Association Between Anxious Symptom Severity and Olfactory Impairment in Young Adults with Generalized Anxiety Disorder: A Case–Control Study

The findings of olfaction are inconsistent in anxiety disorders, and few studies have reported on the olfactory performance in generalized anxiety disorder (GAD). Therefore, we aim to investigate the olfactory function of patients with GAD and the association between olfactory function and anxiety symptoms.We conducted a case-control study by selecting 107 patients with GAD and 107 healthy controls matched for sex and age, to investigate olfaction deficits in GAD and the association between anxiety severity and olfaction. All patients were treatment-naïve prior to the inclusion. Anxiety severity and olfaction were assessed by the Hamilton anxiety rating scale (HAM-A) and the Sniffin' Sticks test (SST), respectively. Partial correlations were used to analyze the relationship between olfaction and anxiety severity. False discovery rate (FDR) correction was used in multi-correlation analyses.Compared with healthy controls, patients in the GAD group demonstrated odor threshold, discrimination and identification deficits. In the moderate/severe anxiety subgroup, discrimination score was significantly and inversely correlated with the somatic anxiety score (γ=-0.44, q = 0.03), and identification score was significantly and inversely correlated with the HAM-A total score (γ=-0.42, q= 0.04). The TDI score (the sum of threshold, discrimination and identification scores) was significantly and inversely correlated with the somatic (γ=-0.44, q = 0.04) and psychic (γ=-0.45, q = 0.04) anxiety scores in the moderate/severe anxiety subgroup.This study demonstrated the olfactory impairment in patients with GAD and that poorer odor discrimination was correlated with greater severity of somatic anxiety.