EROL scale: a new behavioural olfactory measure and its relationship with anxiety and depression symptoms

The main objective of this study was to develop and validate a new olfactory measure that assesses the influence of olfaction on several emotional, behavioural, and cognitive issues: The Relational Scale of Olfaction (EROL). A secondary objective was to explore the relationship between the olfactory function and the anxiety and depression symptoms by means of EROL and the Hospital Anxiety and Depression Scale (HADS). A positive relationship between anxiety symptoms and the olfactory function was hypothesized. Regarding depressive symptoms, a significant relationship with the olfactory scores was not expected.

Psychometric properties of EROL scale and correlations between HADS and EROL were tested in a sample from the general population.

EROL showed an adequate level of test-retest reliability (ICC=.748) and good internal consistency (Cronbach’s alpha=.761). Convergent validity with other olfactory measures was satisfactory. A one-factor solution was found for the scale. HADS showed a significant relationship with EROL (r=.280, p<.01), but the analysis through dimensions revealed that only the anxiety subscale correlated significantly and moderately with the olfactory measure (r=.325, p<.001), whereas the correlation with the depression subscale was non-significant (r=.146, p>.05).

Given that EROL displayed good psychometrical properties, it appears as a suitable tool to assess the olfactory function in general population. The relationship between this olfactory scale and anxiety symptoms found in this study is an interesting issue that requires further research.