Part 3. A question of perspective: The association between intrusive thoughts and obsessionality in 11 countries

• We administered a semi-structured interview of unwanted intrusive thoughts and questionnaires of obsessive compulsive symptoms, obsessional beliefs and depressive symptoms.
• We assessed 554 nonclinical individuals from 11 countries.
• Frequency more than control of unwanted intrusive thoughts was specifically associated with obsessive–compulsive symptoms.
• Dirt/contamination, doubt, and miscellaneous intrusions were uniquely related to obsessive–compulsive symptoms.

A key assumption of contemporary cognitive-behavioral models of obsessive–compulsive disorder (OCD) is that obsessional thoughts exist on a continuum with “normal” unwanted intrusive thoughts. Recently, however, some authors have challenged this notion. The present study aimed to clarify (a) the extent that different types of intrusive thoughts in nonclinical individuals are associated with obsessionality, (b) the relative contribution of frequency, distress and control ratings to obsessionality, and (c) the extent that existing findings (primarily from North American or European samples) generalize to other countries in the world. Five hundred and fifty-four non clinical individuals from 11 different countries were administered an interview assessing the presence, frequency, distress, and perceived control of different types of intrusive thoughts. Participants also completed measures of obsessional beliefs, obsessive–compulsive (OC) symptoms, and depression. Results from data analyses supported the universality of unwanted intrusive thoughts, the continuity of normal and abnormal obsessions, and the specificity of dirt/contamination, doubt and miscellaneous intrusions to OC symptoms. Implications for intrusive thoughts as a potential vulnerability factor for OCD are discussed.