Long-term benzodiazepine use is associated with poorer cognitive function in schizophrenia: Findings from the SALT-C cohort

Background The association between long-term use of benzodiazepines (BDZs) and cognitive function in patients with schizophrenia has not been fully characterized. This study aimed to investigate the relationship between long-term BDZs use and cognitive impairment in schizophrenia. Methods Data were derived from an observational study of treatment with atypical antipsychotics in Chinese patients with schizophrenia (SALT-C). Fifty-seven patients with long-term use of BDZs (≥ 60 days) were included, and 57 BDZs non-users were matched using propensity scores for age, sex, disease duration, and atypical antipsychotics received. Cognitive impairment was assessed using the Montreal Cognitive Assessment (MoCA); psychotic symptoms, illness severity, and psychosocial functioning were assessed with the Positive and Negative Syndrome Scale (PANSS), the Clinical Global Impression-Severity (CGI-S) scale, and the Personal and Social Performance (PSP) scale. Between-group comparisons were performed using independent-samples t-tests or Mann–Whitney U tests. Multivariate analysis was performed using binary logistic regression. Results The long-term BDZs user group showed a significantly lower total MoCA score [16.02 (6.69)] than the BDZs non-user group [19.33 (7.11)] (P = 0.012). No significant between-group differences were observed in total scores on the PANSS, CGI-S, or PSP (all P > 0.05). Long-term BDZs use was independently associated with cognitive impairment (OR = 7.728, P = 0.017), whereas years of education was negatively associated with cognitive impairment (OR = 0.740, P = 0.007). Conclusions Long-term BDZs use is associated with poorer cognitive performance in patients with schizophrenia, suggesting that cognitive function should be monitored during BDZs treatment in this population.