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Dal Bò E, Natali L, Gentili C, Cecchetto C. Low odor awareness predicts reduced olfactory abilities in women with depressive symptoms, but not with anxiety symptoms. J Affect Disord 2023; 338:171-179. [PMID: 37290528 DOI: 10.1016/j.jad.2023.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 05/12/2023] [Accepted: 06/04/2023] [Indexed: 06/10/2023]
Abstract
BACKGROUND Olfactory disorders and affective symptoms are tightly related. However, the factors underlying this association are not yet understood. One candidate factor is "odor awareness": the degree of attention individuals pays to the odors. However, the association between odor awareness and olfactory abilities in individuals with affective symptoms has not been clarified yet. METHOD The present study examined whether odor awareness may moderate (a) the relation between olfactory dysfunctions and depressive and anxiety symptoms; (b) the relation between the perceptual ratings of the odors and depressive and anxiety symptoms in a sample of healthy women (n = 214). Self-report measures of depression and anxiety were collected, whereas the Sniffin' Stick test was employed to measure olfactory abilities. RESULTS Linear regression analysis revealed that individuals with higher depressive symptoms presented lower olfactory abilities and that odor awareness was a significant moderator of the association between depressive symptoms and olfactory abilities. Anxiety symptoms were not related to any of the olfactory abilities considered, and this relationship did not change according to odor awareness. The familiarity rating of the odor was significantly predicted by odor awareness. These results were confirmed by Bayesian statistics. LIMITATIONS The sample was composed only of women. CONCLUSIONS In a healthy population of women, only the presence of depressive symptoms is related to reduced olfactory performance. Odor awareness may be implicated in the development and maintenance of olfactory dysfunction; hence it could be used as a useful target for specific treatments in clinical settings.
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Affiliation(s)
- Elisa Dal Bò
- Padova Neuroscience Center (PNC), University of Padua, Via Orus 2/B, 35131 Padua, Italy; Department of General Psychology, University of Padua, Via Venezia 8, 35131 Padua, Italy.
| | - Ludovica Natali
- Department of General Psychology, University of Padua, Via Venezia 8, 35131 Padua, Italy; Centro di Ateneo Servizi Clinici Universitari Psicologici (SCUP), Via Belzoni, 84, 35121 Padua, Italy
| | - Claudio Gentili
- Padova Neuroscience Center (PNC), University of Padua, Via Orus 2/B, 35131 Padua, Italy; Department of General Psychology, University of Padua, Via Venezia 8, 35131 Padua, Italy; Centro di Ateneo Servizi Clinici Universitari Psicologici (SCUP), Via Belzoni, 84, 35121 Padua, Italy
| | - Cinzia Cecchetto
- Padova Neuroscience Center (PNC), University of Padua, Via Orus 2/B, 35131 Padua, Italy
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Herrmann T, Koeppel C, Linn J, Croy I, Hummel T. Olfactory brain activations in patients with Major Depressive Disorder. Sci Rep 2023; 13:10072. [PMID: 37344484 DOI: 10.1038/s41598-023-36783-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 06/09/2023] [Indexed: 06/23/2023] Open
Abstract
Depression is associated with reduced olfactory function. This relationship is assumed to be based on either a reduced olfactory bulb volume or diminished functioning of higher cortical areas. As previous results are controversial, we aimed to re-evaluate central olfactory processing in depression. We recorded the BOLD signal of 21 patients with Major Depressive Disorder and 21 age and gender matched healthy controls during odor presentation. In addition, we measured the individual olfactory bulb volume, tested odor identification and odor threshold, and asked for hedonic odor perception. In both groups, odor presentation led to a pronounced activation of primary olfactory areas. However, secondary olfactory areas were significantly less activated in depressed individuals. The two groups did not differ in olfactory bulb volume. Our results point towards altered olfactory processing in patients in those regions that relate to sensory integration and attention allocation. Difficulties in cognitive processing could impact olfactory function in depression. We are therefore in favor of a top-down mechanism originating in higher cortical areas explaining parts of the relation between depression and olfaction.
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Affiliation(s)
- Theresa Herrmann
- Department of Otorhinolaryngology, Smell and Taste Clinic, TU Dresden, Dresden, Germany.
| | - Carina Koeppel
- Department of Clinical Psychology, Friedrich Schiller University, Jena, Germany
| | - Jennifer Linn
- Department of Neuroradiology, TU Dresden, Dresden, Germany
| | - Ilona Croy
- Department of Clinical Psychology, Friedrich Schiller University, Jena, Germany
| | - Thomas Hummel
- Department of Otorhinolaryngology, Smell and Taste Clinic, TU Dresden, Dresden, Germany
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3
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Marin C, Alobid I, Fuentes M, López-Chacón M, Mullol J. Olfactory Dysfunction in Mental Illness. Curr Allergy Asthma Rep 2023; 23:153-164. [PMID: 36696016 PMCID: PMC9875195 DOI: 10.1007/s11882-023-01068-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2023] [Indexed: 01/26/2023]
Abstract
PURPOSE OF REVIEW Olfactory dysfunction contributes to the psychopathology of mental illness. In this review, we describe the neurobiology of olfaction, and the most common olfactory alterations in several mental illnesses. We also highlight the role, hitherto underestimated, that the olfactory pathways play in the regulation of higher brain functions and its involvement in the pathophysiology of psychiatric disorders, as well as the effect of inflammation on neurogenesis as a possible mechanism involved in olfactory dysfunction in psychiatric conditions. RECENT FINDINGS The olfactory deficits present in anxiety, depression, schizophrenia or bipolar disorder consist of specific alterations of different components of the sense of smell, mainly the identification of odours, as well as the qualifications of their hedonic valence (pleasant or unpleasant). Epidemiological findings have shown that both environmental factors, such as air pollutants, and inflammatory disease of the upper respiratory tract, can contribute to an increased risk of mental illness, at least in part, due to peripheral inflammatory mechanisms of the olfactory system. In this review, we describe the neurobiology of olfaction, and the most common olfactory function alterations in several psychiatric conditions and its role as a useful symptom for the differential diagnosis. We also highlight the effect of inflammation on neurogenesis as a possible mechanism involved in olfactory dysfunction in these psychiatric conditions.
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Affiliation(s)
- Concepció Marin
- INGENIO, IRCE, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), CELLEX, Department 2B, Villarroel 170, 08036, Barcelona, Catalonia, Spain. .,Centre for Biomedical Investigation in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain.
| | - Isam Alobid
- INGENIO, IRCE, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), CELLEX, Department 2B, Villarroel 170, 08036, Barcelona, Catalonia, Spain.,Centre for Biomedical Investigation in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain.,Rhinology Unit and Smell Clinic, ENT Department, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Mireya Fuentes
- INGENIO, IRCE, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), CELLEX, Department 2B, Villarroel 170, 08036, Barcelona, Catalonia, Spain.,Centre for Biomedical Investigation in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain
| | - Mauricio López-Chacón
- INGENIO, IRCE, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), CELLEX, Department 2B, Villarroel 170, 08036, Barcelona, Catalonia, Spain.,Centre for Biomedical Investigation in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain.,Rhinology Unit and Smell Clinic, ENT Department, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Joaquim Mullol
- INGENIO, IRCE, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), CELLEX, Department 2B, Villarroel 170, 08036, Barcelona, Catalonia, Spain. .,Centre for Biomedical Investigation in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain. .,Rhinology Unit and Smell Clinic, ENT Department, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain.
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Leon M, Woo CC. Olfactory loss is a predisposing factor for depression, while olfactory enrichment is an effective treatment for depression. Front Neurosci 2022; 16:1013363. [PMID: 36248633 PMCID: PMC9558899 DOI: 10.3389/fnins.2022.1013363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
The loss of olfactory stimulation correlates well with at least 68 widely differing neurological disorders, including depression, and we raise the possibility that this relationship may be causal. That is, it seems possible that olfactory loss makes the brain vulnerable to expressing the symptoms of these neurological disorders, while daily olfactory enrichment may decrease the risk of expressing these symptoms. This situation resembles the cognitive reserve that is thought to protect people with Alzheimer’s neuropathology from expressing the functional deficit in memory through the cumulative effect of intellectual stimulation. These relationships also resemble the functional response of animal models of human neurological disorders to environmental enrichment, wherein the animals continue to have the induced neuropathology, but do not express the symptoms as they do in a standard environment with restricted sensorimotor stimulation.
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Affiliation(s)
- Michael Leon
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
- *Correspondence: Michael Leon,
| | - Cynthia C. Woo
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
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5
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Chao Y, Woosch D, Pieniak M, Hummel T. Gender difference in ratings of odor intensity during olfactory training. J SENS STUD 2022. [DOI: 10.1111/joss.12784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yun‐Ting Chao
- Smell and Taste Clinic Department of Otorhinolaryngology, TU Dresden Dresden Germany
- Division of Rhinology, Department of Otorhinolaryngology‐Head and Neck Surgery Taipei Veterans General Hospital Taipei
- Institute of Brain Science National Yang Ming Chiao Tung University Taipei
| | - Dorothea Woosch
- Smell and Taste Clinic Department of Otorhinolaryngology, TU Dresden Dresden Germany
| | - Michal Pieniak
- Smell and Taste Clinic Department of Otorhinolaryngology, TU Dresden Dresden Germany
- University of Wrocław, Faculty of Historical and Pedagogical Sciences Institute of Psychology Wrocław Poland
| | - Thomas Hummel
- Smell and Taste Clinic Department of Otorhinolaryngology, TU Dresden Dresden Germany
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6
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Chen Y, Zhan Y, Qiu Y, Zhao J, Zou L. Odor Identification Ability as a Mediator of Schizotypal Traits and Odor Hedonic Capacity in Non-Clinical Children and Adolescents. Brain Sci 2022; 12:brainsci12050534. [PMID: 35624921 PMCID: PMC9138986 DOI: 10.3390/brainsci12050534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 12/07/2022] Open
Abstract
Background: Previous studies have investigated the relationship between schizotypal traits and odor identification ability as well as the relationship between schizotypal traits and odor hedonic capacity in adults. However, very little is known about the relationship among these three factors, especially in children and adolescents. The current study aimed to explore the relationship among these three factors in children and adolescents as well as the potential role of odor identification ability. Method: A total of 355 non-clinical children and adolescents (aged 9−16 years) were recruited in the study. They were asked to complete the Universal Sniff Test (U-Sniff), the Chemosensory Pleasure Scale for Children (CPS-C), and the Schizotypal Personality Questionnaire—Child (SPQ-C). Results: The SPQ-C scores were negatively correlated with both the odor identification scores and the odor hedonic scores (p = 0.022 and p < 0.001, respectively). Only the interpersonal−affective factor of the SPQ-C was negatively correlated with the odor identification scores (p = 0.031). The odor identification scores were significantly positively associated with the odor hedonic scores (p < 0.001). Moreover, the relationship between odor hedonic capacity and schizotypal traits, especially the interpersonal−affective factor, was mediated by odor identification ability. Conclusions: Schizotypal traits were negatively correlated with both odor identification ability and odor hedonic capacity in children and adolescents, while odor identification ability was found to mediate the relationship between odor hedonic capacity and schizotypal traits, especially the interpersonal−affective factor. Our study indicated that improving odor identification ability through olfactory training may have a positive influence on odor hedonic capacity in individuals with schizotypal traits.
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Affiliation(s)
- Ying Chen
- Chemical Senses and Mental Health Lab, Department of Psychology, School of Public Health, Southern Medical University, Guangzhou 510515, China; (Y.C.); (Y.Z.); (Y.Q.); (J.Z.)
| | - Yuyang Zhan
- Chemical Senses and Mental Health Lab, Department of Psychology, School of Public Health, Southern Medical University, Guangzhou 510515, China; (Y.C.); (Y.Z.); (Y.Q.); (J.Z.)
| | - Yiqi Qiu
- Chemical Senses and Mental Health Lab, Department of Psychology, School of Public Health, Southern Medical University, Guangzhou 510515, China; (Y.C.); (Y.Z.); (Y.Q.); (J.Z.)
| | - Jiubo Zhao
- Chemical Senses and Mental Health Lab, Department of Psychology, School of Public Health, Southern Medical University, Guangzhou 510515, China; (Y.C.); (Y.Z.); (Y.Q.); (J.Z.)
- Department of Psychiatry, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Laiquan Zou
- Chemical Senses and Mental Health Lab, Department of Psychology, School of Public Health, Southern Medical University, Guangzhou 510515, China; (Y.C.); (Y.Z.); (Y.Q.); (J.Z.)
- Department of Psychiatry, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
- Correspondence: ; Tel.: +86-20-62789234
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Abstract
Olfactory loss is associated with symptoms of depression. The present study, conducted on a large cohort of mostly dysosmic patients, aimed to investigate whether improvement in olfactory performance would correspond with a decrease in depression severity. In 171 participants (157 dysosmic), we assessed olfactory function and severity of depression before and after an average interval of 11 months, with many patients showing improvement in olfactory function. Separate analyses were conducted for (a) the whole group of patients and (b) the group of dysosmic patients using both classic and Bayesian approaches. For odor identification, Student t test demonstrated that the whole sample improved consistently, especially within the group of dysosmic patients. The dysosmic group also improved in odor threshold and overall olfactory function. Pearson correlation showed that an increase in olfactory function was associated with a decrease in depression severity, particularly in dysosmic patients. To conclude, the present results indicate that symptoms of depression change with olfactory function in general and odor identification in particular.
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8
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Chen B, Espin M, Haussmann R, Matthes C, Donix M, Hummel T, Haehner A. The Effect of Olfactory Training on Olfaction, Cognition, and Brain Function in Patients with Mild Cognitive Impairment. J Alzheimers Dis 2021; 85:745-754. [PMID: 34864678 DOI: 10.3233/jad-215257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The olfactory system is affected very early in Alzheimer's disease and olfactory loss can already be observed in patients with mild cognitive impairment (MCI), an early stage of AD. OBJECTIVE The aim of this randomized, prospective, controlled, blinded study was to evaluate whether olfactory training (OT) may have an effect on olfactory function, cognitive impairment, and brain activation in MCI patients after a 4-month period of frequent short-term exposure to various odors. METHODS A total of 38 MCI outpatients were randomly assigned to OT or a control training condition, which were performed twice a day for 4 months. Olfactory testing, comprehensive neuropsychological assessment, and magnetic resonance imaging were performed before and after training. RESULTS The results suggested that OT exhibited no significant effect on olfaction and cognitive function. However, OT exhibited a positive effect on frontal lobe activation (left middle frontal gyrus and orbital-frontal cortex) but exhibited no effect on grey matter volume. Moreover, the change of olfactory scores was positively associated with the change of frontal activation. CONCLUSION OT was found to have a limited effect on olfaction and cognition in patients with MCI compared to a non-OT condition but increased their functional response to odors in frontal area.
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Affiliation(s)
- Ben Chen
- Department of Otorhinolaryngology, Smell & Taste Clinic, TU Dresden, Dresden, Germany.,Department of Geriatric Psychiatry, Memory Clinic, The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, Guangdong Province, China
| | - Melanie Espin
- Department of Otorhinolaryngology, Smell & Taste Clinic, TU Dresden, Dresden, Germany
| | - Robert Haussmann
- Department of Psychiatry and Psychotherapy, TU Dresden, Dresden, Germany
| | - Claudia Matthes
- Department of Psychiatry and Psychotherapy, TU Dresden, Dresden, Germany
| | - Markus Donix
- Department of Psychiatry and Psychotherapy, TU Dresden, Dresden, Germany.,Deutsches Zentrum für Neurodegenerative Erkrankungen e.V. (DZNE), Dresden, Germany
| | - Thomas Hummel
- Department of Otorhinolaryngology, Smell & Taste Clinic, TU Dresden, Dresden, Germany
| | - Antje Haehner
- Department of Otorhinolaryngology, Smell & Taste Clinic, TU Dresden, Dresden, Germany
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9
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Odours count: human olfactory ecology appears to be helpful in the improvement of the sense of smell. Sci Rep 2021; 11:16888. [PMID: 34413403 PMCID: PMC8376892 DOI: 10.1038/s41598-021-96334-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/09/2021] [Indexed: 02/07/2023] Open
Abstract
Odours modify human behaviour. Research in this field develops rapidly, providing more and more exciting discoveries. In this context, our daily odorous environment has been surprisingly poorly explored. The aim of our study was to quantify olfactory perception and preliminarily identify factors affecting the frequency of odorous experiences. We were also interested in knowing whether human olfactory ecology relates with olfactory performance. In this study, patients with olfactory deficits (n = 62) and healthy controls (n = 97) had their olfactory threshold and odour identification abilities measured before and after a two-week intervention comprising counting of conscious perception of odours naturally occurring in the environment. In both groups, we observed enhanced olfactory performance after the intervention suggesting that (1) the conscious focus on odours may change its perception, and that (2) social and physical environment can effectively stimulate the human olfactory system, presumably supporting the improvement of olfactory sensitivity.
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10
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Oleszkiewicz A, Bottesi L, Pieniak M, Fujita S, Krasteva N, Nelles G, Hummel T. Olfactory training with Aromastics: olfactory and cognitive effects. Eur Arch Otorhinolaryngol 2021; 279:225-232. [PMID: 33864109 PMCID: PMC8051546 DOI: 10.1007/s00405-021-06810-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/08/2021] [Indexed: 11/24/2022]
Abstract
Purpose The olfactory system can be successfully rehabilitated with regular, intermittent stimulation during multiple daily exposures to selected sets of odors, i.e., olfactory training (OT). OT has been repeatedly shown to be an effective tool of olfactory performance enhancement. Recent advancements in studies on OT suggest that its beneficial effects exceed olfaction and extend to specific cognitive tasks. So far, studies on OT provided compelling evidence for its effectiveness, but there is still a need to search for an optimal OT protocol. The present study examined whether increased frequency of OT leads to better outcomes in both olfactory and cognitive domains. Method Fifty-five subjects (28 females; Mage = 58.2 ± 11.3 years; 26 patients with impaired olfaction) were randomly assigned to a standard (twice a day) or intense (four times a day) OT. Olfactory and cognitive measurements were taken before and after OT. Results OT performed twice a day was more effective in supporting olfactory rehabilitation and interventions targeted to verbal semantic fluency than OT performed four times a day, even more so in subjects with lower baseline scores. Conclusions OT is effective in supporting olfactory rehabilitation and interventions targeted to verbal semantic fluency. However, it may be prone to a ceiling effect, being efficient in subjects presenting with lower baseline olfactory performance and lower verbal semantic fluency. Supplementary Information The online version contains supplementary material available at 10.1007/s00405-021-06810-9.
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Affiliation(s)
- Anna Oleszkiewicz
- Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Fetscherstrasse 74, 01307, Dresden, Germany. .,Institute of Psychology, University of Wroclaw, ul. Dawida 1, 50-527, Wroclaw, Poland.
| | - Laura Bottesi
- Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Fetscherstrasse 74, 01307, Dresden, Germany
| | - Michal Pieniak
- Institute of Psychology, University of Wroclaw, ul. Dawida 1, 50-527, Wroclaw, Poland
| | - Shuji Fujita
- Sony Corporation, New Business & Technology Development Group, 1-7-1 Konan Minato-ku, Tokyo, 108-0075, Japan
| | - Nadejda Krasteva
- Sony Europe B.V., RD Center Stuttgart Laboratory 2, Hedelfingerstr. 61, 70327, Stuttgart, Germany
| | - Gabriele Nelles
- Sony Europe B.V., RD Center Stuttgart Laboratory 2, Hedelfingerstr. 61, 70327, Stuttgart, Germany
| | - Thomas Hummel
- Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Fetscherstrasse 74, 01307, Dresden, Germany
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11
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Eliyan Y, Wroblewski KE, McClintock MK, Pinto JM. Olfactory Dysfunction Predicts the Development of Depression in Older US Adults. Chem Senses 2020; 46:5983672. [PMID: 33197253 DOI: 10.1093/chemse/bjaa075] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Neuroanatomic connections link the olfactory and limbic systems potentially explaining an association between olfactory dysfunction and depression. Some previous studies have demonstrated that olfactory dysfunction is associated with increased depressive symptoms. However, these studies were cross-sectional and unable to establish which develops first. We used longitudinal data to determine if impaired odor identification increased subsequent depressive symptoms or vice versa. We assessed olfaction and depression in the National Social Life, Health, and Aging Project, a nationally representative, 15-year longitudinal study of older US adults. Olfaction was measured using a validated odor identification test (Sniffin' Sticks). Depressive symptoms were measured using a modified version of the validated Center for Epidemiological Studies Depression Scale. Multivariable logistic regression models examined the temporal relationships between developing olfactory dysfunction and depression while accounting for demographics, disease comorbidities, alcohol use, smoking, and cognition. Older adults with olfactory dysfunction had concurrent frequent depressive symptoms (odds ratio [OR] = 1.20, 95% confidence interval [CI] = 1.00-1.43). Among healthy adults at baseline, those who had olfactory dysfunction were more likely to develop frequent depressive symptoms 5 or 10 years later (OR = 2.22, 95% CI = 1.13-4.37). Conversely, those with frequent depressive symptoms at baseline were not more likely to develop olfactory dysfunction 5 or 10 years later. We show for the first time that olfactory dysfunction predicts subsequent development of depression in older US adults. These data support screening for depression in older adults with chemosensory impairment and set the stage for disentangling the relationship between olfaction and depression.
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Affiliation(s)
- Yazan Eliyan
- Pritzker School of Medicine, The University of Chicago, Chicago, IL, USA
| | - Kristen E Wroblewski
- Department of Public Health Sciences, The University of Chicago, Chicago, IL, USA
| | - Martha K McClintock
- Department of Comparative Human Development, The University of Chicago, Chicago, IL, USA.,Department of Psychology, The University of Chicago, Chicago, IL, USA
| | - Jayant M Pinto
- Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, The University of Chicago, Chicago, IL, USA
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