Comparison of cognitive dysfunction between schizophrenia and bipolar disorder patients: A meta-analysis of comparative studies

• Published in: Journal of affective disorders 2020-09, Vol.274, p.652-661
• Main Authors: Li, Wen, Zhou, Fu-Chun, Zhang, Ling, Ng, Chee H., Ungvari, Gabor S., Li, Jun, Xiang, Yu-Tao
• Format: Article
• Language: English
• Subjects: Bipolar disorder; Bipolar Disorder - complications; Cognition; Cognitive Dysfunction - complications; Humans; MCCB; Meta-analysis; Neuropsychological Tests; Schizophrenia; Schizophrenia - complications
• ISSN: 0165-0327; 1573-2517
• DOI: 10.1016/j.jad.2020.04.051

•Comparisons of cognition between schizophrenia and bipolar disorder are mixed.•To avoid heterogeneity caused by instruments, only studies using MCCB were included.•Schizophrenia associated with more severe cognitive impairment than bipolar disorder.•Timely treatment of cognitive dysfunction should be delivered for schizophrenia. Cognitive dysfunction is common in both schizophrenia and bipolar disorder. This is a meta-analysis of studies that compared cognitive dysfunction between schizophrenia and bipolar disorder. Both international and Chinese databases were systematically searched. Studies that compared cognitive function between schizophrenia and bipolar disorder with the MATRICS Consensus Cognitive Battery (MCCB) were analyzed using the random-effects model. Twelve studies with 9,518 participants (4,411 schizophrenia and 5,107 bipolar patients) were included in the analyses. Schizophrenia patients performed significantly worse than bipolar patients on the MCCB total scores with a large effect size (SMD=-0.80, 95%CI: -1.21 to -0.39), as well as on all the 7 subscale scores; attention (SMD=-2.56, 95%CI: -3.55 to -1.57) and social cognition (SMD=-0.86, 95%CI: -1.13 to -0.58) with large effect sizes; and speed of processing (SMD=-0.75, 95%CI: -1.00 to -0.49), working memory (SMD=-0.68, 95%CI: -0.91 to -0.45), verbal learning (SMD=-0.78, 95%CI: -0.95 to -0.61), visual learning (SMD=-0.65, 95%CI: -0.83 to -0.48), and reasoning and problem solving (SMD=-0.61, 95%CI: -0.93 to -0.29) with medium effect sizes. Compared to bipolar patients, patients with schizophrenia had more severe cognitive dysfunction in this meta-analysis, particularly in attention and social cognition. Timely assessment and treatment of cognitive dysfunction should be part of standard management protocols in both schizophrenia and bipolar disorder.