The Leyton Obsessional Inventory: an analysis of the responses of 73 obsessional patients.

The Leyton Obsessional Inventory was administered to 73 obsessive-compulsive neurotics, and their responses compared with those of 100 normal subjects. The ratio of the mean patient to normal scores ranged from 2.4:1 for obsessional traits and 3.2:1 for symptoms to 6.2:1 for resistance and 12.5:1 for interference with other activities. A principal components analysis on the patients' replies produced 3 unitary components (household order, personal contamination, and doubting) plus 2 bipolar components (checking/parsimony and desire for closure/unpleasant ruminations). These appeared to be more definitive representations of components identified from a similar analysis on normal subjects, suggesting that obsessional neurotics differ from normal subjects quantitatively rather than qualitatively. A cluster analysis on the patients' responses produced 3 subgroups. Thirty-two patients were predominantly hesitant and indecisive ('doubters'), 30 were concerned with bodily and clothing contamination ('contaminators'), and 7 were preoccupied with checking ('checkers').