The structure of obsessive-compulsive symptoms.

In the present study, the structure of obsessive-compulsive symptoms was investigated by means of the Padua Inventory (PI). Simultaneous Components Analysis on data from obsessive-compulsives (n = 206), patients with other anxiety disorders (n = 222), and a non clinical sample (n = 430) revealed a five-factor solution. These factors are: (I) impulses; (II) washing; (III) checking; (IV) rumination; and (V) precision. Forty-one items were selected as measure of these factors. The reliability for the five subscales, assessing each of the five factors, was found to be satisfactory to excellent. Four subscales (washing, checking, rumination and precision) discriminated between panic disorder patients, social phobics and normals on the one hand and obsessive compulsives on the other. The Impulses subscale discriminated between obsessive-compulsives on the one hand and normals on the other, but not between obsessive-compulsives and social phobics or panic patients. Some evidence in support of the construct validity was found. The Padua Inventory-Revised (41-items) appears to measure the structure of obsessive compulsive symptoms: The main types of behaviours and obsessions as seen clinically are assessed by this questionnaire, apart from obsessional slowness.