P50 inhibition deficit in patients with chronic schizophrenia: Relationship with cognitive impairment of MATRICS consensus cognitive battery

Objective: Cognitive impairment is a core symptom of schizophrenia (SCZ); however, its pathophysio-logical mechanisms remain unclear. The sensory gating (SG) deficits reflected by P50 inhibition are recurring in SCZ, and this inhibition may be related to the cognitive deficits seen in these individuals. This study aimed to investigate the relationship between P50 inhibition and cognitive dysfunction in SCZ, which has not been fully investigated up to this point. Methods: A total of 270 individuals with chronic SCZ and 116 healthy controls were enrolled in the study. Psychopathology of SCZ was rated by the positive and negative syndrome scale (PANSS), while cognitive function and P50 inhibition of subjects were assessed by the MATRICS Consensus Cognitive Battery (MCCB) and the electroencephalography system. Results: The MCCB total and its 10 index scores were significantly lower in patients than those in healthy controls (all p <0.001). SCZ patients had a lower amplitude of S1, and higher P50 ratio than healthy controls (both p <0.01). However, there were no significant correlations between the P50 ratio and any of the PANSS total and its subscale scores in SCZ patients (all p > 0.05). Moreover, no correlation was found between the P50 components and the MCCB scores (all p> 0.05). Conclusions: Our findings suggest that the P50 inhibition deficits occur in Chinese individuals with SCZ, which may not be associated with their clinical symptoms and cognitive impairment. (C) 2019 Elsevier B.V. All rights reserved.