Sudden unexplained death in schizophrenia patients: An autopsy-based comparative study from China

Explainable sudden deaths in schizophrenia patients due to both cardiac (SCD) and non-cardiac causes (SNCD) have been extensively documented. However, sudden unexplained death (SUD) in this cohort remains to be elucidated. This study retrospectively analyzed 18 SUD cases that underwent systematic autopsy at our institutes during the period 2010-2022. The etiological, demographic, and autopsy features of the SUD cases were then compared with 37 year-matched sudden explainable deaths (23 SCD cases and 14 SNCD cases). Our results showed that the average age of the SUD was 39.0 ( ± 8.4) years, with the disease duration of 11.8 ( ± 8.1) years and a male/female ratio of 11:7. Most cases occurred during daytime (72.2%) and outside of hospital (77.8%). A large proportion of the SUD cases (77.8%) had persistent psychiatric episodes before death. Clozapine was found to be the most commonly used antipsychotic (33.3%), followed by Olanzapine (27.8%), Risperidone (27.8%) and Chlorpromazine (27.8%) in the SUD cases. When compared among groups, the SUD cases showed significantly younger ages (p = 0.035), lower heart weight (p = 0.004) and lower proportion of Clozapine use (p = 0.045). The presence of persistent psychiatric episodes was significantly higher in the SUD group than in any explainable deaths (p = 0.018) and was an independent risk factor for SUD (OR = 4.205, p = 0.040). This is the first autopsy-based study of SUD cases from China. We conclude that a stable mental state maintained by antipsychotics (i.e., Clozapine) is vital to schizophrenia patients.