Olfactory sensitivity in Autism Spectrum Disorder

Aim: Abnormalities in olfactory sensitivity have been previously reported in individuals with Autism Spectrum Disorders (ASD) (1, 2). However, little is still known about odour threshold, identification and discrimination in ASD. Aim of this study was to examine odour threshold, identification and discrimination in a group of individuals with ASD, compared to typically developing (TD) controls. Methods: olfactory function were studied in 10 participants with ASD (mean age 19.3±2 years, 8 boys) and 10 controls (mean age 22±2 years, 8 boys). We tested olfactory threshold, identification and discrimination with the Sniffin’ Sticks test. Participants with ASD had an IQ mean 103.2±18.5. All controls were not reported for intellectual disabilities. Results: Our results indicated that, while all the participants with TD had an odour threshold in the normal range, all the participants with ASD showed different levels of hyposmia: moderate (50%), mild (40%) and severe hyposmia (10%). Moreover, participants with ASD were significantly impaired regarding odour detection threshold in comparison with TD controls (U=13.00; p<0.05) and odour discrimination (U=10.00, p<0.05). There were not significant differences between participants with ASD and TD in olfactory identification (U= 24.00, p>0.05). Conclusion: in line with previous study (1,2), our results confirmed impaired odour perception in individuals with ASD, specifically in olfactory threshold and in odour discrimination. References: • Bennetto et al., 2007 • Dudova et al., 2011