Altered Olfactory Processing of Stress-Related Body Odors and Artificial Odors in Patients with Panic Disorder

Abstract

BackgroundPatients with Panic Disorder (PD) direct their attention towards potential threat, followed by panic attacks, and increased sweat production. Onés own anxiety sweat odor influences the attentional focus, and discrimination of threat or non-threat. Since olfactory projection areas overlap with neuronal areas of a panic-specific fear network, the present study investigated the neuronal processing of odors in general and of stress-related sweat odors in particular in patients with PD.MethodsA sample of 13 patients with PD with/ without agoraphobia and 13 age- and gender-matched healthy controls underwent an fMRI investigation during olfactory stimulation with their stress-related sweat odors (TSST, ergometry) as well as artificial odors (peach, artificial sweat) as non-fearful non-body odors.Principal FindingsThe two groups did not differ with respect to their olfactory identification ability. Independent of the kind of odor, the patients with PD showed activations in fronto-cortical areas in contrast to the healthy controls who showed activations in olfaction-related areas such as the amygdalae and the hippocampus. For artificial odors, the patients with PD showed a decreased neuronal activation of the thalamus, the posterior cingulate cortex and the anterior cingulate cortex. Under the presentation of sweat odor caused by ergometric exercise, the patients with PD showed an increased activation in the superior temporal gyrus, the supramarginal gyrus, and the cingulate cortex which was positively correlated with the severity of the psychopathology. For the sweat odor from the anxiety condition, the patients with PD showed an increased activation in the gyrus frontalis inferior, which was positively correlated with the severity of the psychopathology.ConclusionsThe results suggest altered neuronal processing of olfactory stimuli in PD. Both artificial odors and stress-related body odors activate specific parts of a fear-network which is associated with an increased severity of the psychopathology.

Preliminary evidence for differential olfactory and trigeminal processing in combat veterans with and without PTSD

“…Our finding of elevated BR intensity ratings in both PTSD groups, regardless of time since trauma, is consistent with a growing literature showing enhanced odor threat processing with increased state/trait anxiety ( Krusemark and Li, 2012 , La Buissonniere-Ariza et al, 2013 ) and across a variety of fear-related disorders including panic disorder, social anxiety, as well as PTSD ( Croy et al, 2010 , Pause et al, 2009 , Wintermann et al, 2013 ). However, elevated BR intensity ratings in the PTSD group with more distant trauma conflicts with this group's level of general olfactory functioning.…”

“…However, indices of olfactory function (e.g. odor detection and/or identification) among anxiety and other fear-related disorders including PTSD have been inconsistent ( Vasterling et al, 2000 , Dileo et al, 2008 , Goldberg et al, 1991 , Segalas et al, 2011 , Locatelli et al, 1996 , Kopala and Good, 1996 , Hermesh et al, 1999 , Fenger et al, 2005 , Croy et al, 2010 , Schecklmann et al, 2013 , Wintermann et al, 2013 ). This variability suggests that additional unknown factors may play a role (e.g.…”

The Explorative Analysis to Revise Fear Network Model for Panic Disorder

“… 46 In addition, the activities in SMG and temporal lobe were also associated with the severity of psychopathology in PDO. 60 The decreased connectivity strength between PHG.L and SMG also corresponded to the altered activities in temporal lobe and SMG in PDO. The study of neutral face task found decreased activities in CAL and other visual areas of PDO patients.…”

Oxytocin reduces a chemosensory-induced stress bias in social perception

“…Furthermore, women seem to be more receptive to stress-related olfactory cues compared to men, with women exhibiting a reduced positive emotional priming effect [15] and enhanced neural responses in the prefrontal cortex [16]. Importantly, individuals with increased stress vulnerability, such as patients with social anxiety [17] or panic disorder [18], display heightened sensitivity towards these olfactory stress cues. Olfactory dysfunctions have also been described as a feature of the clinical phenotype of other psychiatric disorders including schizophrenia, depression [19], and post-traumatic stress disorder [20], rendering the olfactory pathway a potentially pivotal target for therapeutic interventions.…”