The effect of cognitive impairment based on Mini-Mental State Examination (MMSE) on suicidal tendency in patients with schizophrenia: A large cross-sectional study

The effect of cognitive function on suicidal tendency in patients with schizophrenia is still inconclusive. This study aimed to explore the effect of cognitive impairment on suicidal tendency in schizophrenia patients and the risk factors of suicidal tendency in schizophrenia patients with cognitive impairment. A total of 988 subjects were recruited for this study and finally 517 patients were included in the statistical analysis. Sociodemographic information was collected for each subject. Mini-Mental State Examination (MMSE) was used to assess patients' cognitive functioning. In addition, the Positive and Negative Syndrome Scale (PANSS) positive subscale, Insomnia Severity Index (ISI), and Beck Scale for Suicide Ideation (BSI) were used to assess psychotic symptoms, severity of insomnia, and intensity of suicidal ideation, respectively. Schizophrenia patients with cognitive dysfunction were significantly less likely to develop suicidal tendencies than those without cognitive dysfunction (P < 0.05, OR = 0.58, 95%CI: 0.39–0.81). In patients with cognitive impairment, those with suicidal tendency had substantially higher scores on BSI, ISI, EC, PD, IRI, F1, and PANSS positive subscale, and took more types of antipsychotic drugs than those without suicidal tendency (all P < 0.05), and the results of binary logistic regression analysis showed that, PANSS positive subscale score (B = 0.06, p = 0.04, OR = 1.07, 95%CI: 1.00–1.13) was a risk factor for suicidal tendencies. Our findings suggest that schizophrenia patients with cognitive dysfunction are significantly less likely to develop suicidal tendencies. Moreover, positive symptom is a risk factor for suicidal tendencies in schizophrenia patients with cognitive dysfunction.