Regional brain volume in depression and anxiety disorders

Analysis of the presence or absence of atrophy of the subgenual and subcallosal cingulate cortices using voxel-based morphometry on MRI is useful to select prescriptions for patients with depressive symptoms

Objective

We objectively evaluated the presence or absence of atrophy of the subgenual anterior cingulate cortex (sgACC) and the subcallosal anterior cingulate cortex (scACC), using new voxel-based morphometry (VBM) software employing Statistical Parametric Mapping software v8 and diffeomorphic anatomic registration through an exponentiated lie algebra. We prepared a database covering young-mature adulthood and investigated the clinical usefulness of the evaluation.

Subjects and methods

One hundred seven patients with major depressive disorder (MDD), 74 patients with bipolar disorder (BD), and 240 healthy control subjects underwent 1.5T magnetic resonance imaging scanning. Using new VBM software and databases covering young-mature adults and the elderly, target volumes of interest were set in the sgACC and scACC, four indicators (severity, extent, ratio, and whole-brain extent) were determined, and the presence or absence of atrophy of the sgACC and scACC was evaluated on the basis of the indicators. In addition, the relationships between the presence or absence of atrophy of the sgACC and scACC and performance of diagnosing MDD and BD and therapeutic drugs were investigated.

Results

It was clarified that the disease is likely to be MDD when atrophy is detected in the sgACC, and likely to be BD when no atrophy is detected in the sgACC but is detected in the scACC. Regarding the relationship with therapeutic drugs, it was clarified that, when atrophy is detected in both the sgACC and the scACC, concomitant administration of mood stabilizers and atypical antipsychotics acting as dopamine-system stabilizers is necessary in many cases.

Conclusion

VBM on magnetic resonance imaging enabled automatic analysis of atrophy in the sgACC and scACC, and findings obtained by this procedure are useful not only for differentiation of MDD and BD patients but also for selection of prescriptions.

Gray matter volume abnormalities in depressive patients with and without anxiety disorders

Comorbidity with anxiety disorder is a relatively common occurrence in major depressive disorder. However, the unique and shared neuroanatomical characteristics of depression and anxiety disorders have not been fully identified. The aim of this study was to identify gray matter abnormalities and their clinical correlates in depressive patients with and without anxiety disorders. We applied voxel-based morphometry and region-of-interest analyses of gray matter volume (GMV) in normal controls (NC group, n = 28), depressive patients without anxiety disorder (DP group, n = 18), and depressive patients with anxiety disorder (DPA group, n = 20). The correlations between regional GMV and clinical data were analyzed. The DP group showed decreased GMV in the left insula (INS) and left triangular part of the inferior frontal gyrus when compared to the NC group. The DPA group showed greater GMV in the midbrain, medial prefrontal cortex, and primary motor/somatosensory cortex when compared to the NC group. Moreover, the DPA group showed greater GMV than the DP group in the frontal, INS, and temporal lobes. Most gray matter anomalies were significantly correlated with depression severity or anxiety symptoms. These correlations were categorized into 4 trend models, of which 3 trend models (ie, Models I, II, and IV) revealed the direction of the correlation between regional GMV and depression severity to be the opposite of that between regional GMV and anxiety symptoms. Importantly, the left INS showed a trend Model I, which might be critically important for distinguishing depressive patients with and without anxiety disorder. Our findings of gray matter abnormalities, their correlations with clinical data, and the trend models showing opposite direction may reflect disorder-specific symptom characteristics and help explain the neurobiological differences between depression and anxiety disorder.

Dissociation of glutamate and cortical thickness is restricted to regions subserving trait but not state markers in major depressive disorder

BACKGROUND

The anterior cingulate cortex (ACC) plays an important role in the neuropathology of major depressive disorder (MDD). So far, the effect of local cortical alteration on metabolites in multiple subdivisions of ACC has not been studied. We aimed to investigate structural and biochemical changes and their relationship in the pregenual ACC (pgACC), dorsal ACC (dACC) in MDD.

METHODS

We obtained magnetic resonance spectroscopy (MRS) in two investigated regions for 24 depressed patients and matched controls. In each region, cortical thickness (CTh) was calculated within a template mask based on its MRS voxel. We investigated neurotransmitter concentrations of Glx, N-acetyl aspartate (NAA), and myo-inositol (m-Ins) in two investigated regions, as well as their relationships with CTh in depressed individuals and healthy controls.

RESULTS

Patients showed significantly lower cortical thickness in dACC compared to controls. Glx in dACC significantly correlated with CTh in healthy controls but not MDD patients, while NAA and CTh in dACC significantly correlated in both groups. A marginal decrease of Glx in pgACC was found in the subgroup of more severely depressive patients, compared to the mildly depressed patients.

LIMITATIONS

Modest sample size and lack of episodes of depression may limit the generalizability of our findings.

CONCLUSION

Our results indicate an abolished CTh-MRS relation in dACC-associated with structural decline-but not in pgACC, where acute MRS alterations prevailed. Our study provides the first evidence of a neurochemical basis explaining some of the inter-individual variability in CTh in MDD.

Influence of age of onset on limbic and paralimbic structures in depression

AIM

Major depressive disorder (MDD) onset during childhood/adolescence is associated with a greater illness burden and distinct clinical profile. However, limited research exists on the effect of age of MDD onset on volumetric abnormalities in para/limbic structures during adulthood.

METHODS

Subgenual anterior cingulate cortex (sgACC), hippocampus and caudate nucleus volumes were measured by manual tracing in depressed individuals (n = 45) and healthy controls (HC; n = 19). Volumetric comparisons were carried out between HC and MDD patients divided into those with pediatric (≤ 18 years; n = 17) and adult onset (≥ 19 years; n = 28).

RESULTS

The adult MDD-onset group had smaller sgACC volumes than the pediatric-onset and HC groups (age, sex controlled). No differences in caudate and hippocampus volumes existed. sgACC and hippocampal volumes were inversely correlated with depression severity.

CONCLUSIONS

Surprisingly, pediatric MDD-onset was not associated with more pronounced sgACC, hippocampus and caudate volume reductions. Nevertheless, age of illness onset appears to be a meaningful dimension of study in efforts to understand the neurobiological heterogeneity of MDD.

Decreased inter-hemispheric connectivity in anterior sub-network of default mode network and cerebellum: significant findings in major depressive disorder

The issue of inter-hemispheric connectivity is an emerging new area in understanding the pathophysiology of depression. This study was designed to analyse the pattern of inter-hemispheric connectivity in patients with major depressive disorder (MDD). The resting-state functional magnetic resonance imaging (RFMRI) was acquired in all enrolled patients and controls. We used a method of voxel-mirrored homotopic connectivity (VMHC) to estimate the significant differences in inter-hemispheric connectivity between 44 patients with first-episode medication-naïve MDD and 27 normal controls. The patients and controls were matched for age and gender. The patients with first-episode medication-naïve MDD showed lower VMHC than normal controls in bilateral medial frontal cortex, anterior cingulate and cerebellar posterior lobe. The strength of inter-hemispheric connectivity VMHC value was negatively correlated with clinical severity of MDD. From the results, we suggested that decreased inter-hemispheric connectivity in the anterior sub-network of the default mode network and the cerebellar posterior lobe might represent an emerging finding in the pathophysiology for MDD.

Cerebral metabolism in major depressive disorder: a voxel-based meta-analysis of positron emission tomography studies

BACKGROUND

Major depressive disorder (MDD) is a common mental illness with high lifetime prevalence close to 20%. Positron emission tomography (PET) studies have reported decreased prefrontal, insular and limbic cerebral glucose metabolism in depressed patients compared with healthy controls. However, the literature has not always been consistent. To evaluate current evidence from PET studies, we conducted a voxel-based meta-analysis of cerebral metabolism in MDD.

METHOD

Data were collected from databases including PubMed and Web of Science, with the last report up to April 2013. Voxel-based meta-analyses were performed using the revised activation likelihood estimation (ALE) software.

RESULTS

Ten whole-brain-based FDG-PET studies in MDD were included in the meta-analysis, comprising 188 MDD patients and 169 healthy controls. ALE analyses showed the brain metabolism in bilateral insula, left lentiform nucleus putamen and extra-nuclear, right caudate and cingulate gyrus were significantly decreased. However, the brain activity in right thalamus pulvinar and declive of posterior lobe, left culmen of vermis in anterior lobe were significantly increased in MDD patients.

CONCLUSION

Our meta-analysis demonstrates the specific brain regions where possible dysfunctions are more consistently reported in MDD patients. Altered metabolism in insula, limbic system, basal ganglia, thalamus, and cerebellum and thus these regions are likely to play a key role in the pathophysiology of depression.

Altered gray matter volume and school age anxiety in children born late preterm

OBJECTIVES

To determine if late preterm (LP) children differ from full term (FT) children in volumes of the cortex, hippocampus, corpus callosum, or amygdala and whether these differences are associated with anxiety symptoms at school-age.

STUDY DESIGN

LP children born between 34 and 36 weeks gestation and FT children born between 39 and 41 weeks gestation from a larger longitudinal cohort had magnetic resonance imaging scans at school-age. Brain volumes, cortical surface area, and thickness measures were obtained. Anxiety symptoms were assessed using a structured diagnostic interview annually beginning at preschool-age and following the magnetic resonance imaging.

RESULTS

LP children (n = 21) had a smaller percentage of total, right parietal, and right temporal lobe gray matter volume than FT children (n = 87). There were no differences in hippocampal, callosal, or amygdala volumes or cortical thickness. LP children also had a relative decrease in right parietal lobe cortical surface area. LP children had greater anxiety symptoms over all assessments. The relationship between late prematurity and school-age anxiety symptoms was mediated by the relative decrease in right temporal lobe volume.

CONCLUSIONS

LP children, comprising 70% of preterm children, are also at increased risk for altered brain development particularly in the right temporal and parietal cortices. Alterations in the right temporal lobe cortical volume may underlie the increased rate of anxiety symptoms among these LP children. These findings suggest that LP delivery may disrupt temporal and parietal cortical development that persists until school-age with the right temporal lobe conferring risk for elevated anxiety symptoms.

Ventromedial prefrontal cortex regulates depressive-like behavior and rapid eye movement sleep in the rat

Major depressive disorder (MDD) is a debilitating disease with symptoms like persistent depressed mood and sleep disturbances. The prefrontal cortex (PFC) has been implicated as an important structure in the neural circuitry of MDD, with pronounced abnormalities in blood flow and metabolic activity in PFC subregions, including the subgenual cingulate cortex (sgACC, or Brodmann area 25). In addition, deep brain stimulation in the sgACC has recently been shown to alleviate treatment-resistant depression. Depressed patients also show characteristic changes in sleep: insomnia, increased rapid-eye-movement (REM) sleep and shortened REM sleep latency. We hypothesized that sleep changes and depressive behavior may be a consequence of the abnormal PFC activity in MDD. The rat ventromedial PFC (vmPFC, prelimbic and infralimbic cortices) is considered to be the homolog of the human sgACC, so we examined the effect of excitotic lesions in the vmPFC on sleep-wake and depressive behavior. We also made lesions in the adjacent dorsal region (dmPFC) to compare the effect of this similar but distinct mPFC region. We found that both dmPFC and vmPFC lesions led to increased REM sleep, but only vmPFC-lesioned animals displayed increased sleep fragmentation, shortened REM latency and increased immobility in the forced swim test. Anatomic tracing suggests that the mPFC projects to the pontine REM-off neurons that interact with REM-on neurons in the dorsal pons. These results support our hypothesis that neuronal loss in the rat vmPFC resembles several characteristics of MDD and may be a critical area for modulating both mood and sleep.

Glutamate level in anterior cingulate predicts anxiety in healthy humans: a magnetic resonance spectroscopy study

Anxiety, a personality dimension in healthy humans, has been found to be associated with many functional consequences such as increased distractibility and attentional bias in favour of threat-related information, along with morphological and microstructural changes in the brain. The associated metabolic/neurochemical alterations are sparsely studied. In the present magnetic resonance spectroscopy (MRS) study, we investigated the possible relationship between regional brain chemistry within anterior cingulate cortex (4-cm(3) voxel) and hippocampus (2.5-cm(3) voxel) and anxiety (measured by State-Trait Anxiety Inventory) in our subject group. In the anterior cingulate cortex, multivariate analysis of covariance showed an increase in myo-inositol and combined glutamate and glutamine levels in the high anxiety subject group as compared with the low anxiety group. In the partial correlation analysis between neurochemicals and anxiety, glutamate and combined glutamate and glutamine also showed a predictive value for anxiety. On analysing the trait anxiety sub-score separately, we found glutamate, inositol and combined glutamate and glutamine levels to be increased in the high trait anxiety group as compared with the low trait anxiety group. All three resonances also had a predictive value for trait anxiety. In the hippocampus, none of the neurochemicals showed significant difference between high and low anxiety groups. The study provides a first account of alterations in anterior cingulate cortex neurochemistry in relation to anxiety in healthy subjects. The study thus contributes to the limited literature available on altered metabolism and neural mechanisms underlying sub-clinical anxiety.

Insular and hippocampal gray matter volume reductions in patients with major depressive disorder

Background

Major depressive disorder is a serious psychiatric illness with a highly variable and heterogeneous clinical course. Due to the lack of consistent data from previous studies, the study of morphometric changes in major depressive disorder is still a major point of research requiring additional studies. The aim of the study presented here was to characterize and quantify regional gray matter abnormalities in a large sample of clinically well-characterized patients with major depressive disorder.

Methods

For this study one-hundred thirty two patients with major depressive disorder and 132 age- and gender-matched healthy control participants were included, 35 with their first episode and 97 with recurrent depression. To analyse gray matter abnormalities, voxel-based morphometry (VBM8) was employed on T1 weighted MRI data. We performed whole-brain analyses as well as a region-of-interest approach on the hippocampal formation, anterior cingulate cortex and amygdala, correlating the number of depressive episodes.

Results

Compared to healthy control persons, patients showed a strong gray-matter reduction in the right anterior insula. In addition, region-of-interest analyses revealed significant gray-matter reductions in the hippocampal formation. The observed alterations were more severe in patients with recurrent depressive episodes than in patients with a first episode. The number of depressive episodes was negatively correlated with gray-matter volume in the right hippocampus and right amygdala.

Conclusions

The anterior insula gray matter structure appears to be strongly affected in major depressive disorder and might play an important role in the neurobiology of depression. The hippocampal and amygdala volume loss cumulating with the number of episodes might be explained either by repeated neurotoxic stress or alternatively by higher relapse rates in patients showing hippocampal atrophy.

Local cortical thinning links to resting-state disconnectivity in major depressive disorder

BACKGROUND

Local structural and metabolic as well as inter-regional connectivity abnormalities have been implicated in the neuropathology of major depressive disorder (MDD). How local tissue properties affect intrinsic functional connectivity is, however, unclear. Using a cross-sectional, multi-modal imaging approach, we investigated the relationship between local cortical tissue abnormalities and intrinsic resting-state functional connectivity (RSFC) in MDD.

METHOD

A total of 20 MDD in-patients and 20 healthy controls underwent magnetic resonance imaging at 3 T for structural and functional imaging. Whole-brain cortical thickness was calculated and compared between groups. Regions with reduced cortical thickness defined seeds for subsequent whole-brain RSFC analyses. Contributions of structural tissue abnormalities on inter-regional RSFC were explicitly investigated.

RESULTS

Lower cortical thickness was observed in MDD in the right dorsomedial prefrontal cortex (PFC), superior temporal gyrus/temporal pole, middle-posterior cingulate cortex, and dorsolateral PFC. No differences in local fractional amplitude of low-frequency fluctuations were observed. Lower thickness in patients' dorsomedial PFC further directly and selectively affected its RSFC with the precuneus, which was unaffected by symptom severity. No effects of cortical thickness in other regions showing abnormal thickness were observed to influence functional connectivity.

CONCLUSIONS

Abnormal cortical thickness in the dorsomedial PFC in MDD patients was observed to selectively and directly affect its intrinsic connectivity with the precuneus in MDD patients independent of depression severity, thereby marking a potential vulnerability for maladaptive mood regulation. Future studies should include an unmedicated sample and replicate findings using independent component analysis to test for morphometric effects on network integrity.

Functional t1ρ imaging in panic disorder

BACKGROUND

Abnormal brain pH has been suggested to play a critical role in panic disorder. To investigate this possibility, we employed a pH-sensitive magnetic resonance (MR) imaging strategy (T1 relaxation in the rotating frame [T1ρ]) and conventional blood oxygen level-dependent (BOLD) imaging.

METHODS

Thirteen panic disorder participants and 13 matched control subjects were enrolled in the study. T1ρ and BOLD were used to study the functional response to a visual flashing checkerboard and their relationship to panic symptoms assessed using the Beck Anxiety Inventory.

RESULTS

In response to visual stimulation, T1ρ imaging revealed a significantly greater increase in the visual cortex of panic disorder participants. T1ρ also detected a stimulus-evoked decrease in the anterior cingulate cortex. Blood oxygen level-dependent imaging detected no functional differences between groups. The correspondence between panic symptoms and functional T1ρ response identified significant relationships within the left inferior parietal lobe, left middle temporal gyrus, and right insula. No relationships were found between panic symptoms and the BOLD signal.

CONCLUSIONS

The data suggest greater activity-evoked T1ρ changes in the visual cortex and anterior cingulate cortex of panic disorder participants. These observations are consistent with a pH dysregulation in panic disorder. In addition, our data suggest that T1ρ imaging may provide information about panic disorder that is distinct from conventional BOLD imaging and may reflect abnormalities in pH and/or brain metabolism.

Multimodal voxel-based meta-analysis of white matter abnormalities in obsessive-compulsive disorder

White matter (WM) abnormalities have long been suspected in obsessive-compulsive disorder (OCD) but the available evidence has been inconsistent. We conducted the first multimodal meta-analysis of WM volume (WMV) and fractional anisotropy (FA) studies in OCD. All voxel-wise studies comparing WMV or FA between patients with OCD and healthy controls in the PubMed, ScienceDirect, Google Scholar, Web of Knowledge and Scopus databases were retrieved. Manual searches were also conducted and authors were contacted soliciting additional data. Thirty-four data sets were identified, of which 22 met inclusion criteria (five of them unpublished; comprising 537 adult and pediatric patients with OCD and 575 matched healthy controls). Whenever possible, raw statistical parametric maps were also obtained from the authors. Peak and raw WMV and FA data were combined using novel multimodal meta-analytic methods implemented in effect-size signed differential mapping. Patients with OCD showed widespread WM abnormalities, but findings were particularly robust in the anterior midline tracts (crossing between anterior parts of cingulum bundle and body of corpus callosum), which showed both increased WMV and decreased FA, possibly suggesting an increase of fiber crossing in these regions. This finding was also observed when the analysis was limited to adult participants, and especially pronounced in samples with a higher proportion of medicated patients. Therefore, patients with OCD may have widespread WM abnormalities, particularly evident in anterior midline tracts, although these changes might be, at least in part, attributable to the effects of therapeutic drugs.

Regional differences in acute corticosterone-induced dendritic remodeling in the rat brain and their behavioral consequences

BACKGROUND

Glucocorticoid released by stressful stimuli elicits various stress responses. Acute treatment with a single dose of corticosterone (CORT; predominant glucocorticoid of rats) alone has previously been shown to trigger anxiety behavior and robust dendritic hypertrophy of neurons in the basolateral amygdala (BLA). Neurons in the medial prefrontal cortex (mPFC) are also known to be highly sensitive to stress and regulate anxiety-like behaviors. Nevertheless, we know less about acute CORT-induced structural changes of other brain regions and their behavioral outcomes. In addition, the temporal profile of acute CORT effects remains to be examined. The current study investigates time course changes of dendritic architectures in the stress vulnerable brain areas, the BLA and mPFC, and their behavioral consequences after acute treatment with a single dose of CORT.

RESULTS

Acute CORT treatment produced delayed onset of dendritic remodeling in the opposite direction in the BLA and mPFC with different time courses. Acute CORT induced dendritic hypertrophy of BLA spiny neurons, which was paralleled by heightened anxiety, both peaked 12 days after the treatment. Meanwhile, CORT-induced dendritic atrophy of mPFC pyramidal neurons peaked on day 6, concomitantly with impaired working memory. Both changed dendritic morphologies and altered behavioral outcomes were fully recovered.

CONCLUSION

Our results suggest that stress-induced heightened anxiety appears to be a functional consequence of dendritic remodeling of BLA neurons but not that of mPFC. Instead, stress-induced dendritic atrophy of mPFC neurons is relevant to working memory deficit. Therefore, structural changes in the BLA and the mPFC might be specifically associated with distinct behavioral symptoms observed in stress-related mental disorders. Remarkably, stress-induced dendritic remodeling in the BLA as well as mPFC is readily reversible. The related behavioral outcomes also follow the similar time course in a reversible manner. Therefore, further studies on the cellular mechanism for the plasticity of dendrites architecture might provide new insight into the etiological factors for stress-related mental illness such as posttraumatic stress disorder (PTSD).

Frontal-insula gray matter deficits in first-episode medication-naïve patients with major depressive disorder

OBJECTIVE

This study is designed to investigate the gray matter volume (GMV) deficits in patients with first-episode medication-naïve major depressive disorder (MDD).

METHODS

We enrolled 38 patients with first-episode medication-naïve MDD and 27 controls in this project. Voxel-based morphometry was used to compare GMV differences between two groups. Besides, the relationship between GMV of patients and the severity of clinical symptoms was estimated to confirm the role of GMV deficits in clinical symptoms. The correlation between total GMV and illness duration was also performed to elucidate the impacts of untreated duration on the GMV.

RESULTS

We found that first-episode medication-naïve MDD patients had significant GMV deficits in bilateral superior frontal gyri, left middle frontal gyrus, left medial frontal gyrus and left insula. The GMV of patient group was negatively correlated with the severity of clinical symptoms and the illness duration.

CONCLUSION

A pattern of GMV deficits in fronto-insula might represent the biomarker for first-episode medication-naïve MDD.

Functional connectivity in major depression: increased phase synchronization between frontal cortical EEG-source estimates

Structural and metabolic alterations in prefrontal brain areas, including the subgenual (SGPFC), medial (MPFC) and dorsolateral prefrontal cortex (DLPFC), have been shown in major depressive disorder (MDD). Still it remains largely unknown how brain connectivity within these regions is altered at the level of neuronal oscillations. Therefore, the goal was to analyze prefrontal electroencephalographic phase synchronization in MDD and its changes after antidepressant treatment. In 60 unmedicated patients and 60 healthy controls (HC), a 15-min resting electroencephalogram (EEG) was recorded in subjects at baseline and in a subgroup of patients after 2 weeks of antidepressant medication. EEG functional connectivity between the SGPFC and the MPFC/DLPFC was assessed with eLORETA (low resolution brain electromagnetic tomography) by means of lagged phase synchronization. At baseline, patients revealed increased prefrontal connectivity at the alpha frequency between the SGPFC and the left DLPFC/MPFC. After treatment, an increased connectivity between the SGPFC and the right DLPFC/MPFC at the beta frequency was found for MDD. A positive correlation was found for baseline beta connectivity and reduction in scores on the Hamilton depression rating scale. MDD is characterized by increased EEG functional connectivity within frontal brain areas. These EEG markers of disturbed neuronal communication might have potential value as biomarkers.

The structure of the geriatric depressed brain and response to electroconvulsive therapy

Electroconvulsive therapy (ECT) is the treatment of choice in severe geriatric depression. High remission rates may be influenced by specific brain morphology characteristic of geriatric depression. Our objective was to identify the relationship between brain structure, symptom profile, and ECT response. In a naturalistic cohort of 55 patients with a major depressive disorder, structural magnetic resonance imaging (MRI) was performed before ECT. Voxel-based morphometry was applied to determine regional differences in gray matter (GM) volume between patients and 23 matched healthy controls. Depressed patients with psychotic symptoms showed significantly higher remission rates and smaller regional GM volume of the left inferior frontal gyrus (IFG). Patients with late onset depression showed smaller regional GM volume of the bilateral lateral temporal cortex. Larger size of response in the whole patient group was related to smaller pretreatment regional GM volume of the right lateral temporal cortex, whereas faster speed of response was related to smaller pretreatment regional GM volume of the right IFG. ECT is most effective in depressed patients with psychotic symptoms. In this study the presence of psychotic symptoms was related to pretreatment smaller GM volume of the left IFG and bilateral temporal cortex. Smaller volume of the IFG pretreatment was related to faster treatment response, and smaller volume of the right lateral temporal cortex pretreatment was related to larger response to ECT. These results are possibly explained by the connectivity between these brain regions and an interconnected network that is particularly activated by the ECT-induced seizures.

The common traits of the ACC and PFC in anxiety disorders in the DSM-5: meta-analysis of voxel-based morphometry studies

Background

The core domains of social anxiety disorder (SAD), generalized anxiety disorder (GAD), panic disorder (PD) with and without agoraphobia (GA), and specific phobia (SP) are cognitive and physical symptoms that are related to the experience of fear and anxiety. It remains unclear whether these highly comorbid conditions that constitute the anxiety disorder subgroups of the Diagnostic and Statistical Manual for Mental Disorders – Fifth Edition (DSM-5) represent distinct disorders or alternative presentations of a single underlying pathology.

Methods

A systematic search of voxel-based morphometry (VBM) studies of SAD, GAD, PD, GA, and SP was performed with an effect-size signed differential mapping (ES-SDM) meta-analysis to estimate the clusters of significant gray matter differences between patients and controls.

Results

Twenty-four studies were eligible for inclusion in the meta-analysis. Reductions in the right anterior cingulate gyrus and the left inferior frontal gyrus gray matter volumes (GMVs) were noted in patients with anxiety disorders when potential confounders, such as comorbid major depressive disorder (MDD), age, and antidepressant use were controlled for. We also demonstrated increased GMVs in the right dorsolateral prefrontal cortex (DLPFC) in comorbid depression-anxiety (CDA), drug-naïve and adult patients. Furthermore, we identified a reduced left middle temporal gyrus and right precentral gyrus in anxiety patients without comorbid MDD.

Conclusion

Our findings indicate that a reduced volume of the right ventral anterior cingulate gyrus and left inferior frontal gyrus is common in anxiety disorders and is independent of comorbid depression, medication use, and age. This generic effect supports the notion that the four types of anxiety disorders have a clear degree of overlap that may reflect shared etiological mechanisms. The results are consistent with neuroanatomical DLPFC models of physiological responses, such as worry and fear, and the importance of the ventral anterior cingulate (ACC)/medial prefrontal cortex (mPFC) in mediating anxiety symptoms.

The Behavioural Inhibition System, anxiety and hippocampal volume in a non-clinical population

Background

Animal studies have suggested that the hippocampus may play an important role in anxiety as part of the Behavioural Inhibition System (BIS), which mediates reactivity to threat and punishment and can predict an individual’s response to anxiety-relevant cues in a given environment. The aim of the present structural magnetic resonance imaging (MRI) study was to examine the relationship between individual differences in BIS and hippocampal structure, since this has not received sufficient attention in non-clinical populations. Thirty healthy right-handed participants with no history of alcohol or drug abuse, neurological or psychiatric disorders, or traumatic brain injury were recruited (16 male, 14 female, age 18 to 32 years). T1-weighted structural MRI scans were used to derive estimates of total intracranial volume, and hippocampal and amygdala gray matter volume using FreeSurfer. To relate brain structure to Gray’s BIS, participants completed the Sensitivity to Punishment questionnaire. They also completed questionnaires assessing other measures potentially associated with hippocampal volume (Beck Depression Inventory, Negative Life Experience Survey), and two other measures of anxiety (Spielberger Trait Anxiety Inventory and the Beck Anxiety Inventory).

Results

We found that high scores on the Sensitivity to Punishment scale were positively associated with hippocampal volume, and that this phenomenon was lateralized to the right side. In other words, greater levels of behavioural inhibition (BIS) were positively associated with right hippocampal volume.

Conclusions

Our data suggest that hippocampal volume is related to the cognitive and affective dimensions of anxiety indexed by the Sensitivity to Punishment, and support the idea that morphological differences in the hippocampal formation may be associated with behavioural inhibition contributions to anxiety.

Limbic system white matter microstructure and long-term treatment outcome in major depressive disorder: a diffusion tensor imaging study using legacy data

OBJECTIVES

Treatment-resistant depression is a common clinical occurrence among patients with major depressive disorder (MDD), but its neurobiology is poorly understood. We used data collected as part of routine clinical care to study white matter integrity of the brain's limbic system and its association to treatment response.

METHODS

Electronic medical records of multiple large New England hospitals were screened for patients with an MDD billing diagnosis, and natural language processing was subsequently applied to find those with concurrent diffusion-weighted images, but without any diagnosed brain pathology. Treatment outcome was determined by review of clinical charts. MDD patients (n = 29 non-remitters, n = 26 partial-remitters, and n = 37 full-remitters), and healthy control subjects (n = 58) were analyzed for fractional anisotropy (FA) of the fornix and cingulum bundle.

RESULTS

Failure to achieve remission was associated with lower FA among MDD patients, statistically significant for the medial body of the fornix. Moreover, global and regional-selective age-related FA decline was most pronounced in patients with treatment-refractory, non-remitted depression.

CONCLUSIONS

These findings suggest that specific brain microstructural white matter abnormalities underlie persistent, treatment-resistant depression. They also demonstrate the feasibility of investigating white matter integrity in psychiatric populations using legacy data.

Emotional and behavioral symptoms in neurodegenerative disease: a model for studying the neural bases of psychopathology

Disruptions in emotional, cognitive, and social behavior are common in neurodegenerative disease and in many forms of psychopathology. Because neurodegenerative diseases have patterns of brain atrophy that are much clearer than those of psychiatric disorders, they may provide a window into the neural bases of common emotional and behavioral symptoms. We discuss five common symptoms that occur in both neurodegenerative disease and psychopathology (i.e., anxiety, dysphoric mood, apathy, disinhibition, and euphoric mood) and their associated neural circuitry. We focus on two neurodegenerative diseases (i.e., Alzheimer's disease and frontotemporal dementia) that are common and well characterized in terms of emotion, cognition, and social behavior and in patterns of associated atrophy. Neurodegenerative diseases provide a powerful model system for studying the neural correlates of psychopathological symptoms; this is supported by evidence indicating convergence with psychiatric syndromes (e.g., symptoms of disinhibition associated with dysfunction in orbitofrontal cortex in both frontotemporal dementia and bipolar disorder). We conclude that neurodegenerative diseases can play an important role in future approaches to the assessment, prevention, and treatment of mental illness.

Diagnostic and therapeutic utility of neuroimaging in depression: an overview

A growing number of studies have used neuroimaging to further our understanding of how brain structure and function are altered in major depression. More recently, these techniques have begun to show promise for the diagnosis and treatment of depression, both as aids to conventional methods and as methods in their own right. In this review, we describe recent neuroimaging findings in the field that might aid diagnosis and improve treatment accuracy. Overall, major depression is associated with numerous structural and functional differences in neural systems involved in emotion processing and mood regulation. Furthermore, several studies have shown that the structure and function of these systems is changed by pharmacological and psychological treatments of the condition and that these changes in candidate brain regions might predict clinical response. More recently, "machine learning" methods have used neuroimaging data to categorize individual patients according to their diagnostic status and predict treatment response. Despite being mostly limited to group-level comparisons at present, with the introduction of new methods and more naturalistic studies, neuroimaging has the potential to become part of the clinical armamentarium and may improve diagnostic accuracy and inform treatment choice at the patient level.

Unique and interactive effect of anxiety and depressive symptoms on cognitive and brain function in young and older adults

OBJECTIVE

Depression and anxiety and are associated with cognitive deficits and brain changes, especially in older adults. Despite the frequent co-occurrence of these conditions, cognitive neuroscience studies examining comorbid depression and anxiety are limited. The goal of the present study was to examine the unique and combined effect of depressive and anxiety symptoms on cognitive and brain functioning in young and older adults.

METHODS

Seventy-one healthy, community-dwelling adults between the ages of 18 and 81 were administered a neuropsychological battery and completed the Center for Epidemiologic Studies Depression Scale (CES-D) and the trait form of the State-Trait Anxiety Inventory (STAI-T). A subset of 25 participants also underwent functional magnetic resonance imaging (fMRI) scanning while completing the n-back working memory task.

RESULTS

Total depressive symptoms, depressed mood symptoms, and somatic symptoms were associated with deficits in speed, working memory and executive functions, especially in older adults. Symptoms of lack of well-being were not associated with any neuropsychological test. Anxiety was associated with better attention and working memory. Moreover, anxiety modified the relationship between depressive symptoms and executive functioning in older adults, as elevated depressive symptoms were associated with worse performance at low levels of anxiety, but not at higher anxiety levels. Similarly, analysis of fMRI data showed that total depressive symptoms and depressed mood symptoms were associated with decreased activity in the superior frontal gyrus at low anxiety levels, but not at high anxiety levels.

CONCLUSION

Results confirm previous reports that subthreshold depression and anxiety impact cognitive and brain functioning and suggest that the interaction of depression and anxiety results in distinct cognitive and brain changes. Findings highlight the importance of assessing and controlling for symptoms of depression and anxiety in research studies of either condition.

Bridging intimate partner violence and the human brain: a literature review

Past studies mainly focused on the physical and structural brain injuries in women survivors with a history of intimate partner violence (IPV), but little attention has been given to the biological impact and cognitive dysfunction resulting from such psychological stress. In this article, we aim to establish the connection between IPV and the brain by reviewing current literature examining (1) the biological mechanisms linking IPV, stress, and the brain; (2) the functional and anatomical considerations of the brain in abused women; and (3) the abused women's behavioral responses to IPV, including fear, pain, and emotion regulation, by utilizing functional neuroimaging. The major significance of this study is in highlighting the need to advance beyond self-reports and to obtain scientific evidence of the neurological impact and cognitive dysfunction in abused women with a history of IPV, an area in which current literature remains at a descriptive level.

Family history of alcohol dependence and gray matter abnormalities in non-alcoholic adults

OBJECTIVES

Alcohol-use disorders in adolescents are associated with gray matter (GM) abnormalities suggesting neurotoxicity by alcohol. However, recently similar GM abnormalities were found in non-drinking children with a family history (FH) of alcohol dependence (AD). The question thus rises whether these abnormalities represent a transient delay in brain maturation or a persistent risk factor for developing neuropsychiatric disorders, rather than a (neurotoxic) consequence of AD. This study investigated whether a FH of AD in non-drinking adults is associated with abnormal GM-volumes similar to those observed in drinking and non-drinking adolescents with a FH of AD.

METHODS

GM-images were analyzed using Voxel-Based Morphometry in non-alcoholics with (FH+; N = 36) and without (FH-; N = 107) familial AD. Additionally we controlled for possible confounders: diagnosis of depression/anxiety, childhood trauma and familial depression/anxiety.

RESULTS

Smaller GM-volumes were shown in the right parahippocampal gyrus in FH+ compared with FH-. Results were unaffected by confounders.

CONCLUSIONS

We demonstrated an effect of familial AD in non-alcoholic adults on GM volume in the parahippocampal gyrus, similar to drinking and non-drinking FH+ adolescents. These findings suggest that GM abnormalities in the parahippocampal gyrus represent a persistent biological susceptibility for AD or related psychopathology and not neurotoxicity of alcohol or delayed brain maturation.

State-dependent changes in hippocampal grey matter in depression

Reduced hippocampal volume has been reported in depression and may be involved in the aetiology of depressive symptoms and vulnerability to depressive relapse. Neuroplasticity following antidepressant drug treatment in the hippocampus has been demonstrated in animal models but adaptive changes after such treatment have not been shown in humans. In this study, we determined whether grey matter loss in the hippocampus in depression (1) is present in medication-free depressed (2) changes in response to antidepressant treatment and (3) is present as a stable trait in medication-free remitted patients. Sixty-four medication-free unipolar depressed patients: 39 currently depressed and 25 in remission, and 66 healthy controls (HC) underwent structural magnetic resonance imaging in a cross-sectional and longitudinal design. Thirty-two currently depressed participants were then treated with the antidepressant citalopram for 8 weeks. Adherence to treatment was evaluated by measuring plasma citalopram concentration. We measured regional variation in grey matter concentration by using voxel-based morphometry-Diffeomorphic Anatomical Registration Through Exponentiated Lie algebra. Patients with current depression had bilaterally reduced grey matter in the hippocampus compared with HC and untreated patients in stable remission with the latter groups not differing. An increase in grey matter was observed in the hippocampus following treatment with citalopram in currently depressed patients. Grey matter reduction in the hippocampus appears specific to the depressed state and is a potential biomarker for a depressive episode.

Cortical thickness, surface area, and gyrification abnormalities in children exposed to maltreatment: neural markers of vulnerability?

BACKGROUND

Childhood maltreatment has been shown to significantly elevate the risk of psychiatric disorder. Previous neuroimaging studies of children exposed to maltreatment have reported atypical neural structure in several regions, including the prefrontal cortex and temporal lobes. These studies have exclusively investigated volumetric differences rather than focusing on genetically and developmentally distinct indices of brain structure.

METHODS

Here we used surface-based methods to examine cortical thickness, surface area, and local gyrification in a community sample of children with documented experiences of abuse (n = 22) and a group of carefully matched nonmaltreated peers (n = 21).

RESULTS

Reduced cortical thickness in the maltreated compared with the nonmaltreated group was observed in an extended cluster that incorporated the anterior cingulate, superior frontal gyrus, and orbitofrontal cortex. In addition, reduced cortical surface area was observed within the parcellated regions of the left middle temporal area and lingual gyrus. Local gyrification deficits within the maltreated group were located within two clusters, the lingual gyrus and the insula extending into pars opercularis.

CONCLUSIONS

This is the first time structural abnormalities in the anterior cingulate and lingual gyrus have been detected in children exposed to maltreatment. Surface-based methods seem to capture subtle, previously undetected, morphological abnormalities associated with maltreatment. We suggest that these approaches detect developmental precursors of brain volume differences seen in adults with histories of abuse. Because the reported regions are implicated in several clinical disorders, they might constitute biological markers of vulnerability, linking exposure to early adversity and psychiatric risk.

Smaller grey matter volumes in the anterior cingulate cortex and greater cerebellar volumes in patients with long-term remission of Cushing's disease: a case-control study

OBJECTIVE

Patients with long-term remission of Cushing's disease (CD) have persistent psychological and cognitive impairments. It is unknown whether, and to what extent, these impairments are accompanied by structural abnormalities in the brain. We aim to investigate structural changes in the brain in patients with predominantly long-term remission of CD and to examine whether these changes are associated with psychological and cognitive dysfunction and clinical severity.

DESIGN

A cross-sectional, case-control study.

METHODS

In 25 patients with predominantly long-term remission of CD and 25 matched healthy controls, grey matter volumes in the regions of interest (hippocampus, amygdala, and anterior cingulate cortex (ACC)) and in the whole brain were examined, using 3T magnetic resonance imaging and a voxel-based morphometry approach. Psychological and cognitive functioning were assessed using validated questionnaires and clinical severity was assessed using the Cushing's syndrome severity index.

RESULTS

Compared with controls, patients had smaller grey matter volumes of areas in the ACC (on average 14%, P<0.05) and greater volume of the left posterior lobe of the cerebellum (on average 34%, P<0.05). As expected, patients with remitted CD reported more depressive symptoms (P=0.005), more anxiety (P=0.003), more social phobia (P=0.034), more apathy (P=0.002), and more cognitive failure (P=0.023) compared with controls, but the differences in grey matter volumes were not associated with psychological or cognitive measures, nor with clinical severity.

CONCLUSION

Patients with predominantly long-term remission of CD showed specific structural brain abnormalities, in the presence of psychological dysfunction. Our data form a basis for future work aimed at elucidating the relation of the structural brain abnormalities and the sustained psychological deficits after long-term exposure to high cortisol levels.

Changes in regional homogeneity of parieto-temporal regions in panic disorder patients who achieved remission with antidepressant treatment

OBJECTIVE

This study was aimed to study the treatment effects of antidepressant for regional homogeneity (ReHo), an indicator of synchronization of brain function, in panic disorder (PD) patients.

METHOD

Twenty-one remitted PD patients with escitalopram treatment and 21 healthy controls all received 3-T magnetic resonance imaging scanning at baseline and sixth week. We utilized REST (Resting State FMRI Data Analysis Toolkit, version 1.4) to calculate regional homogeneity (ReHo) of patients and controls at baseline and sixth week. We compared the ReHo at baseline with the ReHo at sixth week to estimate the treatment effects for the ReHo of remitted patients. Besides, inter-scan effects were evaluated in the control group. The group-related differences between remitted patients and controls were also estimated.

RESULTS

Remitted PD patients had increases in ReHo of right Heschl gyrus (superior temporal lobe) and decreases in ReHo of right angular gyrus (parietal lobe). The improvements in severity of panic symptoms were negatively correlated with the changes of ReHo in right superior parietal lobe. However, remitted patients still had lower ReHo than controls in right Heschl gyrus and left thalamus.

CONCLUSION

The changes in ReHo of temporo-parietal regions might represent treatment-related ReHo changes for remission of PD. The residual alterations in ReHo of temporo-thalamic regions might represent group-related ReHo differences for patients with PD.

Altered cortical gyrification patterns in panic disorder: deficits and potential compensation

Abnormal gyrification patterns may reflect aberrant cortical connectivity during an early period of brain maturation. We here investigated anatomical distribution of cortical gyrification deficits underlying panic disorder and the relationships of these potential neurodevelopmental markers with panic symptom severity. High-resolution three-dimensional T1-weighted structural images were obtained from 23 patients with panic disorder and 33 matched healthy individuals. Local gyrification indices were measured in each genetically-based parcellated cortical subregion and regional gyrification patterns were compared between groups. Cortical areas in which gyrification patterns were associated with panic symptom severity were also determined. Significant reductions in cortical gyrification were observed in panic patients compared with healthy individuals, which were mainly distributed in the lateral brain extending from the fronto-parietal to the temporal areas. In contrast, hyper-gyrification in the posteromedial cortical regions which exert interconnecting roles in the default mode network, was associated with less severe panic symptoms. Post-hoc analysis for the inter-regional covariance of local gyrification indices revealed that interconnections of the posteromedial cortical regions with other cortical areas which belong to the default mode network were reduced in panic patients with severe symptoms relative to either less severe patients or healthy individuals. Our findings suggest not only substantial perturbation in cortical gyrification patterns in panic disorder but also potential contribution of integrated cortical folding pattern of the default mode network to alleviated panic severity.

Localized brain volume and white matter integrity alterations in adolescent anorexia nervosa

OBJECTIVE

The neurobiological underpinnings of anorexia nervosa (AN) are poorly understood. In this study, we tested whether brain gray matter (GM) and white matter (WM) in adolescents with AN would show alterations comparable to those in adults.

METHOD

We used magnetic resonance imaging to study GM and WM volume, and diffusion tensor imaging to assess fractional anisotropy for WM integrity in 19 adolescents with AN and 22 controls.

RESULTS

Individuals with AN showed greater left orbitofrontal, right insular, and bilateral temporal cortex GM, as well as temporal lobe WM volumes compared to controls. WM integrity in adolescents with AN was lower (lower fractional anisotropy) in fornix, posterior frontal, and parietal areas, but higher in anterior frontal, orbitofrontal, and temporal lobes. In individuals with AN, orbitofrontal GM volume correlated negatively with sweet taste pleasantness. An additional comparison of this study cohort with adult individuals with AN and healthy controls supported greater orbitofrontal cortex and insula volumes in AN across age groups.

CONCLUSIONS

This study indicates larger orbitofrontal and insular GM volumes, as well as lower fornix WM integrity in adolescents with AN, similar to adults. The pattern of larger anteroventral GM and WM volume as well as WM integrity, but lower WM integrity in posterior frontal and parietal regions may indicate that developmental factors such as GM pruning and WM growth could contribute to brain alterations in AN. The negative correlation between taste pleasantness and orbitofrontal cortex volume in individuals with AN could contribute to food avoidance in this disorder.

Increased cortical thickness in a frontoparietal network in social anxiety disorder

Social anxiety disorder (SAD) is the second leading anxiety disorder. On the functional neurobiological level, specific brain regions involved in the processing of anxiety-laden stimuli and in emotion regulation have been shown to be hyperactive and hyper-responsive in SAD such as amygdala, insula and orbito- and prefrontal cortex. On the level of brain structure, prior studies on anatomical differences in SAD resulted in mixed and partially contradictory findings. Based on previous functional and anatomical models of SAD, this study examined cortical thickness in structural magnetic resonance imaging data of 46 patients with SAD without comorbidities (except for depressed episode in one patient) compared with 46 matched healthy controls in a region of interest-analysis and in whole-brain. In a theory-driven ROI-analysis, cortical thickness was increased in SAD in left insula, right anterior cingulate and right temporal pole. Furthermore, the whole-brain analysis revealed increased thickness in right dorsolateral prefrontal and right parietal cortex. This study detected no regions of decreased cortical thickness or brain volume in SAD. From the perspective of brain networks, these findings are in line with prior functional differences in salience networks and frontoparietal networks associated with executive-controlling and attentional functions.

Neurobiology of neuropsychiatric symptoms in Alzheimer's disease: A critical review with a focus on neuroimaging

The objective of this critical review of the literature was to reveal the neural circuits involved in the occurrence of neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) patients through the association of these symptoms with neuroimaging findings. The search for articles was performed on PUBMED from January 2000 to May 2013, using the key words: Dementia AND BPSD; Dementia AND Neuropsychiatric Symptoms; and Dementia AND Psychosis, Delusions, Hallucinations, Agitation, Depression, Anxiety, Apathy, Euphoria, Disinhibition, Irritability, Aberrant Motor Behavior, Sleep or Eating Disorders. Forty-six articles were reviewed and important contributions, especially regarding the psychopathological concepts discussed, were also considered even if not included in this time period. The available evidence suggests the three most relevant neurobiological models for neuropsychiatric symptoms in Alzheimer's disease are the frontal-subcortical circuits, the cortico-cortical networks, and the monoaminergic system. We discussed the association of the individual symptoms or syndromes with these models.

Gray matter and intrinsic network changes in the posterior cingulate cortex after selective serotonin reuptake inhibitor intake

Preclinical studies have demonstrated that serotonin (5-HT) challenge changes neuronal circuitries and microarchitecture. However, evidence in human subjects is missing. Pharmacologic magnetic resonance imaging (phMRI) applying selective 5-HT reuptake inhibitors (SSRIs) and high-resolution structural and functional brain assessment is able to demonstrate the impact of 5-HT challenge on neuronal network morphology and functional activity. To determine how SSRIs induce changes in gray matter and neuronal activity, we conducted a longitudinal study using citalopram and escitalopram. Seventeen healthy subjects completed a structural and functional phMRI study with randomized, cross-over, placebo-controlled, double-blind design. Significant gray matter increases were observed (among other regions) in the posterior cingulate cortex (PCC) and the ventral precuneus after SSRI intake of 10days, while decreases were observed within the pre- and postcentral gyri (all P<0.05, family-wise error [FWE] corrected). Furthermore, enhanced resting functional connectivity (rFC) within the ventral precuneus and PCC was associated with gray matter increases in the PCC (all FWE Pcorr<0.05). Corroborating these results, whole-brain connectivity density, measuring the brain's functional network hubs, was significantly increased after SSRI-intake in the ventral precuneus and PCC (all FWE Pcorr<0.05). Short-term administration of SSRIs changes gray matter structures, consistent with previous work reporting enhancement of neuroplasticity by serotonergic neurotransmission. Furthermore, increased gray matter in the PCC is associated with increased functional connectivity in one of the brain's metabolically most active regions. Our novel findings provide convergent evidence for dynamic alterations of brain structure and function associated with SSRI pharmacotherapy.

Regional gray matter reductions are associated with genetic liability for anxiety and depression: an MRI twin study

BACKGROUND

The influence of genetic and/or environmental factors on the volumetric brain changes observed in subjects affected by anxiety and depression disorders remains unclear. The current study aimed to investigate whether genetic and environmental liabilities make different contributions to abnormalities in gray matter volume (GMV) in anxiety and depression using a concordant and discordant MZ twin pairs design.

METHODS

Fifty-three magnetic resonance imaging (3T) brain scans were obtained from monozygotic (MZ) twins concordant (6 pairs) and discordant (10 pairs) for lifetime anxiety and depression disorders and from healthy twins (21 subjects). We applied voxel-based morphometry to analyse GMV differences. Concordant affected twins were compared to healthy twins and within-pairs comparisons were performed in the discordant group.

RESULTS

GMV reductions in bilateral fusiform gyrus and amygdala were observed in concordant affected twins for anxiety and depression compared to healthy twins. No intrapair differences were found in GMV between discordant affected twins and their healthy co-twins.

LIMITATIONS

The sample size was modest. This might explain why no intrapair differences were found in the discordant MZ twin group.

CONCLUSIONS

As concordant affected MZ twins are believed to have a particularly high genetic liability for the disorder, our findings suggest that fusiform gyrus and amygdala gray matter reductions are related to a genetic risk for anxiety and depression. Discrepancies in regard to brain abnormalities in anxiety and depression may be related to the admixture of patients with GMV abnormalities mainly accounted for by genetic factors with patients presenting GMV mainly accounted for by environmental factors.

Family history of alcohol dependence modulates functional neurophysiology in mood/anxiety disorders

BACKGROUND

A family history (FH) of alcohol dependence (AD) not only increases the risk for AD, but is also associated with an increased risk for mood and anxiety disorders. However, it is unknown how a FH of AD affects neural substrates in patients with mood and anxiety disorders. In this study we examined the effects of an alcoholic FH on cognitive and emotional functions in these patients using functional magnetic resonance imaging (fMRI). Method In a sample of non-alcoholic patients with depressive and/or anxiety disorders from the Netherlands Study of Depression and Anxiety (NESDA) neuroimaging study, patients with a first-degree FH of AD (FH + ; n = 31) were compared with patients without a FH (FH-; n = 77) on performance and brain activation during visuospatial planning and emotional word encoding. Results were compared with those of healthy controls (HCs) without a FH of AD (n = 31).

RESULTS

FH+ patients performed slower during planning with increasing task load, coupled with stronger blood oxygen level-dependent responses in dorsal prefrontal areas compared with FH- patients and HCs. FH was not associated with performance differences during word encoding, but right insula activation during positive word encoding was present in FH+ patients, comparable with HCs, but absent in FH- patients.

CONCLUSIONS

This study demonstrates subtle impairments during planning in FH+ compared with FH- patients and HCs, whereas activation during mood-incongruent stimuli in FH+ patients was similar to HCs but not FH- patients, suggesting that the presence of a FH of AD is a useful marker for the neurophysiological profile in mood/anxiety disorders and possible predictor for treatment success.

Influence of the topography of brain damage on depression and fatigue in patients with multiple sclerosis

Objectives:

Involvement of selected central nervous system (CNS) regions has been associated with depression and fatigue in MS. We assessed whether specific regional patterns of lesion distribution and atrophy of the gray (GM) and white matter (WM) are associated with these symptoms in MS.

Methods:

Brain dual-echo and 3D T1-weighted images were acquired from 123 MS patients (69 depressed (D), 54 non-depressed (nD), 64 fatigued, 59 non-fatigued) and 90 controls. Lesion distribution, GM and WM atrophy were estimated using VBM and SPM8.

Results:

Gender, age, disease duration and conventional MRI characteristics did not differ between D-MS and nD-MS patients. Fatigued patients experienced higher EDSS and depression than non-fatigued ones. Lesion distribution and WM atrophy were not related to depression and fatigue. Atrophy of regions in the frontal, parietal and occipital lobes had a combined effect on depression and fatigue. Atrophy of the left middle frontal gyrus and right inferior frontal gyrus were selectively related to depression. No specific pattern of GM atrophy was found to be related to fatigue.

Conclusions:

Depression in MS is linked to atrophy of cortical regions located in the bilateral frontal lobes. A distributed pattern of GM atrophy contributes to the concomitant presence of depression and fatigue in these patients.

Whole-brain functional connectivity during emotional word classification in medication-free Major Depressive Disorder: Abnormal salience circuitry and relations to positive emotionality

Major Depressive Disorder (MDD) has been associated with biased processing and abnormal regulation of negative and positive information, which may result from compromised coordinated activity of prefrontal and subcortical brain regions involved in evaluating emotional information. We tested whether patients with MDD show distributed changes in functional connectivity with a set of independently derived brain networks that have shown high correspondence with different task demands, including stimulus salience and emotional processing. We further explored if connectivity during emotional word processing related to the tendency to engage in positive or negative emotional states. In this study, 25 medication-free MDD patients without current or past comorbidity and matched controls (n = 25) performed an emotional word-evaluation task during functional MRI. Using a dual regression approach, individual spatial connectivity maps representing each subject's connectivity with each standard network were used to evaluate between-group differences and effects of positive and negative emotionality (extraversion and neuroticism, respectively, as measured with the NEO-FFI). Results showed decreased functional connectivity of the medial prefrontal cortex, ventrolateral prefrontal cortex, and ventral striatum with the fronto-opercular salience network in MDD patients compared to controls. In patients, abnormal connectivity was related to extraversion, but not neuroticism. These results confirm the hypothesis of a relative (para)limbic–cortical decoupling that may explain dysregulated affect in MDD. As connectivity of these regions with the salience network was related to extraversion, but not to general depression severity or negative emotionality, dysfunction of this network may be responsible for the failure to sustain engagement in rewarding behavior.

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We studied whole-brain functional connectivity in MDD during an emotional task.

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We used a set of independent template networks, corresponding to various task demands.

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We showed lower connectivity of reward related regions with a salience network in MDD.

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Lower salience connectivity specifically related to extraversion in patients

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Results may reflect vulnerability for MDD via a circuit vital for rewarding behavior.

Anxious/depressed symptoms are linked to right ventromedial prefrontal cortical thickness maturation in healthy children and young adults

The relationship between anxious/depressed traits and neuromaturation remains largely unstudied. Characterizing this relationship during healthy neurodevelopment is critical to understanding processes associated with the emergence of child/adolescent onset mood/anxiety disorders. In this study, mixed-effects models were used to determine longitudinal cortical thickness correlates of Child Behavior Checklist (CBCL) and Young Adult Self Report Anxious/Depressed scores in healthy children. Analyses included 341 subjects from 4.9 to 22.3 year-old with repeated MRI at up to 3 time points, at 2-year intervals (586 MRI scans). There was a significant "CBCL Anxious/Depressed by Age" interaction on cortical thickness in the right ventromedial prefrontal cortex (vmPFC), including the medial orbito-frontal, gyrus rectus, and subgenual anterior cingulate areas. Anxious/Depressed scores were negatively associated with thickness at younger ages (<9 years), but positively associated with thickness at older ages (15-22 years), with the shift in polarity occurring around age 12. This was secondary to a slower rate of vmPFC cortical thinning in subjects with higher scores. In young adults (18-22 years), Anxious/Depressed scores were also positively associated with precuneus/posterior cingulate cortical thickness. Potential neurobiological mechanisms underlying this maturation pattern are proposed. These results demonstrate the dynamic impact of age on relations between vmPFC and negative affect in the developing brain.

Comparison of panic disorder with and without comorbid major depression by using brain structural magnetic resonance imaging

BACKGROUND

Strong lifetime and current comorbidity occur between panic disorder and depression. However, no study has examined the influence of comorbid depression on brain structural characteristics in panic disorder patients. We aimed to compare gray matter (GM) volume and white matter (WM) connectivity in panic disorder patients with and without depression.

METHODS

Twenty-one panic disorder patients without comorbid major depression (PD-D) and seventeen panic disorder patients with major depression (PD+D) were investigated. The Panic Disorder Severity Scale (PDSS) and Beck Depression Inventory (BDI) were assessed for all subjects. Voxel Based Morphometry 5 toolbox and Tract-Based Spatial Statistics were used.

RESULTS

Compared to the PD-D group, GM volumes of patients with PD+D were significantly increased in a cluster located across the left cingulate gyrus, right medial frontal gyrus, and left paracentral lobule. Clinical symptom severity such as PDSS and BDI scores showed positive correlation with GM volumes in the PD+D group. Of the highlighted regions, the left posterior cingulate gyrus demonstrated both a GM volume difference between the groups and a positive correlation of GM volume with symptom severity in the PD+D group. Fractional anisotropy values were significantly higher across almost all the WM tracts in the PD+D group compared to the PD-D group.

CONCLUSION

Alteration of GM volume and WM connectivity was associated with comorbid depression in panic disorder patients in this study. These findings suggest that distinct structural characteristics may be related to comorbid depression occurring in the context of panic disorder.

White matter integrity alterations in first episode, treatment-naive generalized anxiety disorder

BACKGROUND

Several neurobiological models of anxiety disorder posit a primary role for dysfunction of the amygdala and anterior cingulate cortex (ACC). This study tests the hypothesis that patients with generalized anxiety disorder (GAD) have abnormal white matter microstructure in the amygdala and ACC, as inferred from diffusion tensor imaging, compared with healthy controls.

METHODS

Subjects were 16 right-handed, first-episode, treatment-naive GAD patients without comorbid disorders and 26 matched, healthy comparison controls. All subjects underwent diffusion tensor imaging and structural magnetic resonance imaging brain scanning. Fractional anisotropy (FA), a robust intravoxel measure of water self-diffusion, was compared between groups on a voxel-by-voxel basis. Associations between clinical ratings of symptom severity (i.e., the Hamilton Anxiety Scale and the Penn State Worry Questionnaire) and FA were assessed.

RESULTS

Compared with healthy volunteers, patients demonstrated significantly higher FA in the right amygdala white matter and lower FA in the caudal ACC/mid-cingulate cortex white matter. Higher right amygdala FA correlated significantly with higher Hamilton Anxiety Scale scores and higher Penn State Worry Questionnaire scores.

LIMITATIONS

The sample size was modest and may contribute to false positive effects.

CONCLUSIONS

These findings provide the first evidence of an abnormality in white matter microstructure that involves the amygdala and the cingulate cortex in the pathogenesis of GAD, and are consistent with neurobiological models that posit a defect in emotion-related brain regions.

How cigarette smoking may increase the risk of anxiety symptoms and anxiety disorders: a critical review of biological pathways

Multiple studies have demonstrated an association between cigarette smoking and increased anxiety symptoms or disorders, with early life exposures potentially predisposing to enhanced anxiety responses in later life. Explanatory models support a potential role for neurotransmitter systems, inflammation, oxidative and nitrosative stress, mitochondrial dysfunction, neurotrophins and neurogenesis, and epigenetic effects, in anxiety pathogenesis. All of these pathways are affected by exposure to cigarette smoke components, including nicotine and free radicals. This review critically examines and summarizes the literature exploring the role of these systems in increased anxiety and how exposure to cigarette smoke may contribute to this pathology at a biological level. Further, this review explores the effects of cigarette smoke on normal neurodevelopment and anxiety control, suggesting how exposure in early life (prenatal, infancy, and adolescence) may predispose to higher anxiety in later life. A large heterogenous literature was reviewed that detailed the association between cigarette smoking and anxiety symptoms and disorders with structural brain changes, inflammation, and cell-mediated immune markers, markers of oxidative and nitrosative stress, mitochondrial function, neurotransmitter systems, neurotrophins and neurogenesis. Some preliminary data were found for potential epigenetic effects. The literature provides some support for a potential interaction between cigarette smoking, anxiety symptoms and disorders, and the above pathways; however, limitations exist particularly in delineating causative effects. The literature also provides insight into potential effects of cigarette smoke, in particular nicotine, on neurodevelopment. The potential treatment implications of these findings are discussed in regards to future therapeutic targets for anxiety. The aforementioned pathways may help mediate increased anxiety seen in people who smoke. Further research into the specific actions of nicotine and other cigarette components on these pathways, and how these pathways interact, may provide insights that lead to new treatment for anxiety and a greater understanding of anxiety pathogenesis.

White matter volume in alcohol use disorders: a meta-analysis

Atrophy of brain white matter (WM) often is considered a signature injury of alcohol use disorders (AUDs). However, investigations into AUD-related changes in WM volume have yielded complex findings that are difficult to synthesize in a narrative review. The objective of this study was to obtain an averaged effect size (ES) for WM volume reduction associated with AUD diagnosis and to test potential moderators of ES. Study inclusion criteria were: (1) English language; (2) peer reviewed; (3) published before December 2011; (4) use of magnetic resonance imaging (MRI); (5) human participants; (6) inclusion of AUD group; (7) inclusion of non-AUD comparison group; and (8) reporting or testing of total or cerebral WM volume. Moderators included study design, MRI methodology and AUD characteristics. Nineteen studies with a total of 1302 participants (70% male) were included, and calculated ESs were confirmed by the corresponding author for 12 studies. The magnitude of the averaged ES adjusted for small sample bias (Hedges' g) for WM reduction in AUDs was 0.304 (standard error = 0.134, range = -0.57-1.21). Hierarchical linear modeling indicated that the overall ES differed significantly from 0, t(18) = 2.257, P = 0.037, and that the distribution of the 19 ESs showed significant heterogeneity beyond sampling error, χ(2) (18) = 52.400, P < 0.001. Treatment-seeking status and length of abstinence were significant moderators of ES distribution. These results are suggestive of WM recovery with sustained abstinence and point to the need for further investigation of factors related to treatment-seeking status.

Deficits in cortical, diencephalic and midbrain gray matter in alcoholism measured by VBM: Effects of co-morbid substance abuse

Objective

Alcoholism has been associated with a widespread pattern of gray matter atrophy. This study sought to investigate the spectrum of volume alterations in a population of alcoholics with only alcohol dependence, polysubstance abusing alcoholics, and a comparison population of healthy controls.

Method

Thirty-seven ‘pure’ alcoholics, 93 polysubstance abusing alcoholics, and 69 healthy controls underwent structural T1 MRI scans. Voxel-based morphometry was performed to investigate gray matter alterations.

Results

Alcoholic dependent inpatients (both with and without a history of DSM-IV substance abuse/dependence diagnosis) displayed significant gray matter differences in the mesial region of the frontal lobe and right temporal lobe. ‘Pure’ alcoholics exhibited a pattern of subcortical changes similar to that seen in Wernicke–Korsakoff Syndrome when compared to polysubstance abusing alcoholics. ‘Pure’ alcoholics and polysubstance abusing alcoholics did not differ significantly in measures of cortical gray matter, liver function, or nutrition.

Conclusions

These findings reinforce the accepted literature in regards to frontal lobe gray matter atrophy in alcohol dependence. This study calls for additional research in order to investigate the spectrum from uncomplicated alcoholism to Wernicke–Korsakoff Syndrome. Further research is needed to elucidate the exact cause of this pattern of differences and to determine what factors are responsible for the patterns of gray matter reduction or difference in ‘pure’ and polysubstance abusing alcoholics.

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Large scale voxel-based morphometry study on alcoholics and healthy controls.

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Alcoholics display less gray matter in the mesial frontal lobe and the temporal lobe.

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“Pure” alcoholics show a pattern of deficit similar to that of Wernicke's Encephalopathy.

Neurobiology of anxious depression: a review

Anxious depression is a common, distinct clinical subtype of major depressive disorder (MDD). This review summarizes current neurobiological knowledge regarding anxious depression. Peer-reviewed articles, published January 1970 through September 2012, were identified via PUBMED, EMBASE, and Cochrane Library, using the following key words: anxious depression electroencephalography (EEG), anxious depression functional magnetic resonance imaging (fMRI), anxious depression genetics, anxious depression neurobiology, and anxious melancholia neurobiology. Despite a general dearth of neurobiological research, the results suggest that anxious depression-when defined either syndromally or dimensionally-has distinct neurobiological findings that separate it from nonanxious depression. Structural neuroimaging, EEG, genetics, and neuropsychiatric studies revealed differences in subjects with anxious depression compared to other groups. Endocrine differences between individuals with anxious depression and those with nonanxious depression have also been noted, as evidenced by abnormal responses elicited by exogenous stimulation of the system. Despite these findings, heterogeneity in the definition of anxious depression complicates the results. Because exploring the neurobiology of this depressive subtype is important for improving diagnosis, prognosis, and treatment, enrichment strategies to decrease heterogeneity within the field should be employed for future research.

Resting-state functional connectivity abnormalities in limbic and salience networks in social anxiety disorder without comorbidity

The neurobiology of social anxiety disorder (SAD) is not yet fully understood. Structural and functional neuroimaging studies in SAD have identified abnormalities in various brain areas, particularly the amygdala and elements of the salience network. This study is the first to examine resting-state functional brain connectivity in a drug-naive sample of SAD patients without psychiatric comorbidity and healthy controls, using seed regions of interest in bilateral amygdala, in bilateral dorsal anterior cingulate cortex for the salience network, and in bilateral posterior cingulate cortex for the default mode network. Twelve drug-naive SAD patients and pair-wise matched healthy controls, all drawn from the Netherlands Study of Depression and Anxiety sample, underwent resting-state fMRI. Group differences were assessed with voxel-wise gray matter density as nuisance regressor. All results were cluster corrected for multiple comparisons (Z>2.3, p<.05). Relative to control subjects, drug-naive SAD patients demonstrated increased negative right amygdala connectivity with the left middle temporal gyrus, left supramarginal gyrus and left lateral occipital cortex. In the salience network patients showed increased positive bilateral dorsal anterior cingulate connectivity with the left precuneus and left lateral occipital cortex. Default mode network connectivity was not different between groups. These data demonstrate that drug-naive SAD patients without comorbidity show differences in functional connectivity of the amygdala, and of areas involved in self-awareness, some of which have not been implicated in SAD before.

Aberrant limbic and salience network resting-state functional connectivity in panic disorder without comorbidity

BACKGROUND

Panic disorder (PD) is a prevalent and debilitating disorder but its neurobiology is still poorly understood. We investigated resting-state functional connectivity (RSFC) in PD without comorbidity in three networks that have been linked to PD before. This could provide new insights in how functional integration of brain regions involved in fear and panic might relate to the symptomatology of PD.

METHODS

Eleven PD patients without comorbidity and eleven pair-wise matched healthy controls underwent resting-state fMRI. We used seed regions-of-interest in the bilateral amygdala (limbic network), the bilateral dorsal anterior cingulate cortex (dACC) (salience network), and the bilateral posterior cingulate cortex (default mode network). RSFC of these areas was assessed using seed-based correlations. All results were cluster corrected for multiple comparisons (Z>2.3, p<.05).

RESULTS

Abnormalities were identified in the limbic network with increased RSFC between the right amygdala and the bilateral precuneus in PD patients. In the salience network the dACC demonstrated altered connectivity with frontal, parietal and occipital areas.

LIMITATIONS

The small sample size and hypothesis-driven approach could restrict finding additional group differences that may exist. Other caveats are reflected in the use of medication by two participants and the acquisition of the resting-state scan at the end of a fixed imaging protocol.

CONCLUSION

We found altered RSFC in PD between areas involved in emotion regulation and emotional and somatosensory stimulus processing, as well as an area engaged in self-referential processing, not implicated in models for PD before. These findings extend existing functional neuroanatomical models of PD, as the altered RSFC may underlie increased sensitivity for bodily symptoms.

Associations of current and remitted major depressive disorder with brain atrophy: the AGES-Reykjavik Study

BACKGROUND

To examine whether lifetime DSM-IV diagnosis of major depressive disorder (MDD), including age at onset and number of episodes, is associated with brain atrophy in older persons without dementia.

METHOD

Within the population-based Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study, 4354 persons (mean age 76 ± 5 years, 58% women) without dementia had a 1.5-T brain magnetic resonance imaging (MRI) scan. Automated brain segmentation total and regional brain volumes were calculated. History of MDD, including age at onset and number of episodes, and MDD in the past 2 weeks was diagnosed according to DSM-IV criteria using the Mini-International Neuropsychiatric Interview (MINI).

RESULTS

Of the total sample, 4.5% reported a lifetime history of MDD; 1.5% had a current diagnosis of MDD (including 75% with a prior history of depression) and 3.0% had a past but no current diagnosis (remission). After adjusting for multiple covariates, compared to participants never depressed, those with current MDD (irrespective of past) had more global brain atrophy [B = -1.25%, 95% confidence interval (CI) -2.05 to -0.44], including more gray- and white-matter atrophy in most lobes, and also more atrophy of the hippocampus and thalamus. Participants with current, first-onset MDD also had more brain atrophy (B = -1.62%, 95% CI -3.30 to 0.05) whereas those remitted did not (B = 0.06%, 95% CI -0.54 to 0.66).

CONCLUSIONS

In older persons without dementia, current MDD, irrespective of prior history, but not remitted MDD was associated with widespread gray- and white-matter brain atrophy. Prospective studies should examine whether MDD is a consequence of, or contributes to, brain volume loss and development of dementia.