Dysfunction of Cognition Patterns Measured by MATRICS Consensus Cognitive Battery (MCCB) among First Episode Schizophrenia Patients and Their Biological Parents.

Background: Schizophrenia is characterized by abnormal perception, thinking, emotions, and behaviors. Cognitive dysfunction is acknowledged as one of the most pivotal symptoms in schizophrenia. In addition to positive or negative symptoms, which had been proposed by Gallhofer in the early 1970s, schizophrenia patients suffered from cognitive impairments as well. Many studies show that there is genetic susceptibility in the first grading kinship of patients with schizophrenia. Patients with schizophrenia have cognitive impairment not only in the acute phase but also in the stable phase. Studies also show that the healthy first-grading relatives of patients with schizophrenia suffer from cognitive defects. However, there is still a lack of studies about the cognitive features of biological parents of those with schizophrenia. In this study, we speculate the biological parents of schizophrenia patients have specific cognitive dysfunction. And we explore the patterns of cognition among both schizophrenia patients and their biological parents using the Chinese version of MATRICS Consensus Cognitive Battery (MCCB).

Aims: Cognitive features of patients with schizophrenia might be affected by the cognition mode of patients' biological parents. The dysfunctional cognitive patterns need to be characterized among the patients with schizophrenia and their parents.

Methods: We applied the MATRICS Consensus Cognitive Battery (MCCB, a novel measurement tool) to evaluate the cognitive function of 29 first-episode patients with schizophrenia (meeting ICD-10 diagnostic criteria for schizophrenia, aged between 17-45 years old), 58 cases of biological parents of schizophrenia patients (aged between 40-70 years old) and 46 healthy controls (aged between 40-70 years old). Furthermore, we explored the relationship between the cognitive dysfunction in patients with schizophrenia and their biological parents. All data were analyzed using SPSS18.0 statistical software.

Results: 1) Male patients with schizophrenia had obvious cognitive defects in six domains of cognitive function as measured by the MCCB (all except the social cognition domain) compared to their male parents. Female patients showed lower ability on both working memory and problem reasoning than their female parents. 2) The significant differences of both working memory and reasoning problems also existed between the patients' fathers and matched healthy controls. 3) Patients' mothers didn't show any significant difference on the problem reasoning domain compared with healthy controls. However, the visual learning domain appeared abnormal in patients' mothers compared with healthy controls.

Conclusion: There are six dimensions of cognitive impairments in both first-episode schizophrenia patients and their biological parents. Compared with healthy controls, patients' biological parents have conspicuous dysfunction in domains of working memory, problem reasoning and visual learning as well. Further study is needed to explore the underlying mechanisms of similar cognitive dysfunction between first-episode schizophrenia patients and their biological parents.