Staging model in psychiatry: Review of the evolution of electroencephalography abnormalities in major psychiatric disorders

Abstract

Aim Clinical staging in psychiatry aims to classify patients according to the severity of their symptoms, from stage 0 (increased risk, asymptomatic) to stage 4 (severe illness), enabling adapted treatment at each stage of the illness. The staging model would gain specificity if one or more quantifiable biological markers could be identified. Several biomarkers reflecting possible causal mechanisms and/or consequences of the pathophysiology are candidates for integration into the clinical staging model of psychiatric illnesses. Methods This review covers the evolution (from stage 0 to stage 4) of the most important brain functioning impairments as measured with electroencephalography (EEG), in psychosis spectrum and in severe mood disorders. Results The present review of the literature demonstrates that it is currently not possible to draw any conclusion with regard to the state or trait character of any of the EEG impairments in both major depressive disorder and bipolar disorder. As for schizophrenia, the most promising markers of the stage of the illness are the pitch mismatch negativity as well as the p300 event‐related potentials, as these components seem to deteriorate with increasing severity of the illness. Conclusions Given the complexity of major psychiatric disorders, and that not a single impairment can be observed in all patients, future research should most likely consider combinations of markers in the quest for a better identification of the stages of the psychiatric illnesses.

Cortical Microcircuit Mechanisms of Mismatch Negativity and Its Underlying Subcomponents

“…MMN is an event-related potential (ERP) wherein a more negative scalp potential (occurring about 150 ms post-stimulus onset) is elicited by the ''deviant'' stimulus than by the ''redundant'' stimulus in an oddball paradigm (Figures 2A-C). Diminished or absent MMN is a classic, highly replicated biomarker for sensory context processing deficits common in schizophrenia (SZ) and other psychotic disorders (Näätänen et al, 2011(Näätänen et al, , 2014Lavoie et al, 2019;Tada et al, 2019), so efforts to describe the biological substrates and mechanisms of human MMN remain paramount. Indeed, some progress has been made to understand MMN generation (Garrido et al, 2009), but confoundingly, MMN comprises both SSA and DD ( Figure 2E).…”

Positive and negative syndrome scale in forensic patients with schizophrenia spectrum disorders: a systematic review and meta-analysis

“…Schizophrenia is a heterogeneous disorder characterized by a range of possible different symptoms, especially positive and negative symptoms, and their prevalence also depends on the disorder stage [ 60 ]. Schizophrenia can be staged as it develops [ 61 ]. Positive symptoms have been regarded as features of early and acute schizophrenia, with negative symptoms developing during later stages of the illness [ 62 ].…”

3 steps to bend the curve of schizophrenia

“…Similarly, LAIs are best used in Stage 1 schizophrenia, which is the first episode (schizophrenia researchers now regard the illness as having stages). 15 Unfortunately, it is now rare for patients with schizophrenia to be switched to LAI pharmacotherapy right after recovery from the FEP. Instead, LAIs are more commonly used in Stage 3 or Stage 4, when the brains of patients with chronic schizophrenia have been already structurally damaged, and functional disability had set in.…”