Olfactory functioning

What is olfactory functioning in bipolar disorder?

Olfactory processes may be dysfunctional in people with bipolar disorder. These processes are hierarchical and involve lower-order processing (detection of the stimulus) and higher-order processing (discrimination and identification of the stimulus). Measures of olfactory acuity include odor detection, identification, discrimination, intensity, and quality. Odour detection occurs at the lowest chemical concentration needed to register an odourant. Odour identification draws on a person’s knowledge and memory to correctly label the smell. Odour discrimination involves comparing the differences between multiple stimuli, judging odours as pleasant or unpleasant, or comparing the relative concentration of odours.

What is the evidence for olfactory dysfunction in people with bipolar disorder?

Moderate to low quality evidence suggests poorer olfactory identification in people with bipolar disorder than in people without a mental illness, and better olfactory identification compared to people with psychosis. Olfactory hallucinations were particularly associated with depressive episodes in people with bipolar disorder.

September 2021

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Last updated at: 1:03 am, 17th October 2021
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