Hedonic Olfactory Perception in Depression: Relationship between Self-Evaluation and Autonomic Response

Boriana Atanasova,Wissam El-Hage,Frédéric Minier,Catherine Belzung,Philippe Gaillard

doi:10.4236/psych.2012.311144

Abstract

This study aimed to improve the understanding of hedonic perception in depression using the olfactory modality. We evaluated physiological (heart rate measures) and hedonic responses (subjective rating scale) obtained from 30 unipolar depressed inpatients and 30 healthy controls. The stimuli were two odorants with contrasting hedonic valence, vanillin (pleasant) and butyric acid (foul-smelling), presented at three different concentrations and in nine binary mixtures. Compared to controls, the depressed subjects had significantly increased heart rate response to olfactory stimuli, regardless of valence. These observations were not related to the severity of depression. For both groups, a significant negative correlation was found between the explicit hedonic rating and the implicit instantaneous heart rate measure. Together these pilot findings suggest that unipolar depression is associated with stronger physiological reactions to odorants and a negative bias when processing olfactory stimuli. Further studies are required to confirm these observations in larger groups of depressed subjects.

Highlights

IntroductionAnhedonia, and excessive negative affect (e.g. sadness, guilt) are the two cardinal symptoms of major depressive disorder (MDD) as defined by the DSM-IV (American Psychiatric Association, 1994)
Deficient positive affect, or anhedonia, and excessive negative affect are the two cardinal symptoms of major depressive disorder (MDD) as defined by the DSM-IV (American Psychiatric Association, 1994)
Recent studie has demonstrated that the unpleasant stimulus of butyric acid and the binary mixture of pleasant and unpleasant odours are perceived as significantly more unpleasant by depressed patients than by healthy controls

Summary

Introduction

Anhedonia, and excessive negative affect (e.g. sadness, guilt) are the two cardinal symptoms of major depressive disorder (MDD) as defined by the DSM-IV (American Psychiatric Association, 1994). In a recent metaanalysis, Bylsma et al (2008) suggested that depressed individuals had reduced emotional reactivity (i.e. intensity of the emotional response) to both positively and negatively valenced stimuli, with a larger reduction for positive than for negative stimuli as compared to healthy controls. Among the many studies in this field, only a few have explored the emotional and/or hedonic response to olfactory stimuli in depressed individuals, olfactory processing has been shown to have close links with emotional processing (Ehrlichman & Bastone, 1992; Zatorre et al, 2000). Recent studie has demonstrated that the unpleasant stimulus of butyric acid and the binary mixture of pleasant and unpleasant odours (butyric acid and vanillin) are perceived as significantly more unpleasant by depressed patients than by healthy controls

Methods

Results

Discussion

Conclusion