Development and initial validation of the obsessive beliefs questionnaire and the interpretation of intrusions inventory

In 1995 the Obsessive Compulsive Cognitions Working Group initiated a colle ctive process to develop two measures of cognition relevant to current cogn itive-behavioural models of OCD. An earlier report (Behav. Res. Therapy, 35 (1997) 667) describes the original process of defining relevant domains. T his article describes the subsequent steps of the development and validatio n process: item generation, scale reduction, and initial examination of rel iability and validity. Two scales were developed. The Obsessive Beliefs Que stionnaire consists of 87 items representing dysfunctional assumptions cove ring six domains: overestimation of threat, tolerance of uncertainty, impor tance of thoughts, control of thoughts, responsibility, and perfectionism. The Interpretation of Intrusions Inventory consists of 31 items that refer to interpretations of intrusions that have occurred recently. Three of the above domains are represented: importance of thoughts, control of thoughts, and responsibility. The item reduction and validation analyses were conduc ted on clinical and non-clinical samples from multiple sites. Initial exami nation of reliability and validity indicates excellent internal consistency and stability and encouraging evidence of validity. However, high correlat ions indicating overlap between some of the scales, particularly importance of thoughts, control of thoughts, and responsibility will need to be addre ssed in subsequent empirical and theoretical investigations. (C) 2001 Elsev ier Science Ltd. All rights reserved.