Publications (11) View all
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Article: Hedonic Olfactory Perception in Depression: Relationship between Self-Evaluation and Autonomic Response
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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.Psychology 11/2012; 3:959-965. -
Article: State and Trait Olfactory Markers of Major Depression
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ABSTRACT: Nowadays, depression is a major issue in public health. Because of the partial overlap between the brain structures involved in depression, olfaction and emotion, the study of olfactory function could be a relevant way to find specific cognitive markers of depression. This study aims at determining whether the olfactory impairments are state or trait markers of major depressive episode (MDE) through the study of the olfactory parameters involving the central olfactory pathway. In a pilot study, we evaluated prospectively 18 depressed patients during acute episodes of depression and 6 weeks after antidepressant treatment (escitalopram) against 54 healthy volunteers, matched by age, gender and smoking status. We investigated the participants' abilities to identify odors (single odors and in binary mixture), to evaluate and discriminate the odors' intensity, and determine the hedonic valence of odors. The results revealed an ''olfactory anhedonia'' expressed by decrease of hedonic score for high emotional odorant as potential state marker of MDE. Moreover, these patients experienced an ''olfactory negative alliesthesia'', during the odor intensity evaluation, and failed to identify correctly two odorants with opposite valences in a binary iso-mixture, which constitute potential trait markers of the disease. This study provides preliminary evidence for olfactory impairments associated with MDE (state marker) that are persistent after the clinical improvement of depressive symptoms (trait marker). These results could be explained by the chronicity of depression and/or by the impact of therapeutic means used (antidepressant treatment). They need to be confirmed particularly the ones obtained in complex olfactory environment which corresponds a more objective daily life situation. Copyright: ß 2012 Naudin et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.PLoS ONE 01/2012; 7(10):e46938. · 4.09 Impact Factor -
Article: [Decision making in the elderly: which tools for its evaluation by the clinician?].
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ABSTRACT: Numerous decision-making situations occur in the activities of daily living. The consequences of the decision-making capacity disturbances may have a great impact on the patient's autonomy, financial management, and his or her reaction to a diagnosis as well as the ability to accept a therapeutic option or give informed consent. Decision-making is a complex and multi-dimensional process and brings into play attention, memory and executive functions, which are processed in the prefrontal cortex, particularly vulnerable in aging. A better comprehension of the mechanisms of decision-making, and of the resulting social consequences of their dysfunction may improve autonomy of the elderly. Unfortunately, we still lack appropriate tools to explore decision-making in routine practice.Psychologie & neuropsychiatrie du vieillissement 09/2010; 8(3):201-7. · 0.45 Impact Factor -
Article: Olfactory anhedonia and negative olfactory alliesthesia in depressed patients.
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ABSTRACT: The present study aimed to investigate olfactory anhedonia and olfactory negative alliesthesia in depressed patients. Two odorants, one with pleasant (vanillin), and one with unpleasant (butyric acid) hedonic valence were evaluated by 30 depressed inpatients and 30 controls (healthy subjects, matched by age and gender). Participants explored the hedonic valence, intensity (discrimination) and perceived quality (identification) of 16 different stimuli (3 concentrations of odorants, their 9 combinations, and 1 control containing distilled water). The hedonic perception showed that patients perceived the unpleasant odorant as significantly more unpleasant than controls (olfactory negative alliesthesia). Concerning the intensity ratings, controls were able to discriminate between all concentrations of odorants, while patients discriminated between the different concentrations only for the unpleasant component and not for the vanillin (olfactory anhedonia). Regarding the identification task in an iso-intense unmixed odorants mixture, patients perceived significantly less the pleasant odorant than the unpleasant one (olfactory anhedonia), whereas controls perceived both odorants equally well. These results support the notion of an olfactory perception impairment in depression. Further studies are needed to replicate these findings and to confirm that such olfactory anhedonia or/and olfactory negative alliesthesia could be a state or a trait of depression.Psychiatry Research 03/2010; 176(2-3):190-6. · 2.52 Impact Factor -
Article: Olfaction: a potential cognitive marker of psychiatric disorders.
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ABSTRACT: Cognitive deficits are well documented in psychiatric disorders, particularly in schizophrenia and depression. Cognitive activity roots in perceptions. However, research on sensorial alterations in psychiatric conditions has mainly focused on visual or auditory processes and less on olfaction. Here, we examine data on olfactory deficits in psychiatric patients using a systematic review of recent publications. Schizophrenic patients are mainly characterized by no reliable change in odour sensitivity and by a deficit in odour identification, recognition and discrimination. Depressed patients principally exhibit a deficit in the hedonic aspects of this perception, even if, in some case, alterations in sensitivity or identification are also found. Changes in odour perception are also found in dementia and in some neurodegenerative disease, but in this case alterations concern all aspects of the sensorial experience (detection threshold, identification and recognition). Taken together, these data indicate that olfactory abnormalities might be a marker of psychiatric conditions, with a specific pattern for each disease.Neuroscience & Biobehavioral Reviews 06/2008; 32(7):1315-25. · 8.65 Impact Factor
