High levels of anxiety and depression symptoms have been reported in patients with COVID-19 compared to the general population. These symptoms were related to variables such as gender, age, and education level with anxiety/depression levels. We aimed to determine the relationship between anxiety and depression symptoms and epidemic-related decreased functioning, worry, and quality of life (QoL). The study included 238 hospitalized participants due to COVID-19 and 168 participants who were hospitalized for reasons other than COVID-19. The Hospital Anxiety and Depression Scale (HADS), Short Form 36 (SF-36) QoL Scale, and questionnaires prepared by the researchers were applied. The effects of current worries, impairment in QoL, and decreased functioning during quarantine on levels of anxiety and depressive symptoms were investigated by implementing multiple linear regression analyzes. Our study results suggested the anxiety and depression levels of patients with COVID-19 were not higher than those in the internal medicine inpatient unit at the same time. Worries about transmission to others, uncertainty, social media news, and health anxiety increased the psychiatric symptoms of participants with COVID-19. Disruptions in social relationships and health also have an effect on anxiety/depression symptom levels. Conversely, results indicated losses and worries in occupation and finance did not significantly affect mental symptoms. Worries about transmission to others, uncertainty and health anxiety are closely related to anxiety and depression among patients with COVID-19. There is a need for research in the mental health field for the later stages of the pandemic in different cultures.