The crossroads of anxiety: distinct neurophysiological maps for different symptomatic groups

Abstract

BackgroundDespite the devastating impact of anxiety disorders (ADs) worldwide, long-lasting debates on causes and remedies have not solved the clinician’s puzzle: who should be treated and how? Psychiatric classifications conceptualize ADs as distinct entities, with strong support from neuroscience fields. Yet, comorbidity and pharmacological response suggest a single “serotonin dysfunction” dimension. Whether AD is one or several disorders goes beyond academic quarrels, and the distinction has therapeutic relevance. Addressing the underlying dysfunctions should improve treatment response. By its own nature, neurophysiology can be the best tool to address dysfunctional processes.PurposeTo search for neurophysiological dysfunctions and differences among panic disorder (PD), agoraphobia-social-specific phobia, obsessive–compulsive disorder (OCD) and generalized anxiety disorder.MethodsA sample population of 192 unmedicated patients and 30 aged-matched controls partook in this study. Hypothesis-related neurophysiological variables were combined into ten independent factors: 1) dysrhythmic patterns, 2) delta, 3) theta, 4) alpha, 5) beta (whole-head absolute power z-scores), 6) event-related potential (ERP) combined latency, 7) ERP combined amplitude (z-scores), 8) magnitude, 9) site, and 10) site of hyperactive networks. Combining single variables into representative factors was necessary because, as in all real-life phenomena, the complexity of interactive processes cannot be addressed through single variables and the multiplicity of potentially implicated variables would demand an extremely large sample size for statistical analysis.ResultsThe nonparametric analysis correctly classified 81% of the sample. Dysrhythmic patterns, decreased delta, and increased beta differentiated AD from controls. Shorter ERP latencies were found in several individual patients, mostly from the OCD group. Hyperactivities were found at the right frontorbital-striatal network in OCD and at the panic circuit in PD.ConclusionsOur findings support diffuse cortical instability in AD in general, with individual differences in information processing deficits and regional hyperactivities in OCD and PD. Study limitations and the rationale behind the variable selection and combination strategy will be discussed before addressing the therapeutic implications of our findings.

Transdiagnostic Symptom Clusters and Associations With Brain, Behavior, and Daily Function in Mood, Anxiety, and Trauma Disorders

“…67,68 The frontal β elevation observed for anhedonia is somewhat surprising, because β waves are often associated with active or anxious thinking. 69,70 However, at least 1 previous study has shown a connection between increased β and depression specifically. 71 A possible account of the elevated parietal β and somewhat poor working memory of people with general anxiety is a parietally mediated compensation for core working memory dysfunction 72 ; however, in this study, the difference on working performance from other subtypes was not significant.…”

Lexical Disambiguation in Verb Learning: Evidence from the Conjoined-Subject Intransitive Frame in English and Mandarin Chinese

“…The intransitive frame may be underinformative in at least two ways. First, it is compatible with two different construals, arising from the fact that a DP denoting a plurality occupies the subject position (e.g., Scha, 1981 ; Gillon, 1987 ; Landman, 1989a , b ; Link, 1991 ; Verkuyl and van der Does, 1991 ). Under one interpretation of the conjoined subject, the collective interpretation, the property is predicated of the entire group (or sum) of participants, and there is one single, atomic event to which the verb refers, in which each member of the plurality is a participant.…”

Resting-state theta band connectivity and graph analysis in generalized social anxiety disorder

“…Evidence of alterations in resting-state theta band regional power have been reported in gSAD studies (Gerez et al, 2016, Sachs et al, 2004) and anomalous theta power or network connectivity has been shown in other disorders like depression (Leuchter et al, 2012b), obsessive-compulsive disorder (Koprivova et al, 2011), and post-traumatic stress disorder (Imperatori et al, 2014). Thus, our results are in line with above-mentioned reports of theta oscillation involvement internalizing conditions.…”