Effects of Beliefs, Conspiracy Theories, and Vaccine Hesitancy on the Vaccination Status of Patients with Severe Mental Illness in a Tertiary Psychiatric Care Hospital in Türkiye

Background: The aim of the study was to investigate the relationship between the vaccination rates and vaccine hesitancy and the adoption of conspiracy theories by patients with severe mental illness in Turkiye.Methods: Ninety-eight outpatients with schizophrenia and 105 outpatients with bipolar disorder were included. A sociodemographical data form, a survey on beliefs and conspiracy theories on vaccines and Vaccine Hesitancy Scale were obtained. Vaccinated and unvaccinated groups were compared and evaluated separately for patients with schizophrenia and bipolar disorder. Results: Sixty-one (62.24%) patients in the schizophrenia group and 86 (81.90%) patients in the bipolar disorder group were vaccinated, and the vaccination rate in the schizophrenia group was significantly lower (P = .002). There was no significant difference in terms of Vaccine Hesitancy Scale scores or adoption of any particular conspiracy theory between patients with schizophrenia and bipolar groups. However, vaccinated and unvaccinated patients of schizophrenia and bipolar disorder groups differed in terms of adopting beliefs and conspiracy theories on vaccines. Sixty-five (75.58%) of the vaccinated patients in the bipolar group agreed with the statement "vaccines are safe," while this rate was 8 (42.11%) in the unvaccinated patients (P = .004). In the schizophrenia group, however, the main difference between the vaccinated and unvaccinated patients was adopting the beliefs that "vaccines have serious side effects" and "vaccines may cause homosexuality" (P= .0341 and P= .003, respectively).Conclusion: The vaccination status of patients with schizophrenia might be under the stronger influence of conspiracy theories and specialized mental health interventions may be needed to ensure vaccination in patients with schizophrenia.