This study aimed to investigate the anxiety, depression, and psychological impact levels among people with and without psychiatric disease diagnosis in the quarantine and social isolation periods of the 2019 coronavirus disease (COVID-19) pandemic. This study using the case-control research technique, included 182 cases with psychiatric diagnosis and 183 control participants without a psychiatric diagnosis. The research used the Hamilton Anxiety Rating Scale (HAM-A), Hamilton Depression Rating Scale (HAM-D), Impact of Event Scale-Revised (IES-R), and a data form inquiring about sociodemographic characteristics. Data were collected from participants during face-to-face psychiatric interviews. The anxiety levels (OR: 6), depression levels (OR: 3.8), and psychological impact levels (OR: 5.8) were identified to be higher in the case group compared to the control group (p<0.05). The HAM-A, HAM-D, and IES-R scores were not affected by age, sex, marital status, education, place of residence, and employment status in the study group. Living alone, receiving treatment, presence of chronic disease, poor income, and COVID (+) relatives affected scores. In this study, those with a psychiatric diagnosis were affected more by the COVID-19 pandemic compared to those without a diagnosis, while among those with a psychiatric diagnosis, those not receiving treatment were more affected than those using treatment.