Reduced olfactory sensitivity in subjects with depressive symptoms.

Background: Clinical studies suggest that olfactory sensitivity is reduced in major depression. Nevertheless, only little is known about the relationship between depressive symptoms and olfactory functions in healthy subjects.

Methods: The present study investigated the association between depressive symptoms and olfactory performance in 48 healthy subjects (14 male). First depressive symptoms were assessed using the Beck Depression Inventory, following by olfactory testing. Olfactory threshold and discrimination performance was assessed as well as emotional arousal and pleasantness during the testing procedure.

Results: We observed a significant negative correlation between olfactory sensitivity and depressive symptoms while olfactory discrimination was not related to depressive symptoms.

Limitations: The degree of depressive symptoms was assessed by questionnaire. A clinical interview might assess depressive symptoms more accurate.

Conclusion: We conclude that depressive symptoms are related to a reduced olfactory sensitivity. The observed relation between reduced olfactory sensitivity and depressive symptoms could be mediated by functional deviations within brain structures subserving primary olfactory processing such as amygdala and piriform cortex which is in line with results showing abnormal activity pattern in the amygdala and other brain regions in depression.