The two dimensions of contamination fear in obsessive-compulsive disorder: Harm avoidance and disgust avoidance

• We hypothesized two motivational themes underlying contamination fear.
• Both harm avoidance and disgust avoidance can motivate contamination avoidance.
• We developed the Contamination Fear Core Dimensions Scale (CFCDS) – an 8-item self-report measure.
• Confirmatory factor analyses supported the hypothesized two-correlated-factors structure.
• The CFCDS also demonstrated good reliability, construct and criterion-related validity.

Contamination fear has always been considered a homogeneous symptom dimension. Compensatory behaviors (e.g., washing) are considered attempts to remove the contagion and to protect the individual from threats of illness; however, they may also be motivated by feelings of distress that are unrelated to any perceived harmful outcome, such as the feeling of disgust. Our hypothesis was that OCD patients with fear of harm resulting from contamination (harm avoidance [HA]) and OCD patients with fear of disgusting substances/persons (disgust avoidance [DA]) could be distinguished. To test this hypothesis, the Contamination Fear Core Dimensions Scale (CFCDS), an 8-item self-report measure aimed at operazionalizing the two facets of contamination fear, was developed. The scale was administered to 176 Italian OCD patients, together with a series of other self-report measures, and to 86 non-clinical participants. Confirmatory factor analyses supported the hypothesized two-correlated-factor structure in the clinical sample. The CFCDS also showed adequate reliability, construct and criterion-related validity. In particular, DA and HA subscales showed different patterns of association with other measures. In conclusion, this study provides preliminary evidence of the separability of two motivational dimensions of contamination fear and of specific associations between these and other relevant constructs.