ABSTRACT
Several observational studies investigated the relationship between pre-diagnosis with mental disorders and COVID-19 outcomes. Thus, we have decided to conduct this meta-analysis to explore this relationship. We complied to the PRISMA guidelines in conducting this meta-analysis. PubMed, ScienceDirect, Google Scholar and medRxiv were searched until the 15th of February, 2021. We used the Random effect model in Meta XL, version 5.3 to pool the included studies. Statistical heterogeneity was assessed using Cochran's Q heterogeneity test and I². This meta-analysis included 634,338 COVID-19 patients from 16 studies. Our findings revealed that pre-diagnosis with mental disorders increased the risk of COVID-19 mortality and severity. This increase in the risk of COVID-19 mortality and severity remained significant in the model that only included the studies that adjusted for confounding variables. Furthermore, higher mortality was noticed in the included studies among schizophrenia, schizotypal and delusional disorders patients compared to mood disorders patients. In this meta-analysis we provided two models which both reported a significant increase in the risk of COVID-19 severity and mortality among patients with mental disorders, and with the upcoming COVID-19 vaccines, we recommend to give this category the priority in the vaccination campaigns along with medical health providers and elderly.