title: Utility of the Leyton Obsessional Inventory to distinguish OCD and OCPD.
abstract: The Leyton Obsessional Inventory (LOI) is a self-report questionnaire that assesses obsessional symptoms. The ability of the LOI to distinguish between obsessive-compulsive disorder (OCD) and obsessive-compulsive personality disorder (OCPD) has not been adequately addressed. Our purpose is to identify dimensions of obsessional symptoms from the LOI and determine how well they distinguish between OCD and OCPD. The LOI was completed by 488 participants diagnosed by trained clinicians. Factor analysis was performed on responses to the interference items of the LOI. The relationship between the factors, OCD and OCPD was evaluated using logistic regression. Five factors underlying the LOI were identified: (I) obsessional ruminations and compulsions, (II) ordering and arranging, (III) organizing activities, (IV) contamination, and (V) parsimony. Factors I, III, and IV were strongly associated with OCD. Only Factor II was associated with OCPD. Factor IV was negatively associated with obsessive-compulsive personality traits. LOI factors are useful in discriminating between OCD and OCPD. Obsessional ruminations and compulsions, organizing activities, and contamination fears may indicate OCD, and ordering and arranging symptoms may indicate OCPD rather than OCD. Parsimony may indicate neither disorder, and contamination, the absence of OCPD traits compared with the other LOI factors. These findings may contribute to effective diagnosis and treatment by allowing the LOI to screen for OCD and OCPD in a population exhibiting obsessional symptoms and traits.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, School of Medicine, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA. davidwellen@hotmail.com
authors.forename: David
authors.initials: D
authors.lastname: Wellen
authors.forename: Jack
authors.initials: J
authors.lastname: Samuels
authors.forename: O Joseph
authors.initials: OJ
authors.lastname: Bienvenu
authors.forename: Marco
authors.initials: M
authors.lastname: Grados
authors.forename: Bernadette
authors.initials: B
authors.lastname: Cullen
authors.forename: Mark
authors.initials: M
authors.lastname: Riddle
authors.forename: Kung-Yee
authors.initials: KY
authors.lastname: Liang
authors.forename: Gerald
authors.initials: G
authors.lastname: Nestadt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003193:Compulsive Personality Disorder / Q000175:diagnosis* / Q000523:psychology; D003937:Diagnosis, Differential; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000523:psychology; D010555:Personality Inventory / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000706:statistics & numerical data; D015203:Reproducibility of Results