Background and objective: Olfactory disorders in COVID-19 impact quality of life and may lead to psychological impairments. Prevalence ranges from 8 to 85%, persisting in about 30% of cases. This study aimed to evaluate the 6-month post-COVID-19 impact on quality of life, hedonic experiences, anxiety and depression due to olfactory disorders. Additionally, it sought to compare psychophysical tests and self-perceived olfactory evaluations.
Methods: A prospective, longitudinal study was conducted over baseline (T0) and 6 months (T1) on individuals with persistent olfactory disorders post-COVID-19 for more than 6 weeks. Psychophysical tests employed the Sniffin' Sticks Test® (TDI score), and self-perceived olfactory evaluation used a Visual Analogue Scale. Quality of life was assessed with an Olfactive Disorder Questionnaire and the French version of the Quality of Life and Diet Questionnaire. Hedonic experiences were gauged using the Snaith-Hamilton Pleasure Scale, while anxiety and depression dimensions were measured by The State-Trait Anxiety Inventory, The Post Traumatic Stress Checklist Scale, and Hamilton Rating Scale for Depression. Participants were classified into the "normosmic group" (NG) and the "olfactory disorders group" (ODG) at T0 and T1 based on the TDI score.
Results: Were included 56 participants (58.93% women, 41.07% men) with a mean age of 39.04 years and a mean duration of post-COVID-19 olfactory disorders of 5.32 months. At T1, ODG had a significantly lower quality of life and hedonic experiences than NG. No significant differences in anxiety and depression dimensions were observed between groups. At T0, psychophysical tests and self-perceived olfactory evaluations were significantly correlated with quality of life and hedonic experiences in both groups. At T1, self-perceived olfactory evaluation in NG correlated significantly with quality of life, hedonic experiences, anxiety and depression dimensions, whereas ODG only correlated with hedonic experiences.
Conclusion: Individuals with persistent post-COVID-19 olfactory disorders after six months demonstrated compromised quality of life and hedonic experiences. Self-perceived olfactory evaluation played a more significant role in influencing quality of life and the dimension of anxiety and depression than the psychophysical presence of olfactory disorders. These findings emphasize the importance of considering patients' perceptions to comprehensively assess the impact of olfactory disorders on their well-being.
Trial registration: ClinicalTrials.gov number (ID: NCT04799977).
Keywords: Cognition; Covid-19; Emotion; Hedonic experiences (8 words); Odor perception; Olfactory disorders; Psychiatric; Psychopathology.
© 2024. The Author(s).