Surreal illustration linking sense of smell and the brain, symbolizing mental health and early detection of psychosis.

Sniffing Out Psychosis: Can Your Sense of Smell Predict Mental Health?

"New research explores the link between olfactory function and psychosis risk in young adults, offering a potential early detection method."


The ability to smell, often taken for granted, is emerging as a potential indicator of deeper neurological processes. For years, researchers have observed a connection between a compromised sense of smell and various mental health conditions, most notably psychosis. Now, a new study delves into this relationship, specifically examining how olfactory function relates to cognitive abilities in young adults at clinical high risk for psychosis.

Psychosis, characterized by distorted perceptions of reality, typically emerges in early adulthood. Identifying individuals at risk before the full onset of the condition is crucial for early intervention and potentially mitigating the severity of the illness. This study, conducted in China, explores whether deficits in the sense of smell could serve as an early warning sign.

Researchers at the Second Xiangya Hospital and collaborating institutions investigated olfactory and cognitive functions in a group of Chinese individuals considered at clinical high risk for psychosis (CHRs). Using a specially adapted olfactory test for East Asians, the study aimed to determine if these individuals exhibited differences in their sense of smell compared to healthy controls, and if these differences correlated with cognitive performance.

Smell Test as Early Indicator

Surreal illustration linking sense of smell and the brain, symbolizing mental health and early detection of psychosis.

The study compared 19 individuals at clinical high risk for psychosis (CHRs) with 37 healthy controls (HCs). Participants, aged 13-30, underwent olfactory testing using the Odor Stick Identification Test for Japanese (OSIT-J), adapted for use in East Asian populations. This test presents 12 familiar odors, requiring participants to identify each from a selection of options.

In addition to the smell test, all participants completed a series of cognitive assessments, including the Hopkins Verbal Learning Test-Revised (HVLT-R), Trail Making Test (TMT), and Stroop Color Word Test (SCWT). These tests measured verbal memory and executive function, providing a comprehensive overview of cognitive abilities.

  • CHRs scored significantly lower than HCs on the OSIT-J, indicating impaired olfactory identification.
  • CHRs also performed worse on all cognitive tests, demonstrating deficits in verbal memory and executive function.
  • Olfactory scores showed a moderate positive correlation with HVLT-R scores (verbal memory) and negative correlations with TMT-B and SCWT scores (executive function).
These findings suggest a strong link between olfactory and cognitive functions in individuals at high risk for psychosis. The impaired sense of smell, combined with reduced cognitive performance, could potentially serve as an early indicator of the condition. The use of the OSIT-J, a culturally relevant olfactory test, strengthens the validity of these results for East Asian populations.

A New Direction for Mental Health

This study provides compelling evidence for the potential of olfactory testing as a tool for early psychosis detection, particularly within East Asian populations. By identifying individuals at risk before the full onset of symptoms, interventions can be implemented to potentially delay or mitigate the severity of the illness.

While these findings are promising, further research is needed to validate these results and explore the underlying mechanisms connecting olfactory and cognitive functions in psychosis. Longitudinal studies, with larger and more diverse samples, are crucial to determine the precise timing of olfactory impairment and its predictive value.

Ultimately, this research highlights the importance of considering the sense of smell as a valuable indicator of mental health. Integrating olfactory assessments into routine screenings could revolutionize the early detection and intervention strategies for psychosis and other related conditions, paving the way for more proactive and personalized mental healthcare.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.psychres.2018.12.074, Alternate LINK

Title: Olfactory And Cognitive Functions In Chinese Individuals At Clinical High Risk For Psychosis

Subject: Biological Psychiatry

Journal: Psychiatry Research

Publisher: Elsevier BV

Authors: Ying He, Zongchang Li, Xiaoqian Ma, Liu Yuan, Lijun Ouyang, Jinsong Tang, Ming T. Tsuang, Xiaogang Chen

Published: 2019-02-01

Everything You Need To Know

1

What specific smell test was used in this research, and why?

The study uses the Odor Stick Identification Test for Japanese (OSIT-J), adapted for East Asian populations. This test involves identifying 12 familiar odors from a selection of options. The OSIT-J was chosen for its cultural relevance, making it suitable for the study's focus on young Chinese adults. The test results were compared between individuals at clinical high risk for psychosis (CHRs) and healthy controls (HCs) to identify any differences in olfactory function.

2

What is psychosis, and why is early detection important?

Psychosis is a mental health condition characterized by distorted perceptions of reality. It typically emerges in early adulthood. Early detection is crucial because it allows for timely interventions, potentially mitigating the severity of the illness. The research focuses on identifying individuals at clinical high risk for psychosis (CHRs) before they experience full-blown psychotic symptoms, enabling earlier treatment and support.

3

What cognitive tests were used in this study, and what do they measure?

The Hopkins Verbal Learning Test-Revised (HVLT-R), Trail Making Test (TMT), and Stroop Color Word Test (SCWT) were used. The HVLT-R assesses verbal memory, while the TMT and SCWT evaluate executive function. These cognitive tests provide a comprehensive overview of cognitive abilities, allowing researchers to correlate olfactory function with cognitive performance. The results showed that the CHRs performed worse on all cognitive tests demonstrating deficits in verbal memory and executive function which is linked to their olfactory issues.

4

Does this research show a connection between sense of smell and cognitive function?

Yes, the findings indicate a link between olfactory and cognitive functions in individuals at high risk for psychosis. Those at clinical high risk for psychosis (CHRs) scored significantly lower on the OSIT-J, showing impaired olfactory identification. These individuals also performed worse on cognitive tests, highlighting deficits in verbal memory and executive function. Furthermore, there was a correlation between olfactory scores and cognitive performance, suggesting that a compromised sense of smell could serve as an early indicator of the condition.

5

What are the main implications of this study's findings?

The study's implications are significant because they suggest that olfactory testing, specifically using the OSIT-J, can be a valuable tool for early psychosis detection, particularly in East Asian populations. By identifying individuals at clinical high risk for psychosis (CHRs) before the full onset of symptoms, interventions can be implemented. This early detection allows for timely interventions, potentially delaying or mitigating the severity of the illness. This could lead to more effective treatment strategies and better outcomes for individuals at risk.

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