a general deterioration of ToM functions, most likely attributable to frequently described cognitive deficits in depression.

Functional Correlates of childhood maltreatment and symptom severity during affective theory of mind tasks in chronic depression

Among multiple etiological factors of depressive disorders, childhood maltreatment (CM) gains increasing attention as it confers susceptibility for depression and predisposes to chronicity. CM assumedly inhibits social-cognitive development, entailing interactional problems as observed in chronic depression (CD), especially in affective theory of mind (ToM). However, the extent of CM among CD patients varies notably as does the severity of depressive symptoms. We tested whether the extent of CM or depressive symptoms correlates with affective ToM functions in CD patients. Regional brain activation measured by functional magnetic resonance imaging during an affective ToM task was tested for correlation with CM, assessed by the Childhood Trauma Questionnaire (CTQ), and symptom severity, assessed by the Montgomery-Åsberg Depression Rating Scale (MADRS), in 25 unmedicated CD patients (mean age 41.52, SD 11.13). Amygdala activation during affective ToM correlated positively with CTQ total scores, while (para)hippocampal response correlated negatively with MADRS scores. Our findings suggest that differential amygdala activation in affective ToM in CD is substantially modulated by previous CM and not by the pathophysiological equivalents of current depressive symptoms. This illustrates the amygdalas role in the mediation of CM effects. The negative correlation of differential (para)hippocampal activation and depressive symptom severity indicates reduced integration of interactional experiences during depressive states.

Childhood trauma-related alterations in brain function during a Theory-of-Mind task in schizophrenia

Childhood trauma is a risk factor for schizophrenia that affects brain functions associated with higher cognitive processes, including social cognition. Alterations in Theory-of-Mind (ToM), or mentalizing skills, are a hallmark feature of schizophrenia, and are also evident in individuals exposed to childhood trauma. However, the impact of childhood trauma exposure on brain function during social cognition in schizophrenia remains unclear. We thus examined the association between childhood trauma and brain function during the performance of a ToM task in 47 patients diagnosed with schizophrenia or schizoaffective disorder. All participants completed the Childhood Trauma Questionnaire (CTQ) and underwent functional magnetic resonance imaging while performing an established visual-cartoon affective ToM task. Whole-brain multiple regression analysis was performed on ToM-related brain activation, with CTQ total score as regressor of interest, while accounting for the effects of age, sex, diagnosis, symptom severity, behavioural performance, intelligence and medications levels. First, using a small-volume correction approach within a mask made of key regions for ToM [including bilateral temporo-parietal junctions (TPJ), medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC)/precuneus], total CTQ scores were positively associated with activation of the PCC/precuneus. Second, exploratory analyses for the rest of the brain (i.e., ROIs masked-out), revealed a positive association between trauma exposure and activation of the dorsomedial prefrontal cortex (dmPFC), and a negative association with activation of the anterior section of the TPJ. These results suggest that childhood trauma exposure may, at least partially, contribute to functional alterations of brain regions essential for effective mental state inference in schizophrenia.