Psychological Impact and Clinical Correlates of Olfactory Dysfunction in Post- COVID-19 and Non-COVID-19 Patients: A Comparative Study

Abstract

Olfactory dysfunction (OD) has been reported in individuals who have recovered from COVID-19. Those with OD after COVID-19 (COVID-19 group) exhibited more severe psychiatric symptoms than those with OD from other etiologies (non-COVID-19 group). This study aimed to investigate the differences in psychological symptoms and related clinical factors between the two groups. Fifty-two participants (26 COVID-19 group; 26 non-COVID-19 group) were recruited. Both objective and subjective olfactory function were assessed. Symptoms of depression, anxiety, and perceived stress were measured using self-report scales. There were no significant differences in objective and subjective olfactory function or psychological symptoms between the groups, except for age and the short version of the Questionnaire of Olfactory Disorders-negative statements (sQOD-NS). The sQOD-NS score was negatively correlated with the duration of OD only in the COVID-19 group. Both groups showed significant correlations between the sQOD-NS and the Patient Health Questionnaire-9 (PHQ-9) scores. Mediation analysis showed that the duration of OD indirectly affected PHQ-9 scores via sQOD-NS in the entire sample and particularly in the COVID-19 group. The findings suggest that subjective distress from OD may mediate the relationship between duration of OD and depressive symptoms in COVID-19 patients, highlighting the need for targeted psychiatric interventions after COVID-19.