Lack of progressive reduction in P3 amplitude after the first-episode of schizophrenia: A 6-year follow-up study

P3 event-related potential may track the course of neurophysiological pathology in schizophrenia. Reduction in the amplitude of the auditory P3 is a widely replicated finding, already present at the first psychotic episode, in schizophrenia. Whether a progressive deficit is present in auditory P3 in schizophrenia over the course of illness is yet to be clarified. Previous longitudinal studies did not report any change in P3 over time in schizophrenia. However, these studies have been inconclusive, because of their relatively short follow-up periods, lack of follow-up data on controls, and assessment of patients already at the chronic stages of schizophrenia. Auditory P3 potentials, elicited by an oddball paradigm, were assessed in 14 patients with first-episode schizophrenia and 22 healthy controls at baseline and at the 6-year follow-up. P3 amplitudes were smaller in patients with first-episode schizophrenia than in controls. Importantly, over the 6-year interval, the P3 amplitudes were reduced in controls, but they did not change in patients. The lack of P3 reduction over time in patients with schizophrenia might be explained by the maximal reduction in P3 already at baseline or by the alleviation of P3 reduction over time. (C) 2016 Elsevier Ireland Ltd. All rights reserved

Novelty P3 and P3b in first-episode schizophrenia and chronic schizophrenia

The objective of this study was to evaluate P3b and novelty P3 responses in patients with first-episode schizophrenia (FES) and chronic schizophrenia (CS). P3b is consistently reported to be reduced in CS. However, novelty P3 results in CS are controversial. Novelty P3 is not studied, and there are only a few P3b studies in patients with FES. Subject groups comprised 31 patients with FES and 36 younger control subjects, and 26 patients with CS and 35 older control subjects. Automatically elicited auditory novelty P3 and effortfully elicited auditory P3b potentials were assessed. P3b amplitudes were reduced in both patients with FES and CS relative to their controls. CS and FES patients did not differ in P3b amplitude. Novelty P3 amplitude was reduced in patients with CS. Novelty P3 amplitude in patients with FES did not differ from their controls. P3b amplitude reduction may be a trait marker of schizophrenia and may not progress over the course of illness, although this can only be definitively determined by longitudinal studies. Novelty P3 amplitude reduction present in patients with CS, is not found at the onset of illness. Novelty P3 seems unaffected early in the disease process. (c) 2006 Elsevier Inc. All rights reserved

Relationship of negative symptom severity with cognitive symptoms and functioning in subjects at ultra-high risk for psychosis

Aim Negative symptoms and cognition are related with functioning in schizophrenia. However, it is not clear whether they have a similar effect in individuals at ultra-high risk (UHR) for psychosis. In this study, we aimed to explore relationship of negative symptoms with cognition and functioning cross-sectionally in people with UHR for psychosis. Methods In total, 107 people participated in this study. We assessed negative symptoms with Scale for Negative Symptoms (SANS). We applied a cognitive battery including seven tests. We evaluated functioning by using Global Assessment of Functioning Scale and work/study status as an indicator of role functioning. Results SANS scores were correlated to global functioning cross-sectionally. SANS total score was correlated to cognitive test scores related to cognitive flexibility and attention. Only Trail Making Test B (TMT B) was negatively correlated to global functioning. SANS-affective blunting and SANS-avolition scores were independently related to global functioning. There was a significant indirect effect of the TMT B and composite attention scores on global functioning through negative symptoms indicating a complete mediation. Conclusion Our findings suggest that negative symptoms, particularly avolition have an impact on functioning and the association of cognition with functioning was mediated by negative symptoms in UHR

Cognitive deficits in clinical and familial high risk groups for psychosis are common as in first episode schizophrenia

The aim of this sudy is to compare the neurocognitive functions in individuals with clinical or genetic risk for psychosis, in patients with first-episode schizophrenia (FES) and in healthy controls

Cognitive deficits in clinical and familial high risk groups for psychosis are common as in first episode schizophrenia

The aim of this sudy is to compare the neurocognitive functions in individuals with clinical or genetic risk for psychosis, in patients with first-episode schizophrenia (FES) and in healthy controls

N2 AND P3 POTENTIALS IN EARLY-ONSET AND LATE-ONSET PATIENTS WITH OBSESSIVE-COMPULSIVE DISORDER

Background: Impaired cognitive control processes may be central in the pathogenesis of obsessive-compulsive disorder (OCD). Our objective was to evaluate cognitive control processes with event-related potentials in early-onset OCD (EO) and late-onset OCD (LO), which are suggested to have distinct characteristics. Methods: Participants were unmedicated EO (n = 26) and LO patients (n = 33) without comorbid psychopathology and healthy controls (n = 54). Go/No-go tasks with 50 and 80% Go trial probabilities were implemented to manipulate the strength of response conflict and inhibitory demands. Results: LO patients had shorter N2 latencies than controls and did not show the N2 amplitude increase seen in controls with the increase in Go trial probability as suggestive of abnormal conflict monitoring processes. Both EO and LO patients showed smaller P3 increase than controls with the increase in Go trial probability, suggesting problems in modifying attentional control with changes in task demands. P3 was more anteriorly distributed in LO patients than controls. Additionally, P3 increase, with the increase in Go trial probability, was larger in frontal and central sites than in parietal sites in controls, whereas in EO patients it was almost homogenous across anteroposterior sites. Conclusions: N2 processes were affected only in LO, whereas P3 processes were affected in both EO and LO, although, somewhat differently. P3 distributions suggest that EO and LO patients have differences concerning the contributions of frontal and parietal components of attentional networks to the execution of Go/No-go tasks. Our results imply that EO and LO are distinct subtypes affecting the cognitive control systems differently. (C) 2013 Wiley Periodicals, Inc