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Updated: Jul 25, 2025
10:42
A Free-breathing fMRI Method to Study Human Olfactory Function
Published on: July 30, 2017
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Olfactory Dysfunction and Depression Trajectories in Community-Dwelling Older Adults
Vidyulata Kamath1, Kening Jiang2,3, Kevin J Manning4
1Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Summary
Reduced sense of smell in older adults may predict new or worsening depression. Poor cognition, not inflammation, partially explains this link, highlighting olfaction
Area of Science:
- Gerontology
- Neuroscience
- Psychiatry
Background:
- Olfactory dysfunction is common in older adults.
- Late-life depression is a significant public health concern.
- The relationship between olfaction and depression requires further investigation.
Purpose of the Study:
- To examine the association between baseline olfactory performance and incident depressive symptoms.
- To investigate the link between olfaction and longitudinal depression trajectories in well-functioning older adults.
- To explore the mediating roles of inflammation and cognitive status.
Main Methods:
- Longitudinal study of 2,125 well-functioning older adults (71-82 years).
- Olfactory identification task, cognitive assessments, depressive symptom ratings, and inflammatory markers were measured over 8 years.
- Statistical models included complementary log-log, group-based trajectory, and multinomial logistic regression; mediation analysis was performed.
Main Results:
- Lower olfactory performance increased the risk of developing significant depressive symptoms (HR=1.04).
- Poorer olfaction was linked to higher risk of moderate/high depression trajectories (RRR=1.06).
- Poor cognitive status, but not inflammation, partially mediated the olfaction-depression relationship.
Conclusions:
- Suboptimal olfaction may indicate vulnerability to late-life depression.
- Olfactory decline could be a prognostic indicator for depression in older adults.
- Further research is needed on factors influencing olfaction and late-life depression.
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