Perceived threat of social odors mediates the relationship between social anxiety symptoms and olfactory acuity

Anxiety is characterized by an attentional bias towards potentially threatening stimuli and such stimuli may be more easily recognized by people with increased sensory sensitivity. One of the functions of olfaction is to detect dangers which links this sense with experiencing anxiety. Neural pathways of anxiety and olfactory perception overlap and to a great extent rely on the same structure, i.e., amygdala. However, the behavioral relationship between anxiety and olfactory sensitivity has been overlooked. To this end, we recruited 127 participants aged 18-39 years (M=20.8, SD=3.5; 86 women) who completed the GAD-7 questionnaire measuring generalized anxiety symptoms and Liebowitz Social Anxiety Scale. Additionally, participants completed an odor sorting task with six concentrations
of eight odors. The odors represented two categories: environmental (turpentine, motor oil, rose, orange), and social (artificial flatulence, isovaleric acid 0.5%, feminine and masculine perfumes). Additionally, participants rated perceived threat of each odor. Linear regression and mediation analyses showed that social anxiety symptoms predicted olfactory acuity towards socially-relevant odors (p=.009) and that this relationship was mediated by perceived threat of these odors (p=.0.22). Generalized anxiety symptoms also predicted olfactory acuity towards environmental odors (p=.013), but perceived threat of environmental odors did not mediate this relationship (p=.713). Overall, our findings shed new light on the mechanism underlying olfactory perception in people with social and generalized anxiety symptoms. Socially anxious individuals perceive socially-meaningful odors as more threatening and in turn they are more effective at distinguishing between subtle differences in odors concentrations.