Frontostriatal deficits in unipolar major depression

Cognitive rehabilitation for improving cognitive functions and reducing the severity of depressive symptoms in adult patients with Major Depressive Disorder: a systematic review and meta-analysis of randomized controlled clinical trials

INTRODUCTION

Nearly 40% of patients with Major Depressive Disorder (MDD) have been found to experience cognitive impairment in at least one domain. Cognitive impairment associated with MDD is disproportionately represented in patients that have not fully returned to psychosocial functioning. As awareness regarding cognitive dysfunction in MDD patients grows, so does the interest in developing newer treatments that specifically address these deficits.

METHOD

In the present study, we conduct a systematic review of controlled randomized clinical trials that used cognitive training and remediation interventions for improving cognitive functions and reducing symptom severity in adult patients with MDD. We selected studies published before March 2022 using search databases including PubMed, ScienceDirect, Scopus, and Google scholar. For conducting the meta-analysis, standard differences in means with the random effect model and with a 95% confidence interval of change in outcome measures from baseline to post-intervention between the cognitive rehabilitation and the control groups were calculated.

RESULTS

The database search resulted in identifying 756 studies of interest, which ultimately 15 studies with 410 participants in the cognitive rehabilitation group and 339 participants in the control group were included. The meta-analysis of the data extracted from these studies, shows a moderate and significant effect on the executive function (d = 0.59 (95% CI, 0.25 to 0.93) p-value = 0.001, I² = 15.2%), verbal learning (d = 0.45 (95% CI, 0.12 to 0.78) p-value = 0.007, I² = 0.00%), and working memory (d = 0.41 (95% CI, 0.18 to 0.64) p-value < 0.001, I² = 33%) of MDD patients. Although, there were no significant difference between intervention and control group in attention (d = 0.32 (95% CI, -0.01 to 0.66) p-value = 0.058, I² = 0.00%) or depressive symptoms.

CONCLUSION

This systematic review and meta-analysis indicate that cognitive rehabilitation is an effective intervention for the executive function, verbal learning, and working memory of MDD patients. Due to the importance of these neuropsychological deficits in day-to-day life and the core symptoms of MDD, cognitive rehabilitation should be considered an important part of treating MDD. Further research in this area and concentrated on these particular deficits is warranted.

Unraveling the mystery of white matter in depression: A translational perspective on recent advances

BACKGROUND

Numerous cortical and subcortical structures have been studied extensively concerning alterations of their integrity as well as their neurotransmitters in depression. However, connections between these structures have received considerably less attention.

OBJECTIVE

This systematic review presents results from recent neuroimaging as well as neuropathologic studies conducted on humans and other mammals. It aims to provide evidence for impaired white matter integrity in individuals expressing a depressive phenotype.

METHODS

A systematic database search in accordance with the PRISMA guidelines was conducted to identify imaging and postmortem studies conducted on humans with a diagnosis of major depressive disorder, as well as on rodents and primates subjected to an animal model of depression.

RESULTS

Alterations are especially apparent in frontal gyri, as well as in structures establishing interhemispheric connectivity between frontal regions. Translational neuropathological findings point to alterations in oligodendrocyte density and morphology, as well as to alterations in the expression of genes related to myelin synthesis. An important role of early life adversities in the development of depressive symptoms and white matter alterations across species is thereby revealed. Data indicating that stress can interfere with physiological myelination patterns is presented. Altered myelination is most notably present in regions that are subject to maturation during the developmental stage of exposure to adversities.

CONCLUSION

Translational studies point to replicable alterations in white matter integrity in subjects suffering from depression across multiple species. Impaired white matter integrity is apparent in imaging as well as neuropathological studies. Future studies should focus on determining to what extent influencing white matter integrity is able to improve symptoms of depression in animals as well as humans.

Cytokine and Reward Circuitry Relationships in Treatment-Resistant Depression

BACKGROUND

Depressive disorders are linked to dysfunction in reward-related behaviors and corticostriatal reward circuitry. Low-grade dysregulation of the immune system, e.g., elevations in plasma interleukin 6 (IL-6) and tumor necrosis factor α, have been thought to affect corticostriatal reward circuitry. Little is presently known about the degree to which these relationships generalize to patients with treatment-resistant depression (TRD) and/or childhood trauma history.

METHODS

Resting-state functional connectivity between the ventral striatum (VS) and ventromedial prefrontal cortex (vmPFC) regions and plasma inflammatory marker levels (IL-6, tumor necrosis factor α) were measured in 74 adults with TRD. Regression analyses examined associations of inflammatory markers with VS-vmPFC connectivity and the moderating effects of self-reported childhood trauma on these associations, with exploratory analyses examining trauma subtypes.

RESULTS

IL-6 was negatively associated with VS-vmPFC connectivity (specifically for the left VS). Childhood trauma moderated the relationships between tumor necrosis factor α and VS-vmPFC connectivity (specifically for the right VS) such that greater childhood trauma severity (particularly emotional neglect) was associated with stronger cytokine-connectivity associations.

CONCLUSIONS

This study independently extends previously reported associations between IL-6 and reductions in corticostriatal connectivity to a high-priority clinical population of treatment-seeking patients with TRD and further suggests that childhood trauma moderates specific associations between cytokines and corticostriatal connectivity. These findings suggest that associations between elevated plasma cytokine levels and reduced corticostriatal connectivity are a potential pathophysiological mechanism generalizable to patients with TRD and that such associations may be affected by trauma severity.

Cognitive remediation therapy modulates intrinsic neural activity in patients with major depression

BACKGROUND

Cognitive impairment is a core feature of major depressive disorder (MDD). Cognitive remediation may improve cognition in MDD, yet so far, the underlying neural mechanisms are unclear. This study investigated changes in intrinsic neural activity in MDD after a cognitive remediation trial.

METHODS

In a longitudinal design, 20 patients with MDD and pronounced cognitive deficits and 18 healthy controls (HC) were examined using resting-state functional magnetic resonance imaging. MDD patients received structured cognitive remediation therapy (CRT) over 5 weeks. The whole-brain fractional amplitude of low-frequency fluctuations was computed before the first and after the last training session. Univariate methods were used to address regionally-specific effects, and a multivariate data analysis strategy was employed to investigate functional network strength (FNS).

RESULTS

MDD patients significantly improved in cognitive function after CRT. Baseline comparisons revealed increased right caudate activity and reduced activity in the left frontal cortex, parietal lobule, insula, and precuneus in MDD compared to HC. In patients, reduced FNS was found in a bilateral prefrontal system at baseline (p < 0.05, uncorrected). In MDD, intrinsic neural activity increased in right inferior frontal gyrus after CRT (p < 0.05, small volume corrected). Left inferior parietal lobule, left insula, left precuneus, and right caudate activity showed associations with cognitive improvement (p < 0.05, uncorrected). Prefrontal network strength increased in patients after CRT, but this increase was not associated with improved cognitive performance.

CONCLUSIONS

Our findings support the role of intrinsic neural activity of the prefrontal cortex as a possible mediator of cognitive improvement following CRT in MDD.

Functional Dysconnectivity of Frontal Cortex to Striatum Predicts Ketamine Infusion Response in Treatment-Resistant Depression

BACKGROUND

Frontostriatal disconnectivity plays a crucial role in the pathophysiology of major depressive disorder. However, whether the baseline functional connectivity of the frontostriatal network could predict the treatment outcome of low-dose ketamine infusion remains unknown.

METHODS

In total, 48 patients with treatment-resistant depression were randomly divided into 3 treatment groups (a single-dose 40-minute i.v. infusion) as follows: 0.5 mg/kg ketamine, 0.2 mg/kg ketamine, and saline placebo infusion. Patients were subsequently followed-up for 2 weeks. Resting-state functional magnetic resonance imaging was performed for each patient before infusion administration. In addition, the baseline frontostriatal functional connectivity of patients with treatment-resistant depression was also compared with that of healthy controls.

RESULTS

Compared with the healthy controls, patients with treatment-resistant depression had a decreased functional connectivity in the frontostriatal circuits, especially between the right superior frontal cortex and executive region of the striatum and between the right paracingulate cortex and rostral-motor region of the striatum. The baseline hypoconnectivity of the bilateral superior frontal cortex to the executive region of the striatum was associated with a greater reduction of depression symptoms after a single 0.2-mg/kg ketamine infusion.

CONCLUSION

Reduced connectivity of the superior frontal cortex to the striatum predicted the response to ketamine infusion among patients with treatment-resistant depression.

Cannabis, Decision-Making, and Online Assistance Seeking

BACKGROUND AND OBJECTIVES

Maladaptive decision-making strategies could contribute to cannabis-related problems, as some individuals may neither select safe patterns of cannabis use, nor seek treatment.

METHODS

To explore decision-making styles and their relationship to cannabis-related harm, 153 respondents completed the Cannabis Use Disorders Identification Test-Revised (CUDIT-R), the Melbourne Decision Making Questionnaire (MDMQ), and answered questions about their willingness to seek online: (1) further information or (2) treatment for cannabis-related issues.

RESULTS

Multiple regression considered relationships between problematic cannabis use, decision-making style, and cannabis use within the past month. Subscales of the CUDIT-R revealed that: (1) hazardous use was associated with higher hypervigilance and higher decisional self-esteem; (2) dependence symptoms were associated with lower vigilance and higher procrastination; and (3) harmful use was associated with higher procrastination. People with symptoms of CUD were less likely to seek further help or support online if prone to procrastination or buckpasssing.

DISCUSSION AND CONCLUSIONS

Decisional style influenced cannabis use and symptoms. Those people with cannabis-related problems that did not seek online assistance were defensively avoidant.

SCIENTIFIC SIGNIFICANCE

Procrastination is a feature of problematic cannabis use. Online offers of assistance may be ignored by defensively avoidant CUD clients. (Am J Addict 2019;00:1-7).

A Focus on the Functions of Area 25

Subcallosal area 25 is one of the least understood regions of the anterior cingulate cortex, but activity in this area is emerging as a crucial correlate of mood and affective disorder symptomatology. The cortical and subcortical connectivity of area 25 suggests it may act as an interface between the bioregulatory and emotional states that are aberrant in disorders such as depression. However, evidence for such a role is limited because of uncertainty over the functional homologue of area 25 in rodents, which hinders cross-species translation. This emphasizes the need for causal manipulations in monkeys in which area 25, and the prefrontal and cingulate regions in which it is embedded, resemble those of humans more than rodents. In this review, we consider physiological and behavioral evidence from non-pathological and pathological studies in humans and from manipulations of area 25 in monkeys and its putative homologue, the infralimbic cortex (IL), in rodents. We highlight the similarities between area 25 function in monkeys and IL function in rodents with respect to the regulation of reward-driven responses, but also the apparent inconsistencies in the regulation of threat responses, not only between the rodent and monkey literatures, but also within the rodent literature. Overall, we provide evidence for a causal role of area 25 in both the enhanced negative affect and decreased positive affect that is characteristic of affective disorders, and the cardiovascular and endocrine perturbations that accompany these mood changes. We end with a brief consideration of how future studies should be tailored to best translate these findings into the clinic.

Cannabis, alcohol use, psychological distress, and decision-making style

INTRODUCTION

There have been suggestions of hypofrontality in cannabis users. To understand cannabis-related differences in decisional processes, Janis and Mann's conflict model of decision making was applied to recreational cannabis smokers who varied in their alcohol use and level of psychological distress.

METHOD

An online sample of recreational substance users (114 male, 119 female) completed the Melbourne Decision Making Questionnaire, the Alcohol Use Disorders Identification Test (AUDIT), Kessler's Psychological Distress Scale (K10), and the Severity of Dependence Scale (SDS) for cannabis.

RESULTS

Multivariate analysis of variance examined self-reported decision-making styles as a function of gender, recent cannabis use, risky alcohol consumption, and levels of psychological distress. Psychological distress was associated with lower decisional self-esteem and higher levels of procrastination and buck-passing. There were gender differences associated with cannabis use. Female cannabis users reported higher levels of hypervigilance, while male cannabis users reported lower levels of buck-passing.

CONCLUSIONS

Although there was little indication of an avoidant decisional style in cannabis users, the results suggest that cannabis affects decisional processes, contributing to panic in females and impulsivity in males.

Regional Coherence Changes in Alzheimer's Disease Patients with Depressive Symptoms: A Resting-State Functional MRI Study

Alzheimer's disease (AD) is characterized by progressive cognitive decline along with neuropsychiatric symptoms including depression and psychosis. Depression is a common psychiatric disorder occurring in people across the lifespan. Accumulating evidence indicates that depression may be a prodrome and/or a "risk factor" for AD. However, whether AD and depression share a common pathophysiological pathway is still unclear. The aim of this study was to identify regional alterations in brain function associated with depressive symptoms in mild AD patients. Thirty-two mild AD patients were evaluated using the Neuropsychiatric Inventory and Hamilton Depression Rating Scale, and were divided into two groups: 15 AD patients with depressive symptoms (D-AD) and 17 non-depressed AD (nD-AD) patients. Using the approach of regional homogeneity (ReHo), we characterized resting-state regional brain activity in D-AD and nD-AD patients. Compared with nD-AD patients, D-AD patients showed decreased ReHo in the right precentral gyrus, right superior frontal gyrus, right middle frontal gyrus, and right inferior frontal cortex. Our findings show regional brain activity alterations in D-AD patients. Thus, D-AD pathogenesis may be attributed to abnormal neural activity in multiple brain regions.

Brain Systems Underlying Susceptibility to Helplessness and Depression

There has been a relative lack of research into the neurobiological predispositions that confer vulnerability to depression. This article reviews functional brain mappings from a genetic animal model, the congenitally helpless rat, which is predisposed to develop learned helplessness. Neurometabolic findings from this model are integrated with the neuroscientific literature from other animal models of depression as well as depressed humans. Changes in four major brain systems are suggested to underlie susceptibility to helplessness and possibly depression: (a) an unbalanced prefrontal-cingulate cortical system, (b) a dissociated hypothalamic-pituitary-adrenal axis, (c) a dissociated septal-hippocampal system, and (d) a hypoactive brain reward system, as exemplified by a hypermetabolic habenula-interpeduncular nucleus pathway and a hypometabolic ventral tegmental area-striatum pathway. Functional interconnections and causal relationships among these systems are considered and further experiments are suggested, with theoretical attention to how an abnormality in any one system could affect the others.

Study of a mechanism responsible for potential antidepressant activity of EMD 386088, a 5-HT6 partial agonist in rats

It was shown that 5-HT₆ receptor agonists can exert pharmacological activity due to various modifications in monoamines’ level and metabolism activity in rats’ brain structures. This finding was correlated with antidepressant- or anxiolytic-like properties of these compounds. The study was designed to establish a possible mechanism of the antidepressant-like activity of the partial 5-HT₆ receptor agonist EMD386088 (5-chloro-2-methyl-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-indole hydrochloride) in rats. The concentrations of monoamines (dopamine (DA), noradrenaline (NA), and serotonin (5-HT)) and the rate of their metabolism were measured ex vivo in the brain structures (hippocampus, nucleus accumbens, striatum) using high-performance liquid chromatography (HPLC). The rats were killed after the forced swim test (FST); the collected tissue samples were used to ex vivo experiments. The potency of EMD386088 to blockade dopamine transporter (DAT) was tested in a functional in vitro study. FST was used to assess the involvement of D₁- and D₂-like receptor subfamilies in antidepressant-like properties of EMD386088. Neurochemical data from ex vivo experiments showed that antiimmobility activity of EMD386088 may be connected with the activation of dopaminergic system, while neither noradrenergic nor serotonergic ones are involved in its effect. EMD386088 also possesses a significant affinity for DAT which may be a mechanism in the abovementioned effect. Behavioral data seem to confirm the importance of dopaminergic system activation in antidepressant-like activity of EMD386088, since this effect, observed in the FST, was abolished by the preferential D₁- and D₂-like receptor subfamily antagonists SCH23390 and sulpiride, respectively. Dopaminergic system is involved in antidepressant-like activity of EMD386088.

The effect of imipramine, ketamine, and zinc in the mouse model of depression

Relationship between the chronic and excessive exposure to glucocorticoids and the development of psychiatric disorders, including depression, has been described in the literature. We decided to investigate whether a combination of agents with antidepressant activity (i.e., imipramine, ketamine, and Zn(2+)) may influence/reverse the depressogenic effect of dexamethasone therapy. The antidepressant-like effect was assessed by the forced swim test in adult mice. The inhibitory activity of dexamethasone was dose-dependent: only the highest tested dose of the glucocorticoid (i.e., 64 μg/kg) given as a single injection increased immobility time, whereas 16 μg/kg/day of dexamethasone administered repeatedly (for 14 days) induced a significant alteration in animal behavior. Both the acute or sub-chronic administration of the active doses of imipramine (10 mg/kg), Zn(2+) (30 mg/kg), and ketamine (30 mg/kg), and the combinations of their per se inactive doses reversed the inhibitory activity of dexamethasone (16 μg/kg/day) administered for 14 consecutive days. Whereas a single injection of an inhibitory dose of dexamethasone (64 μg/kg) was not able to abolish the antidepressant effect of imipramine (5 mg/kg), Zn(2+) (10 mg/kg), and imipramine-Zn(2+) combination (2.5 and 5 mg/kg, respectively) given once a day for 14 consecutive days. Our findings indicate that the chronic dexamethasone injection procedure has some potential as an animal model of depression and they further support the theory of interplay between glutamatergic neurotransmission and the chronic or excessive exposition to glucocorticoids.

Emotion-Dependent Functional Connectivity of the Default Mode Network in Adolescent Depression

BACKGROUND

Functional magnetic resonance imaging research suggests that major depressive disorder (MDD) in both adults and adolescents is marked by aberrant connectivity of the default mode network (DMN) during resting state. However, emotional dysregulation is also a key feature of MDD. No studies to date have examined emotion-related DMN pathology in adolescent depression. Comprehensively understanding the dynamics of DMN connectivity across brain states in individuals with depression with short disease histories could provide insight into the etiology of MDD.

METHODS

We collected functional magnetic resonance imaging data during an emotion identification task and during resting state from 26 medication-free adolescents (13-17 years old) with MDD and 37 well-matched healthy control subjects. We examined between-group differences in blood oxygenation level-dependent task responses and emotion-dependent and resting-state functional connectivity of the two primary nodes of the DMN: medial prefrontal cortex and posterior cingulate cortex (PCC). Additionally, we examined between-group differences in DMN functional connectivity and its relationship to depression severity and onset.

RESULTS

Relative to healthy control subjects, unmedicated adolescents with MDD demonstrated reduced medial prefrontal cortex and PCC emotion-related deactivation and greater medial prefrontal cortex and PCC emotion-dependent functional connectivity with precuneus, cingulate gyrus, and striatum/subcallosal cingulate gyrus. The PCC-subcallosal cingulate connectivity remained inflexibly elevated in the subjects with MDD versus healthy control subjects during resting state. Stronger PCC emotion-dependent functional connectivity was associated with greater depression severity and an earlier age of depression onset.

CONCLUSIONS

Adolescent depression is associated with inflexibly elevated DMN connections. Given more recent evidence of DMN maturation throughout adolescence, our findings suggest that early-onset depression adversely affects normal development of functional brain networks.

Altered white matter integrity in individuals with cognitive vulnerability to depression: a tract-based spatial statistics study

The microstructure of white matter in patients with major depressive disorder (MDD) has been demonstrated to be abnormal. However, it remains unclear whether these changes exist prior to the onset of disease. In this study, diffusion tensor imaging was used to evaluate white matter integrity in individuals who exhibited cognitive vulnerability to depression (CVD), MDD, and healthy controls (HC). Compared with the HC, MDD exhibited a lower fractional anisotropy (FA) in ten brain regions: the cerebral peduncle, the anterior and posterior limbs of the internal capsule (ALIC and PLIC), the external capsule, the retrolenticular part of the internal capsule (RLIC), the body and splenium of the corpus callosum, the superior and posterior corona radiata, and the cingulum. Moreover, CVD had significantly lower FA in the ALIC, the PLIC, the external capsule, the RLIC, the cerebral peduncle, and the superior corona radiata than did the HC. However, the white matter integrity was not significantly different between the CVD and MDD. These preliminary results indicate that alterations in the white matter observed in CVD may be a marker of vulnerability to MDD and that these alterations may exist prior to the onset of depression.

Multi-dimensional modulations of α and γ cortical dynamics following mindfulness-based cognitive therapy in Major Depressive Disorder

To illuminate candidate neural working mechanisms of Mindfulness-Based Cognitive Therapy (MBCT) in the treatment of recurrent depressive disorder, parallel to the potential interplays between modulations in electro-cortical dynamics and depressive symptom severity and self-compassionate experience. Linear and nonlinear α and γ EEG oscillatory dynamics were examined concomitant to an affective Go/NoGo paradigm, pre-to-post MBCT or natural wait-list, in 51 recurrent depressive patients. Specific EEG variables investigated were; (1) induced event-related (de-) synchronisation (ERD/ERS), (2) evoked power, and (3) inter-/intra-hemispheric coherence. Secondary clinical measures included depressive severity and experiences of self-compassion. MBCT significantly downregulated α and γ power, reflecting increased cortical excitability. Enhanced α-desynchronisation/ERD was observed for negative material opposed to attenuated α-ERD towards positively valenced stimuli, suggesting activation of neural networks usually hypoactive in depression, related to positive emotion regulation. MBCT-related increase in left-intra-hemispheric α-coherence of the fronto-parietal circuit aligned with these synchronisation dynamics. Ameliorated depressive severity and increased self-compassionate experience pre-to-post MBCT correlated with α-ERD change. The multi-dimensional neural mechanisms of MBCT pertain to task-specific linear and non-linear neural synchronisation and connectivity network dynamics. We propose MBCT-related modulations in differing cortical oscillatory bands have discrete excitatory (enacting positive emotionality) and inhibitory (disengaging from negative material) effects, where mediation in the α and γ bands relates to the former.

Molecular imaging of neuropsychiatric symptoms in Alzheimer's and Parkinson's disease

Neuropsychiatric symptoms (NPS) are very common in neurodegenerative diseases and are a major contributor to disability and caregiver burden. There is accumulating evidence that NPS may be a prodrome and/or a "risk factor" of neurodegenerative diseases. The medications used to treat these symptoms in younger patients are not very effective in patients with neurodegenerative disease and may have serious side effects. An understanding of the neurobiology of NPS is critical for the development of more effective intervention strategies. Targeting these symptoms may also have implications for prevention of cognitive or motor decline. Molecular brain imaging represents a bridge between basic and clinical observations and provides many opportunities for translation from animal models and human post-mortem studies to in vivo human studies. Molecular brain imaging studies in Alzheimer's disease (AD) and Parkinson's disease (PD) are reviewed with a primary focus on positron emission tomography studies of NPS. Future directions for the field of molecular imaging in AD and PD to understand the neurobiology of NPS will be discussed.

Meta-analysis of molecular imaging of serotonin transporters in major depression

The success of serotonin-selective reuptake inhibitors has lent support to the monoamine theory of major depressive disorder (MDD). This issue has been addressed in a number of molecular imaging studies by positron emission tomography or single-photon emission computed tomography of serotonin reuptake sites (5-HTT) in the brain of patients with MDD, with strikingly disparate conclusions. Our meta-analysis of the 18 such studies, totaling 364 MDD patients free from significant comorbidities or medication and 372 control subjects, revealed reductions in midbrain 5-HTT (Hedges' g=-0.49; 95% CI: (-0.84, -0.14)) and amygdala (Hedges' g=-0.50; 95% CI: (-0.78, -0.22)), which no individual study possessed sufficient power to detect. Only small effect sizes were found in other regions with high binding (thalamus: g=-0.24, striatum: g=-0.32, and brainstem g=-0.22), and no difference in the frontal or cingulate cortex. Age emerged as an important moderator of 5-HTT availability in MDD, with more severe reductions in striatal 5-HTT evident with greater age of the study populations (P<0.01). There was a strong relationship between severity of depression and 5-HTT reductions in the amygdala (P=0.01). Thus, molecular imaging findings indeed reveal widespread reductions of ∼10% in 5-HTT availability in MDD, which may predict altered spatial-temporal dynamics of serotonergic neurotransmission.

Altered cerebral perfusion in executive, affective, and motor networks during adolescent depression

OBJECTIVE

Although substantial literature has reported regional cerebral blood flow (rCBF) abnormalities in adults with depression, these studies commonly necessitated the injection of radioisotopes into subjects. The recent development of arterial spin labeling (ASL), however, allows noninvasive measurements of rCBF. Currently, no published ASL studies have examined cerebral perfusion in adolescents with depression. Thus, the aim of the present study was to examine baseline cerebral perfusion in adolescent depression using a newly developed ASL technique: pseudocontinuous arterial spin labeling (PCASL).

METHOD

A total of 25 medication-naive adolescents (13-17 years of age) diagnosed with major depressive disorder (MDD) and 26 well-matched control subjects underwent functional magnetic resonance imaging. Baseline rCBF was measured via a novel PCASL method that optimizes tagging efficiency.

RESULTS

Voxel-based whole brain analyses revealed significant frontal, limbic, paralimbic, and cingulate hypoperfusion in the group with depression (p < .05, corrected). Hyperperfusion was also observed within the subcallosal cingulate, putamen, and fusiform gyrus (p < .05, corrected). Similarly, region-of-interest analyses revealed amygdalar and insular hypoperfusion in the group with depression, as well as hyperperfusion in the putamen and superior insula (p < .05, corrected).

CONCLUSIONS

Adolescents with depression and healthy adolescents appear to differ on rCBF in executive, affective, and motor networks. Dysfunction in these regions may contribute to the cognitive, emotional, and psychomotor symptoms commonly present in adolescent depression. These findings point to possible biomarkers for adolescent depression that could inform early interventions and treatments, and establishes a methodology for using PCASL to noninvasively measure rCBF in clinical and healthy adolescent populations.

Cognitive impairment in euthymic major depressive disorder: a meta-analysis

BACKGROUND

There is evidence to suggest that cognitive deficits might persist beyond the acute stages of illness in major depressive disorder (MDD). However, the findings are somewhat inconsistent across the individual studies conducted to date. Our aim was to conduct a systematic review and meta-analysis of existing studies that have examined cognition in euthymic MDD patients.

METHOD

Following a systematic search across several publication databases, meta-analyses were conducted for 27 empirical studies that compared euthymic adult MDD patients (895 participants) and healthy controls (997 participants) across a range of cognitive domains. The influence of demographic variables and confounding factors, including age of onset and recurrent episodes, was examined.

RESULTS

Compared with healthy controls, euthymic MDD patients were characterized by significantly poorer cognitive functions. However, the magnitude of observed deficits, with the exception of inhibitory control, were generally modest when late-onset cases were excuded. Late-onset cases demonstrated significantly more pronounced deficits in verbal memory, speed of information processing and some executive functions.

CONCLUSIONS

Cognitive deficits, especially poor response inhibition, are likely to be persistent features, at least of some forms, of adult-onset MDD. More studies are necessary to examine cognitive dysfunction in remitted psychotic, melancholic and bipolar spectrum MDD. Cognitive deficits overall appear to be more common among patients with late-onset depression, supporting the theories suggesting that possible vascular and neurodegenerative factors play a role in a substantial number of these patients.

1-Methyl-1,2,3,4-tetrahydroisoquinoline, an endogenous Neuroprotectant and MAO inhibitor with antidepressant-like properties in the rat

Oxidative stress is a major contributing factor in a range of brain pathologies and in the etiology of depression. 1-Methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ) is an endogenous substance which is present in the mammalian brain and exhibits neuroprotective, and monoamine oxidase (MAO)-inhibiting properties. In the present study, in order to investigate the potential role of 1MeTIQ as an antidepressant, we tested antidepressant-like effects of 1MeTIQ in comparison with desipramine (a classic antidepressant) in the forced swimming test (FST), and using HPLC methodology, we measured the concentrations of monoamines (dopamine, noradrenaline, serotonin) and the rate of their metabolism. 1MeTIQ given alone as well as in combination with desipramine produced an antidepressant-like effect and decreased the immobility time in the FST. Neurochemical data have shown that 1MeTIQ like desipramine, activated the noradrenergic system. However, the mechanism of action of 1MeTIQ is broader than the actions of desipramine, and 1MeTIQ inhibits the MAO-dependent oxidation of dopamine and serotonin in all investigated structures. We can conclude that 1MeTIQ exhibits antidepressant-like activity in the FST in the rat. The mechanism of its antidepressant action differs from desipramine and seems to be mostly associated with the inhibition of the catabolism of monoamines and their increased concentrations in the brain. 1MeTIQ seems to be very beneficial from the clinical point of view as a reversible MAO inhibitor with a significant antidepressant effects.

Greater striatal dopamine transporter density may be associated with major depressive episode

BACKGROUND

We examined striatal dopamine transporter (DAT) distribution volume ratio (DVR) values in subjects with unipolar or bipolar major depressive episode (versus non-depressed healthy volunteers) using the selective DAT radioligand [(99m)Tc]TRODAT-1 and single photon emission computed tomography (SPECT). We hypothesized that striatal DVR values would be greater in depressed versus non-depressed subjects, and that greater DVR values may represent a possible clinical biomarker of depression.

METHODS

[(99m)Tc]TRODAT-1 spect images were acquired from 39 depressed and 103 non-depressed drug-free subjects. The primary outcome measure was the DVR value of [(99m)Tc]TRODAT-1 binding for the putamen region and the combined putamen plus caudate region.

RESULTS

DVR values were significantly correlated across all striatal regions within both subject groups (p<0.005). Depressed subjects had significantly greater DVR values (versus non-depressed subjects) in the putamen (p<0.0005) and the combined putamen plus caudate (p<0.0005) regions. There was no difference in DVR values between unipolar (n=24) and bipolar (n=15) depressed subjects, and no difference in DVR values for depressed subjects with or without prior antidepressant exposure. The predictive probability of the putamen or combined putamen plus caudate DVR value to distinguish depressed from non-depressed subjects was significant (p<0.0005).

LIMITATIONS

DAT values could potentially be influenced by age, gender, diagnosis, prior psychotropic dug exposure, illness length, or symptom severity.

CONCLUSION

Results confirm prior observations of greater striatal DAT density in depressed versus non-depressed subjects, and suggest that greater DVR values may possibly represent a potential diagnostic biomarker for distinguish depressed from non-depressed individuals.

Altered white matter integrity of forebrain in treatment-resistant depression: a diffusion tensor imaging study with tract-based spatial statistics

BACKGROUND

The association between alterations of the white matter (WM) integrity in brain regions and mood dysregulation has been reported in major depressive disorder (MDD). However, there has never been a neuroimaging study in patients who have treatment-resistant depression (TRD) and are in a current treatment-resistant state. In the present study, we used diffusion tensor imaging (DTI) with tract-based spatial statistics (TBSS) method to investigate the WM integrity of different brain regions in patients who had TRD and were in a current treatment-resistant state.

METHODS

Twenty-three patients with TRD and Hamilton Rating Scale total score of ≥18 and 19 healthy controls matched with age, gender, and education level to patients were scanned with DTI. Thirty 4 mm thick, no gap, contiguous axial slices were acquired and fractional anisotropy (FA) images were generated for each participant. An automated TBSS approach was used to analyze the data.

RESULTS

Voxel-wise statistics revealed that patients with TRD had lower FA values in the right anterior limb of internal capsule, the body of corpus callosum, and bilateral external capsule compared to healthy subjects. Patients with TRD did not have increased FA values in any brain regions compared to healthy subjects. There was no correlation between the FA values in any brain region and patients' demographics and the severity of illness.

CONCLUSIONS

Our findings suggest the abnormalities of the WM integrity of neuronal tracts connecting cortical and subcortical nuclei and two brain hemispheres may play a key role in the pathogenesis of TRD.

Altered white matter integrity in young adults with first-episode, treatment-naive, and treatment-responsive depression

Abnormalities of the white matter (WM) tracts integrity in brain areas involved in emotional regulation have been postulated in major depressive disorder (MDD). However, there is no diffusion tensor imaging (DTI) study in patients with treatment-responsive MDD at present. DTI scans were performed on 22 patients with treatment-responsive MDD and 19 well-matched healthy subjects. Tract-based spatial statistics (TBSS) approach was employed to analyze the scans. Voxel-wise statistics revealed four brain WM tracts with lower fractional anisotropy (FA) in patients compared to healthy subjects: the bilateral internal capsule, the genu of corpus callosum, the bilateral anterior corona radiata, and the right external capsule. FA values were nowhere higher in patients compared to healthy subjects. Our findings demonstrate that the abnormalities of the WM tracts, major in the projection fibers and corpus callosum, may contribute to the pathogenesis of treatment-responsive MDD.

Cognitive functions and serum levels of brain-derived neurotrophic factor in patients with major depressive disorder

OBJECTIVE

We assessed major cognitive domains in major depressive disorder (MDD) compared to a healthy control group using neurocognitive tests. We hypothesized that lower serum brain-derived neurotrophic factor (BDNF) levels would be associated with poorer neurocognitive performance in patients with major depression and that these associations would be shown in healthy controls as well.

METHOD

Executive functions, sustaining and focusing of attention, memory functions, and verbal fluency were assessed in this study using the Trail-Making Test (TMT), Stroop Color Word Interference Test-TBAG Form (SCWT), Wisconsin Card Sorting Test (WCST), Test of Variables of Attention (TOVA), Auditory Consonant Trigram test (ACTT), Digit Span subtest of the Wechsler Memory Scale (DST), Rey Auditory Verbal Learning Test (RAVLT), and Controlled Oral Word Association Test (COWAT).

RESULTS

The MDD group showed significantly poorer performance than the control group in cognitive functions; they also had lower levels of BDNF than the control group. However, there was no correlation between cognitive performances and BDNF levels except in the TMT, Part B.

CONCLUSIONS

The current understanding of the importance of neurocognitive assessment and related biological markers in depression is improving. Further studies with larger sample sizes evaluating neurocognitive functions with molecular analyses of BDNF levels may reveal a novel marker for predicting and monitoring neurocognitive deficits in depression.

Developmental risk I: depression and the developing brain

This article discusses recent findings on the neurobiology of pediatric depression as well as the interplay between genetic and environmental factors in determining the risk for the disorder. Utilizing data from both animal and human studies, the authors focus on the evolving understanding of the developmental neurobiology of emotional regulation, cognitive function and social behavior as it applies to the risk and clinical course of depression. Treatment implications and directions for future research are also discussed.

Meta-analysis of volumetric abnormalities in cortico-striatal-pallidal-thalamic circuits in major depressive disorder

BACKGROUND

Abnormalities in cortico-striatal-pallidal-thalamic (CSPT) circuits have been implicated in major depressive disorder (MDD). However, the robustness of these findings across studies is unclear, as is the extent to which they are influenced by demographic, clinical and pharmacological factors.

METHOD

With the aim of clarifying these questions, we conducted a meta-analysis to map the volumetric abnormalities that were most robustly identified in CSPT circuits of individuals with MDD. A systematic search identified 41 studies meeting our inclusion criteria.

RESULTS

There were significant volume reductions in prefrontal (especially orbitofrontal) and anterior cingulate cortices, and also in subcortical structures such as the caudate nucleus and putamen, with effect sizes ranging from small to moderate. The subgenual anterior cingulate and orbitofrontal cortices were significantly smaller in antidepressant-free samples compared to medicated patients. Late-life depression (LLD) tended to be associated with smaller volumes in circumscribed frontal and subcortical structures, with the most robust differences being found in thalamic volume.

CONCLUSIONS

Individuals with major depression demonstrate volumetric abnormalities of CSPT circuits. However, these observations may be restricted to certain subgroups, highlighting the clinical heterogeneity of the disorder. On the basis of this meta-analysis, CSPT abnormalities were more prominent in those with LLD whereas antidepressant use seemed to normalize certain cortical volumetric abnormalities.

Frontal regional homogeneity increased and temporal regional homogeneity decreased after remission of first-episode drug-naïve major depressive disorder with panic disorder patients under duloxetine therapy for 6 weeks

OBJECTIVE

We designed this study to investigate the changes of regional homogeneity (ReHo) after a 6-week duloxetine therapy in first-episode drug-naïve major depressive disorder with panic disorder (FEMDDPD) patients.

METHOD

3T magnetic resonance imaging (MRI) scanning and ReHo functional MRI analysis were performed on 15 patients (male: 5; female: 10; age: 35.87±9.59 years old) at baseline and remitted status (sixth week) compared with 15 healthy control subjects (male: 4; female: 11; age: 34.30±9.87 years old) which were scanned twice within 6 weeks. The ReHo was analyzed by the REST toolbox (resting-state functional MRI data analysis toolbox). The ReHos of different time-points were compared by using paired t test function of REST.

RESULTS

ReHo increased in right superior frontal cortex, right medial frontal cortex and decreased in right superior temporal cortex (uncorrected p<0.00005, cluster threshold>20, surface connected theory) after remission of symptoms in these FEMDDPD patients within 6 weeks (improvements of clinician rating and self rating scale scores; post-hoc corrected p<0.001). No significant changes of ReHo were observed in the controls within 6 weeks (uncorrected p<0.1, no cluster threshold setting, surface connected theory). The changes of ReHo value were mildly correlated with improvements of clinical rating scales with age, gender, depression and anxiety severity as covariates.

CONCLUSION

Our study suggested that differential modulations inside the default mode network probably were associated with remission of FEMDDPD symptoms after duloxetine therapy.

Neural correlates of disbalanced motor control in major depression

BACKGROUND

Motor retardation is a common symptom of major depressive disorder (MDD). Despite the existence of various assessment methods, little is known on the pathobiology of motor retardation. We aimed to elucidate aspects of motor control investigating the association of objective motor activity and resting state cerebral blood flow (CBF).

METHODS

Nineteen control subjects and 20 MDD patients were investigated using arterial spin labeling (ASL) at 3T in the morning to quantify resting state CBF. Afterwards wrist actigraphy was recorded for 24h. CBF, group and activity level (AL) were entered into a whole brain general linear model.

RESULTS

MDD patients had reduced AL. Both groups had linear associations of AL and CBF in bilateral rostral prefrontal cortex. Groups differed in four clusters associated with motor control. In controls a positive association was found in the left caudal cingulate zone (CCZ) and an inverse association in the right external globus pallidus (GPe). MDD patients had positive associations in the right orbitofrontal cortex and inverse associations in the left supplemental motor area.

LIMITATIONS

Patients were on antidepressant medication.

CONCLUSIONS

The pattern of associations between CBF and AL suggest disbalanced motor control in MDD. Findings are in line with the hypothesis of dopamine deficits contributing to motor retardation in MDD.

Frontostriatal functional connectivity in major depressive disorder

BACKGROUND

Abnormalities of the striatum and frontal cortex have been reported consistently in studies of neural structure and function in major depressive disorder (MDD). Despite speculation that compromised connectivity between these regions may underlie symptoms of MDD, little work has investigated the integrity of frontostriatal circuits in this disorder.

METHODS

Functional magnetic resonance images were acquired from 21 currently depressed and 19 never-disordered women during wakeful rest. Using four predefined striatal regions-of-interest, seed-to-whole brain correlations were computed and compared between groups.

RESULTS

Compared to controls, depressed participants exhibited attenuated functional connectivity between the ventral striatum and both ventromedial prefrontal cortex and subgenual anterior cingulate cortex. Depressed participants also exhibited stronger connectivity between the dorsal caudate and dorsal prefrontal cortex, which was positively correlated with severity of the disorder.

CONCLUSIONS

Depressed individuals are characterized by aberrant connectivity in frontostriatal circuits that are posited to support affective and cognitive processing. Further research is required to examine more explicitly the link between patterns of disrupted connectivity and specific symptoms of depression, and the extent to which these patterns precede the onset of depression and normalize with recovery from depressive illness.

Internally vs. externally triggered movements in patients with major depression

BACKGROUND

Psychomotor retardation is a prominent clinical feature of major depression. While several studies investigated these deficits, differences between internally and externally triggered response selection and initiation are less well understood. In the current study, we delineate internally vs. externally driven response selection and initiation in depression and their relation to basic psychomotor functioning.

METHODS

20 inpatients diagnosed with a (unipolar) major depression and 20 closely matched healthy controls performed a computerized motor paradigm assessing differences between internally and externally cued movements. Psychomotor performance and basic memory functions were assessed using a neuropsychological test-battery. To examine within group homogeneity a multivariate clustering approach was applied.

RESULTS

Patients featured a global slowing of internally and externally cued response selection compared to controls, as well as impairments in basic psychomotor functioning. Yet, basic motor speed was preserved. Furthermore, patients were more severely impaired when movements involved internal response selection. The data-driven clustering revealed two patient subgroups, which both showed psychomotor disturbances, while only one featured slowing of response selection.

INTERPRETATION

The results suggest a differential rather than a global psychomotor slowing in major depression with specific impairments of visuospatial and attentional processing as cognitive aspects of psychomotor functioning. As found for depression, in Parkinson's disease internally cued movements are more severely affected than externally cued reactions. Both may therefore be caused by dopaminergic deregulation due to frontostriatal deficits. Finally, multivariate clustering of behavioral data may be a promising future approach to identify subtypes of psychomotor or cognitive disturbances in different patient populations.

Depression and anxious apprehension distinguish frontocingulate cortical activity during top-down attentional control

A network consisting of left dorsolateral prefrontal cortex (LDLPFC) and dorsal anterior cingulate cortex (dACC) has been implicated in top-down attentional control. Few studies have systematically investigated how this network is altered in psychopathology, despite evidence that depression and anxiety are associated with attentional control impairments. Functional MRI and dense-array event-related brain potential (ERP) data were collected in separate sessions from 100 participants during a color-word Stroop task. Functional MRI results guided ERP source modeling to characterize the time course of activity in LDLPFC (300-440 ms) and dACC (520-680 ms). At low levels of depression, LDLPFC activity was indirectly related to Stroop interference and only via dACC activity. In contrast, at high levels of depression, dACC did not play an intervening role, and increased LDLPFC activity was directly related to decreased Stroop interference. Specific to high levels of anxious apprehension, higher dACC activity was related to more Stroop interference. Results indicate that depression and anxious apprehension modulate temporally and functionally distinct aspects of the frontocingulate network involved in top-down attention control.

The WAG/Rij strain: a genetic animal model of absence epilepsy with comorbidity of depression [corrected]

A great number of clinical observations show a relationship between epilepsy and depression. Idiopathic generalized epilepsy, including absence epilepsy, has a genetic basis. The review provides evidence that WAG/Rij rats can be regarded as a valid genetic animal model of absence epilepsy with comorbidity of depression. WAG/Rij rats, originally developed as an animal model of human absence epilepsy, share many EEG and behavioral characteristics resembling absence epilepsy in humans, including the similarity of action of various antiepileptic drugs. Behavioral studies indicate that WAG/Rij rats exhibit depression-like symptoms: decreased investigative activity in the open field test, increased immobility in the forced swimming test, and decreased sucrose consumption and preference (anhedonia). In addition, WAG/Rij rats adopt passive strategies in stressful situations, express some cognitive disturbances (reduced long-term memory), helplessness, and submissiveness, inability to make choice and overcome obstacles, which are typical for depressed patients. Elevated anxiety is not a characteristic (specific) feature of WAG/Rij rats; it is a characteristic for only a sub-strain of WAG/Rij rats susceptible to audiogenic seizures. Interestingly, WAG/Rij rats display a hyper-response to amphetamine similar to anhedonic depressed patients. WAG/Rij rats are sensitive only to chronic, but not acute, antidepressant treatments, suggesting that WAG/Rij rats fulfill a criterion of predictive validity for a putative animal model of depression. However, more and different antidepressant drugs still await evaluation. Depression-like behavioral symptoms in WAG/Rij rats are evident at baseline conditions, not exclusively after stress. Experiments with foot-shock stress do not point towards higher stress sensitivity at both behavioral and hormonal levels. However, freezing behavior (coping deficits) and blunted response of 5HT in the frontal cortex to uncontrollable sound stress, increased c-fos expression in the terminal regions of the meso-cortico-limbic brain systems and greater DA response of the mesolimbic system to forced swim stress suggest that WAG/Rij rats are vulnerable to some, but not to all types of stressors. We propose that genetic absence epileptic WAG/Rij rats have behavioral depression-like symptoms, are vulnerable to stress and might represent a model of chronic low-grade depression (dysthymia). Both 5HT and DAergic abnormalities detected in the brain of WAG/Rij rats are involved in modulation of vulnerability to stress and provocation of behavioral depression-like symptoms. The same neurotransmitter systems modulate SWDs as well. Recent studies suggest that the occurrence and repetition of absence seizures are a precipitant of depression-like behavior. Whether the neurochemical changes are primary to depression-like behavioral alterations remains to be determined. In conclusion, the WAG/Rij rats can be considered as a genetic animal model for absence epilepsy with comorbidity of dysthymia. This model can be used to investigate etiology, pathogenic mechanisms and treatment of a psychiatric comorbidity, such as depression in absence epilepsy, to reveal putative genes contributing to comorbid depressive disorder, and to screen novel psychotropic drugs with a selective and/or complex (dual) action on both pathologies.

The prefrontal-limbic network in depression: Modulation by hypothalamus, basal ganglia and midbrain

The anterior cingulate cortex, amygdala and hippocampus form part of an interconnected prefrontal neocortical and limbic archicortical network that is dysregulated in major depressive disorders (MDD). Modulation of this prefrontal-limbic network (PLN) is principally through the hypothalamus, basal ganglia and midbrain. Here the likely mechanisms by which these modulations are affected are described and the implications of their failure for depression associated with suicidal diathesis, late-life and psychoses discussed.

Cross-sectional and longitudinal assessment of structural brain alterations in melancholic depression

BACKGROUND

Whole-brain imaging approaches may contribute to the characterization of neuroanatomic alterations in major depression, especially in clinically homogenous patient groups such as those with melancholic features. We assessed brain anatomic alterations, both cross-sectionally and longitudinally, in patients with melancholic depression using a whole-brain voxel-wise approach.

METHODS

Whole-brain magnetic resonance images were collected from a relatively aged sample of 70 consecutively recruited major depressive disorder inpatients with melancholic features and from a group of 40 healthy control subjects. All patients were clinically followed for at least 2 years, and a subset of 30 depressive patients and 20 control subjects were rescanned after a 7-year period. Imaging data were analyzed with voxel- and tensor-based morphometry techniques.

RESULTS

Melancholic patients showed gray matter reductions in the left insula and white matter increases in the upper brainstem tegmentum. Male patients showed gray matter decreases in the right thalamus, and periventricular white matter reductions were specifically observed in older patients. Volume decreases in the left insula, hippocampus, and lateral parietal cortex predicted a slower recovery after treatment initiation. In longitudinal assessment, white matter of the upper brainstem tegmentum showed a different temporal evolution between groups. Additionally, bilateral gray matter reductions in the insulae were associated with the number of relapses during follow-up.

CONCLUSIONS

Structural alterations were identified in regions potentially related to relevant aspects of melancholia pathophysiology. Longitudinal analyses indicated region-specific interactions of baseline alterations with age as well as a significant association of clinical severity with focal changes occurring over time.

A morphometric examination of neuronal and glial cell pathology in the orbitofrontal cortex in late-life depression

BACKGROUND

The orbitofrontal cortex has been implicated as a key component in depression by several imaging studies. This study aims to examine morphometrically glial cell and neuronal density and neuronal volume in the orbitofrontal cortex of late-life major depression patients.

METHODS

Post mortem tissue from 13 patients with major depression and 11 matched controls was obtained and analyzed using the optical disector and nucleator methods.

RESULTS

No changes were found in glial cell, pyramidal or non-pyramidal neuron density, or in non-pyramidal and pyramidal neuron volume in the orbitofrontal cortex.

CONCLUSIONS

Based on previous findings, this study suggests variability in morphological changes within the orbitofrontal cortex, as well as the prefrontal cortex as a whole.

White matter changes in healthy adolescents at familial risk for unipolar depression: a diffusion tensor imaging study

Alterations in white matter integrity of several cortical and subcortical circuits have been reported in relation to unipolar major depressive disorder. It is not clear whether these white matter changes precede the onset of illness. In all, 13 adolescent volunteers with no personal or family history of a psychiatric disorder (controls) and 18 adolescent volunteers with no personal history of a psychiatric illness including depression, but who were at high risk for developing unipolar depression by virtue of parental depression (high-risk youth), underwent diffusion tensor imaging studies. An automated tract-based spatial statistics method, a whole-brain voxel-by-voxel analysis, was used to analyze the scans. Population average diffusion parameter values were also calculated for each tract. Adolescents at high risk for unipolar depression had lower fractional anisotropy (FA) values in the left cingulum, splenium of the corpus callosum, superior longitudinal fasciculi, uncinate, and inferior fronto-occipital fasciculi than did controls. Altered white matter integrity in healthy adolescents at familial risk for unipolar depression suggests that it might serve as a vulnerability marker for the illness.

Infant brain development and vulnerability to later internalizing difficulties: the Generation R study

OBJECTIVE

Although clinical studies have demonstrated smaller subcortical volumes in structures such as the amygdala, hippocampus, caudate nucleus, and thalamus in adults and adolescents with depressive disorders and anxiety, no study has assessed such structures in babies, long before the development of the disorders. This study examined whether the size of the "gangliothalamic ovoid" (encompassing the basal ganglia and thalamus) assessed during infancy is associated with increased internalizing problems in early childhood.

METHOD

Cranial ultrasounds were used to assess gangliothalamic ovoid diameter and ventricular volume at 6 weeks of postnatal age; moreover, head circumference was measured. Outcome data included ratings of internalizing and externalizing problems using the Child Behavior Checklist (reported by mothers and fathers) at 18 and/or 36 months. Analyses were based on a total of 651 children.

RESULTS

Smaller gangliothalamic diameter was associated with higher Child Behavior Checklist Internalizing scores at ages 18 and 36 months. Results remained significant after correcting for head circumference and were evident for the DSM-oriented subscales of anxiety problems and affective problems. Total ventricular volume was not consistently associated with Internalizing scores.

CONCLUSIONS

Findings associating infant brain measurements with Child Behavior Checklist mother and father reports at two time points are consistent with previous cross-sectional reports of smaller subcortical volumes in depression. Results were not simply reflective of overall brain development, because the pattern held after adjustment for head circumference. This is the first study to point toward a biological vulnerability evident in infancy, involved in the development of internalizing problems in childhood.

Major Depressive Disorder in recovery and neuropsychological functioning: effects of selective serotonin reuptake inhibitor and dual inhibitor depression treatments on residual cognitive deficits in patients with Major Depressive Disorder in recovery

INTRODUCTION

Cognitive disturbances in Major Depressive Disorder (MDD) could persist beyond the symptomatic phase of the illness. However, the works addressing this topic did not usually account for the possible impact of medication on the cognitive functions of depressed patients. The present study aims to investigate whether MDD patients in remission treated with selective serotonin reuptake inhibitors (SSRI) or dual serotonergic-noradrenergic reuptake inhibitors (SNRI) show cognitive deficits, to study whether the same patients suffer neuropsychological disturbances when they are unmedicated and in recovery phase, and if the previous pharmacological treatment used to achieve the remission of MDD clinical symptoms had any effect in the profile of these patients' cognitive performance in the recovery phase.

METHODS

Thirty-six subjects with MDD treated with escitalopram and 37 depressed patients with duloxetine were compared both in remission phase and 24 weeks later, when they were unmedicated and in recovery phase. They were also compared, in both moments, to 37 healthy subjects.

RESULTS

The control subjects showed a broader better cognitive performance than MDD patients in both measurement moments, but several cognitive functions improved over time. Also, the patients treated with SNRI performed better in memory tests than the SNRI-treated patients in remission phase, and in recovery phase.

LIMITATIONS

Our sample size is somewhat small, and we followed our patients only for 6months after treatment.

CONCLUSIONS

Cognitive functions improve over time in patients with MDD beyond the remission phase, and the antidepressant treatment class used in acute depressive phase could influence his/her memory improvement.

Fibromyalgia and related conditions: electromyogram profile during isometric muscle contraction

OBJECTIVES

To evaluate electromyogram (EMG) profiles in patients with three related conditions: fibromyalgia, chronic fatigue syndrome, and depression.

METHODS

We studied 44 healthy volunteers, 22 patients with fibromyalgia, 11 patients with chronic fatigue syndrome, and 10 patients admitted for depression. The trapezius electromyogram was recorded during maximally sustained, bilateral, 90 degrees abduction of the shoulders. EMG signal frequency and amplitude were measured throughout the test.

RESULTS

In the fibromyalgia group, isometric contraction duration was significantly shorter than in the other two patient groups (P<0.001) and the EMG frequency and amplitude pattern indicated premature discontinuation of the muscle contraction. Findings in the chronic fatigue patients were similar to those in the healthy controls. The patients with depression had a distinctive EMG profile characterized by excessive initial motor-unit recruitment with a shift in the frequency spectrum.

CONCLUSIONS

Fibromyalgia was associated with a specific EMG pattern indicating premature discontinuation of the muscle contraction. Therefore, maximal voluntary muscle contraction tests may be of limited value for assessing function in fibromyalgia patients. Chronic fatigue syndrome patients had similar EMG findings to those in the healthy controls. The EMG alterations in the patients with depression were consistent with manifestations of psychomotor retardation.

Brain volume abnormalities in major depressive disorder: a meta-analysis of magnetic resonance imaging studies

OBJECTIVE

So far, there have been no attempts to integrate the growing number of all brain volumetric magnetic resonance imaging studies in depression. In this comprehensive meta-analysis the magnitude and extent of brain volume differences between 2,418 patients with major depressive disorder and 1,974 healthy individuals from 64 studies was determined.

METHODS

A systematic research was conducted for volumetric magnetic resonance imaging studies of patients with major depressive disorder in relation to healthy control subjects. Studies had to report sufficient data for computation of effect sizes. For each study, the Cohen's d was calculated. All analyses were performed using the random effects model. Additionally, meta-regression analyses were done to explore the effects of potential sources of heterogeneity.

RESULTS

Patients showed large volume reductions in frontal regions, especially in the anterior cingulate and orbitofrontal cortex with smaller reductions in the prefrontal cortex. The hippocampus, the putamen and caudate nucleus showed moderate volume reductions.

CONCLUSIONS

This is the first comprehensive meta-analysis in major depressive disorder demonstrating structural brain abnormalities, particularly in those brain areas that are involved in emotion processing and stress-regulation.

ROBERTE. Research advances in geriatric depression

Technical advances have facilitated the exploration of factors related to geriatric depression and have helped generate novel biological and psychosocial treatment approaches. This review summarizes the main advancements in epidemiology, clinical presentation and course, genetics, and other areas of biological research. Treatment interventions outlined in this paper include electroconvulsive therapy, repetitive transcranial magnetic stimulation, magnetic seizure therapy, vagus nerve stimulation, deep brain stimulatn, depression prophylaxis, multidisciplinary approaches to depression treatment, and psychotherapy. Forms of psychotherapy for geriatric depression summarized include interpersonal psychotherapy, supportive psychotherapy, cognitive-behavioral therapy, problem-solving therapy, and ecosystem-focused therapy. Neuroimaging techniques based on magnetic resonance imaging are discussed briefly, including volumetric brain studies, diffusion tensor imaging, fractional anisotropy, fiber tractography, magnetization transfer imaging, and blood-oxygenation-level-dependent functional magnetic resonance imaging. Finally, treatment effectiveness is addressed in a discussion of new models to improve access to and quality of care offered in the community.

Depressive-like behavior in mice recently recovered from motor disorders after 3-nitropropionic acid intoxication

OBJECTIVE

Striatum may be involved in depressive disorders according to the neuroimaging analysis and clinical data. However, no animal model at present supported the possible role of striatum in the pathogenesis of depression. In the present study, we have investigated the depressive-like behavior in mice recently intoxicated with 3-nitropropionic acid (3-NP), a widely known toxin that selectively damages the striatum in the brain.

METHODS

Mouse model was made with subacute systemic 3-NP treatment, and the depressive-like behavior was measured using the duration of immobility during forced swimming test (FST).

RESULTS

When the mice at day 15 post-intoxication just totally recovered from motor deficits, the duration of immobility in FST was significantly longer than that in controls. The depressive-like behavior was not due to the fatigue or general sickness following 3-NP intoxication and could be reversed by the antidepressant, desipramine hydrochloride. In two successive FST in 24 h interval, the depressive-like behavior could be observed again in subsequent FST (at day 16 post-intoxication), and the mice presented a normal "learned helplessness".

CONCLUSION

A novel depression animal model could be established in mice during the initial period of recovery from 3-NP intoxication. The depression-like behavior might occur independently without involvement of cognitive defects, and the striatal lesions may underlie the depression-like behavior attributable to 3-NP intoxication.