Several Factors Predict COVID-19 Vaccine Hesitancy Among Psychiatric Patients

Severe mental illness, young age, lower education level, and lower socioeconomic status are among the most common risk factors for COVID-19 vaccination hesitancy among the psychiatric population, according to study findings published in Psychiatry Research Communications.

Researchers reviewed COVID-19 vaccination hesitancy studies in relation to psychiatric disorders in the PubMed, Medline, and Embase databases, and targeted studies that examined possible determinant factors. They included 15 studies (13 cross-sectional, 1 longitudinal cohort, 1 longitudinal online) conducted during the pandemic and published between January 2020 and August 2022.

Among the 15 studies, it was commonly observed that patients with mental illnesses had more vaccination hesitancy or lower vaccination rates, and patients with severe mental illness (including schizophrenia) were least accepting of the vaccination. This was attributed to disorder stigma, mental health, and impairment of decision-making skills. The researchers noted that higher level of education was associated with less vaccine hesitancy, and lower socioeconomic status was associated with increased vaccine hesitancy. Younger participants were also found to have a greater likelihood of vaccine hesitancy.

Sex was not a significant factor regarding vaccine hesitancy, and no significance was found between substance use disorders and vaccination hesitancy. Several of the reviewed studies noted a connection between vaccination hesitancy and anxiety disorders and PTSD.

It was noted that the association between vaccine hesitancy and most psychiatric conditions totally resolved with regression models for sociodemographic characteristics other than tobacco and substance use disorders. Possible causes for vaccination hesitancy were suggested to include vaccination priority controversy, stigma surrounding mental disorders, and lack of clearly defined vaccine guidelines for individuals with psychiatric disorders.

Hospitalized patients showed less hesitancy for vaccination than patients living in a community setting. One study contradicted the other 14 studies by finding that those patients with severe mental illness were willing to be vaccinated and their willingness was independent of clinical severity.

Limitations of the reviewed studies include nonresponse bias, social desirability bias, selection bias, low generalizability, underpowered sample size, and recall and reporting bias.

Researchers concluded, “[T]he following risk factors for COVID-19 vaccine hesitancy: diagnosis of severe mental illness such as schizophrenia (impaired decision making), lower socioeconomic status, lower educational level, and young age. As pathology severity increases, less awareness around the need for vaccination and misinformation endorsement could be considered an important determinant for vaccine hesitancy.”