Association between olfactory dysfunction and mood disturbances with objective and subjective cognitive deficits in long-COVID

Tania Llana; Marta Mendez; Sara Garces-Arilla; Vanesa Hidalgo; Magdalena Mendez-Lopez; M-Carmen Juan

doi:10.3389/fpsyg.2023.1076743

Association between olfactory dysfunction and mood disturbances with objective and subjective cognitive deficits in long-COVID

Front Psychol. 2023 Feb 2:14:1076743. doi: 10.3389/fpsyg.2023.1076743. eCollection 2023.

Authors

Tania Llana^{1

2

3

4}, Marta Mendez^{1

2

3}, Sara Garces-Arilla^{4

5}, Vanesa Hidalgo^{5

6}, Magdalena Mendez-Lopez^{5

7}, M-Carmen Juan⁴

Affiliations

¹ Department of Psychology, Faculty of Psychology, University of Oviedo, Oviedo, Spain.
² Neuroscience Institute of Princedom of Asturias (INEUROPA), Oviedo, Spain.
³ Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Av. del Hospital Universitario, Oviedo, Spain.
⁴ Instituto Universitario de Automática e Informática Industrial, Universitat Politècnica de València, Valencia, Spain.
⁵ Department of Psychology and Sociology, University of Zaragoza, Zaragoza, Spain.
⁶ Laboratory of Social Cognitive Neuroscience, Department of Psychobiology, University of Valencia, Valencia, Spain.
⁷ IIS Aragon, Zaragoza, Spain.

Abstract

Background and purpose: The coronavirus disease 2019 (COVID-19) has been associated with olfactory dysfunction. The persistent symptoms of anosmia or hyposmia were associated in previous studies with the development of memory impairment and mood disturbances. We aimed to investigate the association between the chronicity of reported olfactory dysfunction and subjective and objective cognitive performance in long-COVID patients and to explore whether their emotional symptoms are related to their cognition.

Methods: One hundred twenty-eight long-COVID participants were recruited. Reported symptomatology, subjective memory complaints, anxiety and depression symptomatology, and trait-anxiety were assessed. Subjective memory complaints and mood disturbances were compared among groups of participants with olfactory dysfunction as an acute (AOD), persistent (POD), or nonexistent (NOD) symptom. Seventy-six of the volunteers also participated in a face-to-face session to assess their objective performance on tests of general cognitive function and verbal declarative memory. Objective cognitive performance and mood disturbances were compared among the AOD, POD, and NOD groups.

Results: The subjective memory complaints and the anxiety and depression symptoms were similar among the groups, but the score in general cognitive function was lower in the participants with symptoms of acute olfactory dysfunction than in those with no olfactory symptoms at any time. Participants' memory complaints were positively related to their emotional symptoms. The relationship between depressive symptomatology and memory complaints interacted with the olfactory dysfunction, as it only occurred in the participants without symptoms of olfactory dysfunction. Depressive symptomatology and acute olfactory symptoms were negatively associated with general cognitive function and delayed memory performance. The months elapsed from diagnosis to assessment also predicted delayed memory performance. Anxious symptomatology was negatively associated with the immediate ability to recall verbal information in participants who did not present olfactory dysfunction in the acute phase of the infection.

Conclusion: Olfactory dysfunction in the acute phase of the infection by COVID-19 is related to cognitive deficits in objective tests, and mood disturbances are associated with self-reported and objective memory. These findings may contribute to further understanding the neuropsychological and emotional aspects of long-COVID.

Keywords: anxiety; cognition; depression; long-covid; memory; olfactory dysfunction.