Sex differences in association between cognitive impairment and clinical correlates in Chinese patients with first-episode drug-naïve schizophrenia

Abstract

Background Schizophrenia is a complex mental illness with significant sex differences. Cognitive impairment is common in patients with schizophrenia, even in remission. This study was designed to examine the sex differences in the relationship between cognitive impairment and clinical correlations with first-episode drug-naïve (FEDN) schizophrenia. Methods 93 FEDN patients (male/female = 45/48) and 160 controls (male/female = 74/86) were enrolled to compare the sex differences in cognitive functions measure by the MATRICS Consensus Cognitive Battery (MCCB). Positive and Negative Syndrome Scale (PANSS) and Hamilton Depression Scale (HAMD) were used to evaluated patients' clinical symptoms. We compared cognitive impairment with sociodemographic characteristics and measures of different genders, as well as group-by-sex interactions. Results Our results showed that the MCCB total and index score in FEDN were lower than in the control group, except for category fluency and social cognition. Male patients had significantly lower symbol coding, digital sequence, and verbal learning scores than female patients, and the controls showed a similar sex difference. Interestingly, we also found six indexes and MCCB total score that showed diagnosis-by-sex interactions, belonging to the speed of processing, attention, working memory, and verbal learning. The MCCB total score showed correlations with PANSS total score and education for both genders. In female patients, education showed significant positive correlations with MCCB total and all ten index scores. Multiple linear regression analysis confirmed that negative symptoms and general psychopathology of PANSS, HAMD total score, and education were independent contributors to MCCB total score. In male patients, only education was an independent contributor to MCCB total score. Conclusions These findings revealed significant sex differences in cognitive impairments and clinical symptoms in FEDN. These results should be considered, which will be worthy of a follow-up study of schizophrenia in the future.

Sex differences between serum total bilirubin levels and cognition in patients with schizophrenia

“…Zhang et al found that male SCZ patients showed worse cognition than females in social cognition, processing speed, working memory, verbal learning and visual learning [ 25 ]. Other researchers had similar findings [ 26 – 28 ]. Moreover, sex differences in oxidative stress have been reported in numerous basic and clinical studies, wherein male SCZ patients exhibit higher oxidative stress than female SCZ patients [ 29 , 30 ].…”

Gender Differences in Clinical and Psychosocial Features Among Persons With Schizophrenia: A Mini Review

“…The review by Mendrek and Mancini-Marïe (8) highlighted that several studies found better neurocognitive functions in female than in male patients, while others found an opposite pattern or no gender difference. Findings of more recent studies did not clarify this picture, as a greater neurocognitive impairment has been reported in males (15,71,(80)(81)(82) but also in females (83), or no gender differences (67). Moreover, when gender differences were found, the patterns of impaired cognitive domains in males and females varied among studies.…”

“…Discrepancies in these findings may be due to the heterogeneity of clinical expression in schizophrenia (8), such as the presence/absence of severe negative symptoms in the clinical picture, as they have been found correlated to cognitive impairment in several studies (79,87). Also methodological factors such as differences in sample size or the heterogeneity of tests used to assess cognitive functions may account for discrepancies among studies; as a matter of fact, among the above reported studies, only three (80,82,83) assessed neurocognitive domains by means of the MATRICS Consensus Cognitive Battery, which is considered the gold standard to reliably assess neurocognitive functions in subjects with schizophrenia (88).…”