Meta-analysis of cognitive function in Chinese first-episode schizophrenia: MATRICS Consensus Cognitive Battery (MCCB) profile of impairment

BACKGROUND: Compromised neurocognition is a core feature of schizophrenia. With increasing studies researching cognitive function of Chinese patients with first-episode schizophrenia (FES) using MATRICS Consensus Cognitive Battery (MCCB), it is not clear about the level and pattern of cognitive impairment among this population. AIM: To provide a meta-analysis systematically analysing studies of neurocognitive function using MCCB in Chinese patients with FES. METHODS: An independent literature search of both Chinese and English databases up to 13 March 2019 was conducted by two reviewers. Standardised mean difference (SMD) was calculated using the random effects model to evaluate the effect size. RESULTS: 56 studies (FES=3167, healthy controls (HC)=3017) were included and analysed. No study was rated as ‘high quality’ according to Strengthening the Reporting of Observational Studies in Epidemiology. Compared with HCs, Chinese patients with FES showed impairment with large effect size in overall cognition (SMD=−1.60, 95% CI −1.82 to −1.38, I(2)=67%) and all seven cognitive domains, with the SMD ranging from −0.87 to −1.41. In nine MCCB subtests, patients with FES showed significant difference in Symbol Coding (SMD=−1.90), Trail Making Test (TMT) (SMD=−1.36), Continuous Performance Test-Identical Pairs (SMD=−1.33), Hopkins Verbal Learning Test (SMD=−1.24), Brief Visuospatial Memory Test (SMD=−1.18), Mazes (SMD=−1.16), Category Fluency (SMD=−1.01), Spatial Span (SMD=−0.69) and Mayer-Salovey-Caruso Emotional Intelligence Test (SMD=−0.38). CONCLUSIONS: Our meta-analysis demonstrates that Chinese patients with FES show neurocognitive deficits across all seven MCCB cognitive domains and all nine subtests, particularly in two neurocognitive domains: speed of processing and attention/vigilance, with the least impairment shown in social cognition. Symbol Coding and TMT may be the most sensitive tests to detect cognitive deficit in Chinese patients with FES.