Cortical and subcortical brain structure in generalized anxiety disorder: findings from 28 research sites in the ENIGMA-Anxiety Working Group.

The goal of this study was to compare brain structure between individuals with generalized anxiety disorder (GAD) and healthy controls. Previous studies have generated inconsistent findings, possibly due to small sample sizes, or clinical/analytic heterogeneity. To address these concerns, we combined data from 28 research sites worldwide through the ENIGMA-Anxiety Working Group, using a single, pre-registered mega-analysis.

Cingulate Cortex Structural Alterations in Substance Use Disorder Psychiatric Inpatients.

Background And Objectives: Substance use disorder (SUD) includes maladaptive patterns of substance use despite negative consequences. Previous structural neuroimaging studies showed some structural alterations in SUD, but it remains unknown whether these alterations are specifically associated with SUD or common comorbidities. This study attempts to validate the findings of structural differences between SUD, healthy controls (HC), and psychiatric controls (PC).

Subcortical brain morphometry of avoidant personality disorder.

Background: Avoidant personality disorder (AvPD) is a condition typified by social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluation. AvPD has a high comorbidity rate with other personality disorders and other psychological diagnostic categories. There is very little research investigating subcortical volumetry in AvPD.

Mega-analysis methods in ENIGMA: The experience of the generalized anxiety disorder working group.

The ENIGMA group on Generalized Anxiety Disorder (ENIGMA-Anxiety/GAD) is part of a broader effort to investigate anxiety disorders using imaging and genetic data across multiple sites worldwide. The group is actively conducting a mega-analysis of a large number of brain structural scans. In this process, the group was confronted with many methodological challenges related to study planning and implementation, between-country transfer of subject-level data, quality control of a considerable amount of imaging data, and choices related to statistical methods and efficient use of resources.

Hippocampal Volume in Psychiatric Diagnoses: Should Psychiatry Biomarker Research Account for Comorbidities?

Background: Many research papers claim that patients with specific psychiatric disorders (major depressive disorder, posttraumatic stress disorder, borderline personality disorder, alcohol use disorder, and others) have smaller hippocampi, but most of those reports compared patients to healthy controls. We hypothesized that if psychiatrically matched controls (psychiatric control, matched for demographics and psychiatric comorbidities) were used, much of the biomarker literature in psychiatric research would not replicate. We used hippocampus and amygdala volume only as examples, as these are very commonly replicated results in psychiatry biomarker research.

Orbitofrontal, dorsal striatum, and habenula functional connectivity in psychiatric patients with substance use problems.

Substance abuse is commonly defined as the persistence of drug use despite negative consequences. Recent preclinical work has shown that higher input from the orbitofrontal cortex (OFC) to the dorsal striatum was associated with compulsive reward-seeking behavior despite negative effects. It remains unknown whether drug use is associated with the connectivity between the OFC and dorsal striatum in humans.

Process genes list: An approach to link genetics and human brain imaging.

Background: Linking human genetics and brain imaging data is extremely challenging, among other reasons because both fields suffer from multiple comparison problems.

New Method: ProcessGeneLists (PGL) links genetics and human brain imaging by using genes associated with a disease and calculating a normalized mRNA expression average of those genes in each brain region. Brain regions in which those genes are most co-expressed become regions of interest (ROIs) to perform brain imaging in participants with and without the disease, decreasing multiple comparisons.

Right temporal pole volume reduction in PTSD.

Previous magnetic resonance imaging studies of post-traumatic stress disorder (PTSD) have reported cortical volume alterations in the parahippocampal, anterior cingulate cortex, and temporal pole. It is unclear, however, if these cortical regions are specifically associated with PTSD or associated with common comorbidities. Here, we present the result of cortical volume differences between PTSD and healthy and psychiatric controls.

Altered habenula resting state functional connectivity in deprived veteran tobacco smokers: A pilot study.

This study aimed to examine habenular resting state functional connectivity (RSFC) abnormalities in tobacco-smoking veterans. The authors explored RSFC in sated smokers (n = 3D 18), overnight deprived smokers (n = 3D 13), and nonsmoker controls (n = 3D 26). Seed-to-voxel analysis was used to explore RSFC in the habenula.

Insular resting state functional connectivity is associated with gut microbiota diversity.

The gut microbiota has recently gained attention as a possible modulator of brain activity. A number of reports suggest that the microbiota may be associated with neuropsychiatric conditions such as major depressive disorder, autism and anxiety. The gut microbiota is thought to influence the brain via vagus nerve signalling, among other possible mechanisms.

Habenular connectivity may predict treatment response in depressed psychiatric inpatients.

Introduction: The habenula (Hb) is a small midbrain structure that signals negative events and may play a major role in the etiology of psychiatric disorders including depression. The lateral Hb has three major efferent connections: serotonergic raphe nuclei, noradrenergic locus coeruleus, and dopaminergic ventral tegmental area/substantia nigra compacta. We wanted to test whether Hb connectivity may be important to predict treatment outcomes in depression patients.