Impact of COVID-19 on Psychiatric Patients: The Role of Vaccination, Comorbidities, and Biomarkers in Clinical Outcomes

<b>Background/Objectives</b>: The COVID-19 pandemic has posed significant challenges, particularly for individuals residing in psychiatric facilities. This study aims to investigate the impact of COVID-19 on psychiatric patients, focusing on factors such as their vaccination status, comorbidities, medication regimens, and biomarkers like C-reactive protein (CRP) and ferritin. <b>Methods</b>: This retrospective study analyzed 100 patients with confirmed SARS-CoV-2 infections admitted to the private psychiatric clinic "Asclepius of Upper Volos" from March 2020 to March 2023. The data collected included sociodemographic characteristics, vaccination status, symptom severity, medication regimens, and levels of CRP and ferritin. Statistical analyses using IBM SPSS Statistics version 29 included Pearson's chi-square tests, Student's t-tests, and a survival time analysis via the log-rank test to assess associations between clinical characteristics and outcomes. <b>Results</b>: Among the participants, 64% were female and 74% received two doses of the COVID-19 vaccine. The majority experienced mild symptoms, with a survival rate of 74%. Statistically significant findings include a higher survival rate among vaccinated individuals (98.6%) versus unvaccinated individuals (1.4%, <i>p</i> < 0.001). Comorbidities like chronic obstructive pulmonary disease (COPD), coronary artery disease, and renal failure were associated with severe symptoms and higher mortality rates. Higher ferritin levels were significantly associated with poorer outcomes, with survivors having a mean ferritin level of 246.2 (SD = 150.3) compared to the 416.9 (SD = 215.9) seen in non-survivors (<i>p</i> < 0.001). Similarly, mean CRP levels were lower in survivors (1.58, SD = 1.96) than in non-survivors (3.46, SD = 2.92), with a <i>p</i>-value of 0.002. <b>Conclusions</b>: The findings underscore the importance of tailored health protocols and continued support for this vulnerable population. Enhanced strategies for managing comorbidities and utilizing biomarkers can aid in better predicting and improving psychiatric patient outcomes.