4 research outputs found
Recommended from our members
Using fMRI connectivity to define a treatment-resistant form of post-traumatic stress disorder.
A mechanistic understanding of the pathology of psychiatric disorders has been hampered by extensive heterogeneity in biology, symptoms, and behavior within diagnostic categories that are defined subjectively. We investigated whether leveraging individual differences in information-processing impairments in patients with post-traumatic stress disorder (PTSD) could reveal phenotypes within the disorder. We found that a subgroup of patients with PTSD from two independent cohorts displayed both aberrant functional connectivity within the ventral attention network (VAN) as revealed by functional magnetic resonance imaging (fMRI) neuroimaging and impaired verbal memory on a word list learning task. This combined phenotype was not associated with differences in symptoms or comorbidities, but nonetheless could be used to predict a poor response to psychotherapy, the best-validated treatment for PTSD. Using concurrent focal noninvasive transcranial magnetic stimulation and electroencephalography, we then identified alterations in neural signal flow in the VAN that were evoked by direct stimulation of that network. These alterations were associated with individual differences in functional fMRI connectivity within the VAN. Our findings define specific neurobiological mechanisms in a subgroup of patients with PTSD that could contribute to the poor response to psychotherapy.PEV was supported by the Medical Research Council (grant no. MR/K020706/1) and is a Fellow of MQ: Transforming Mental Health (MQF17_24)
Identification of a Common Neurobiological Substrate for Mental Illness
Importance Psychiatric diagnoses are currently distinguished based on sets of specific symptoms. However, genetic and clinical analyses find similarities across a wide variety of diagnoses, suggesting that a common neurobiological substrate may exist across mental illness.Objective To conduct a meta-analysis of structural neuroimaging studies across multiple psychiatric diagnoses, followed by parallel analyses of 3 large-scale healthy participant data sets to help interpret structural findings in the meta-analysis.Data Sources PubMed was searched to identify voxel-based morphometry studies through July 2012 comparing psychiatric patients to healthy control individuals for the meta-analysis. The 3 parallel healthy participant data sets included resting-state functional magnetic resonance imaging, a database of activation foci across thousands of neuroimaging experiments, and a data set with structural imaging and cognitive task performance data.Data Extraction and Synthesis Studies were included in the meta-analysis if they reported voxel-based morphometry differences between patients with an Axis I diagnosis and control individuals in stereotactic coordinates across the whole brain, did not present predominantly in childhood, and had at least 10 studies contributing to that diagnosis (or across closely related diagnoses). The meta-analysis was conducted on peak voxel coordinates using an activation likelihood estimation approach.Main Outcomes and Measures We tested for areas of common gray matter volume increase or decrease across Axis I diagnoses, as well as areas differing between diagnoses. Follow-up analyses on other healthy participant data sets tested connectivity related to regions arising from the meta-analysis and the relationship of gray matter volume to cognition.Results Based on the voxel-based morphometry meta-analysis of 193 studies comprising 15 892 individuals across 6 diverse diagnostic groups (schizophrenia, bipolar disorder, depression, addiction, obsessive-compulsive disorder, and anxiety), we found that gray matter loss converged across diagnoses in 3 regions: the dorsal anterior cingulate, right insula, and left insula. By contrast, there were few diagnosis-specific effects, distinguishing only schizophrenia and depression from other diagnoses. In the parallel follow-up analyses of the 3 independent healthy participant data sets, we found that the common gray matter loss regions formed a tightly interconnected network during tasks and at resting and that lower gray matter in this network was associated with poor executive functioning.Conclusions and Revelance We identified a concordance across psychiatric diagnoses in terms of integrity of an anterior insula/dorsal anterior cingulate–based network, which may relate to executive function deficits observed across diagnoses. This concordance provides an organizing model that emphasizes the importance of shared neural substrates across psychopathology, despite likely diverse etiologies, which is currently not an explicit component of psychiatric nosology
Recommended from our members
Promoting learning health system feedback loops: Experience with a VA practice-based research network card study
BackgroundWe tested the capacity of the 60-site VA Women's Health Practice-Based Research Network (WH-PBRN), embedded within VA, to employ a multisite card study to collect women Veterans' perspectives about Complementary and Integrative Health (CIH) and to rapidly return findings to participating sites and partnered national policy-makers in support of a Learning Health System (LHS) wherein evidence generation informs ongoing improvement.MethodsVA primary care clinic clerks and nurses distributed anonymous surveys (patient feedback forms) at clinics for up to two weeks in fiscal year 2017, asking about CIH behavior and preferred delivery methods. We examined the project's feasibility, representativeness, acceptability, and impact via a tracking system, national administrative data, debriefing notes, and three surveys of WH-PBRN Site Leads.ResultsTwenty geographically diverse and largely representative VA Medical Centers and 11 Community-Based Outpatient Clinics volunteered to participate. Over six months, N = 1191 women Veterans responded (median 57; range 8-151 per site). In under three months, we returned local findings benchmarked against multisite findings to all participating sites and summary findings to national VA partners. Sites and partners disseminated results to clinical and leadership stakeholders, who then applied results as warranted.ConclusionsVA effectively mobilized an embedded PBRN to implement a timely, representative, acceptable and impactful operations project.ImplicationsCard studies by PBRNs within large, national healthcare systems can provide rapid feedback to participating sites and national leaders to guide policies, programs, and practices.Level of evidenceSelf-selected respondents could have biased results