Behaviour Research and Therapy 39 (2001) 947–959 www.elsevier.com/locate/brat Distinguishing obsessive features and worries: the role of thought–action fusion Meredith E. Coles * , Douglas S. Mennin, Richard G. Heimberg Adult Anxiety Clinic of Temple University, Department of Psychology, Temple University, Weiss Hall, 1701 North 13th Street, Philadelphia, PA 19122-6085, USA Received 8 June 2000 Abstract Obsessions are a key feature of obsessive–compulsive disorder (OCD), and chronic worry is the cardinal feature of generalized anxiety disorder (GAD). However, these two cognitive processes are conceptually very similar, and there is a need to determine how they differ. Recent studies have attempted to identify cognitive processes that may be differentially related to obsessive features and worry. In the current study we proposed that (1) obsessive features and worry could be differentiated and that (2) a measure of the cognitive process thought–action fusion would distinguish between obsessive features and worry, being strongly related to obsessive features after controlling for the effects of worry. These hypotheses were supported in a sample of 173 undergraduate students. Thought–action fusion may be a valuable construct in differentiating between obsessive features and worry.  2001 Elsevier Science Ltd. All rights reserved. Keywords: Thought-action fusion; Obsessive features; Worry 1. Distinguishing obsessive features and worries: the role of thought–action fusion Recent years have witnessed a surge in research attempting to clarify the relationship of specific cognitive constructs to particular anxiety disorders. These constructs include obsessions, a key feature of obsessive–compulsive disorder (OCD; e.g. Rachman, 1998) and worry, the cardinal feature of generalized anxiety disorder (GAD; e.g. Borkovec, 1994). The fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Associ- ation [APA], 1994, p. 422) defines obsessions as “recurrent and persistent thoughts, impulses, or images that are experienced, at some time during the disturbance, as intrusive and inappropriate * Corresponding author. Fax: +1-215-204-2155. E-mail addresses: mcoles@astro.ocis.temple.edu (M.E. Coles), rheimber@nimbus.ocis.temple.edu (R.G. Heimberg). 0005-7967/01/$ - see front matter  2001 Elsevier Science Ltd. All rights reserved. PII:S0005-7967(00)00072-3