Mismatch negativity and cognitive performance in the course of schizophrenia.

Background: Cognitive deficits and abnormal event-related brain potentials (ERP) have been proposed as risk markers for the development of schizophrenia. Evidence is inconclusive whether these markers indicate a risk for the development of psychosis or illness progression.

Methods: The present study aimed at further clarification by comparing symptom expression (Brief Psychiatric Rating Scale, BRPS), the ERP Mismatch Negativity (MMN), and neuropsychological performance on the MATRICS Consensus Cognitive Battery between healthy controls (HC, n = 38) and individuals at different stages of illness: individuals at risk for psychosis (ARP, n = 33), patients at first admission, thus, early stage (ES, n = 35), chronic schizophrenia patients (CS, n = 25).

Environmental adversities and psychotic symptoms: The impact of timing of trauma, abuse, and neglect.

Background: Trauma and adverse childhood experiences (ACE) occur more often in mental illness, including psychosis, than in the general population. Individuals with psychosis (cases) report a higher number and severity (dose) of adversities than healthy controls. While a dose-dependent increase of adversities has been related to more severe psychopathology, the role of type and timing is still insufficiently understood on the exacerbation of positive and negative psychotic symptoms.