Thought-action fusion as a causal factor in the development of intrusions.

Thought-action fusion refers to the tendency to treat thoughts and actions as equivalents. Some authors (e.g., Rachman, 1997; Behaviour Research and Therapy, 35, 793-802) have suggested that thought-action fusion plays a role in the etiology of obsessive intrusions. The present study sought to test this idea. Subjects (n = 19) in the experimental condition underwent a bogus EEG recording session. They were informed that the apparatus was able to pick up the word 'apple' and that thoughts of that word could result in the administration of electrical shocks to another person. After having spent 15 minutes in the EEG laboratory, experimental subjects and controls (n = 26) completed a short questionnaire containing items about characteristics of the target thought (e.g., frequency, aversiveness). Results indicate that thought-action fusion, indeed, promotes intrusive thinking in that it results in a higher frequency of target thoughts, more discomfort, and more resistance. Thus, the current findings support the idea that thought-action fusion may contribute to the development of obsessive intrusions.