Pergamon Journalof Anxiety Disorders, Vol. 10,No. 5, pp. 379-391.1996 Copyright 8 1996Elsevier Science Ltd Printedin the USA. All rightsreserved 0887-618596 S15.00+ .OO PII Soss7-618s(%)ooo18-7 Thought-Action Fusion in Obsessive Compulsive Disorder Roz SHAFXAN, PH.D., DANA S. THORDARSON, M-A., AND S. RACHMAN, PH.D.* University of British Columbia Abstract - Recent psychometric results suggested that the phenomenon of thought- action fusion (TAF) is implicated in obsessive compulsive disorder (OCD). The con- struct of TAF has two components: (a) the belief that thinking about an unacceptable or disturbing event makes it mote likely to happen and (b) the belief that having an unac- ceptable thought is the moral equivalent of carrying out the unacceptable or disturbing action. The consttuct of TAF is explored, and its relevance to msponsibility and obse.5 sive-compulsive disorder examined. A highly reliable questionnaire to measure TAF has been developed, and psychometric data obtained from two studies are presented. TAF was higher in obsessional samples than in nonobsessional samples, particularly the belief that thinking about a negative event involving other people makes the event more likely to happen. You have heard that it was said, “Do not commit adultery.” But now I tell you: Anyone who looks at a woman and wants to possessher is guilty of committing adultery with her in his heart. Matthew X.27-28. It has been suggested that some patients with OCD experience thought-action fusion (TAP) in which thoughts, particularly unwanted intrusive thoughts, are interpreted as having special significance (Rachman, 1993). Preliminary research has provided support for this hypothesis (Rachman, Thordarson, Shafran, & Woody, 1995), and TM appears to have two components: 1. The belief that thinking about an unacceptable or disturbing event makes that event more probable, more likely to happen in reality. This will be This research was supported by a grant from the British Columbia Health Research Foundation. The first author was supported by a Wellcome Trust Prize Studentship. The authors would like to thank Nichole Fairbrother, Adam Radomsky, and the anonymous reviewers for their helpful comments. Requests for reprints should be sent to to S. Rachman, Ph.D., Department of Psychology, University of British Columbia 2136 West Mall, Vancouver, B.C., Canada V6T lZ4. 379