Brain-based classification of youth with anxiety disorders: transdiagnostic examinations within the ENIGMA-Anxiety database using machine learning

Neuroanatomical findings on youth anxiety disorders are notoriously difficult to replicate, small in effect size and have limited clinical relevance. These concerns have prompted a paradigm shift toward highly powered (that is, big data) individual-level inferences, which are data driven, transdiagnostic and neurobiologically informed. Here we built and validated supervised neuroanatomical machine learning models for individual-level inferences, using a case–control design and the largest known neuroimaging database on youth anxiety disorders: the ENIGMA-Anxiety Consortium (N = 3,343; age = 10–25 years; global sites = 32). Modest, yet robust, brain-based classifications were achieved for specific anxiety disorders (panic disorder), but also transdiagnostically for all anxiety disorders when patients were subgrouped according to their sex, medication status and symptom severity (area under the receiver operating characteristic curve, 0.59–0.63). Classifications were driven by neuroanatomical features (cortical thickness, cortical surface area and subcortical volumes) in fronto-striato-limbic and temporoparietal regions. This benchmark study within a large, heterogeneous and multisite sample of youth with anxiety disorders reveals that only modest classification performances can be realistically achieved with machine learning using neuroanatomical data.NWORubicon 019.201SG.022Advanced Behavioural Research MethodsHealth and Well-bein

Experimental Conditions For Stress Relaxation Test Of Orthodontic Elastomeric Chains

Background. Severe stress in social situations is a core symptom of social anxiety disorder (SAD). Connectivity between the amygdala and cortical regions is thought to be important for emotion regulation, a function that is compromised in SAD. However, it has never been tested if and how this connectivity pattern changes under conditions of stress-inducing social evaluative threat. Here we investigate changes in cortical-amygdala coupling in SAD during the anticipation of giving a public speech. Method. Twenty individuals with SAD and age-, gender-and education-matched controls (n = 20) participated in this study. During the functional magnetic resonance imaging (fMRI) session, participants underwent three 'resting-state' fMRI scans: one before, one during, and one after the anticipation of giving a public speech. Functional connectivity between cortical emotion regulation regions and the amygdala was investigated. Results. Compared to controls, SAD participants showed reduced functional integration between cortical emotion regulation regions and the amygdala during the public speech anticipation. Moreover, in SAD participants cortical-amygdala connectivity changes correlated with social anxiety symptom severity. Conclusions. The distinctive pattern of cortical-amygdala connectivity suggests less effective cortical-subcortical communication during social stress-provoking situations in SAD

Functional ecological genomics to demonstrate general and specific responses to abiotic stress.

1. Stress is a major component of natural selection in soil ecosystems. The most prominent abiotic stress factors in the field are temperature extremes (heat, cold), dehydration (drought), high salinity and specific toxic compounds such as heavy metals. Organisms are able to deal with these stresses to a certain extent, which determines the limits of their ecological amplitudes. Functional genomic tools are now becoming available to study stress in ecologically relevant soil organisms. 2. Here we give an overview of transcriptomic studies aiming to elucidate how plants and soil invertebrates respond and adapt to a stressful environment. The picture emerging from signalling pathways and transcription factors identified in transcription profiling studies suggests that there is a large overlap of genomic responses to drought, salinity and cold; however, heat and heavy metals trigger different stress response pathways. 3. The heat shock response and the oxidative stress response seem to represent universal components of the environmental stress response (ESR). Furthermore, the commonality across plants and animals seems to be higher in effector genes than in transcriptional regulators. 4. Finally, adaptation to stress factors in soil seems to evolve through enhanced constitutive transcription of otherwise stress responsive genes both in plants and animal