Date of Award


Publication Type

Doctoral Thesis

Degree Name





Psychology, Control of thoughts, Obsessive-compulsion disorder


Josée Jarry




Cognitive theory of obsessions hypothesizes that faulty appraisals of intrusive thoughts are paramount in the development and persistence of obsessive-compulsive disorder (OCD). Types of faulty appraisals include interpretations of excessive responsibility for preventing an adverse outcome (responsibility), appraisals of exaggerated personal importance (importance of thoughts), and interpretations that focus on having total control over one's own thoughts (control of thoughts). Previous research suggests that importance and control of thoughts appraisals (Ferguson, Jarry, & Jackson, 2006) and beliefs (Obsessive Compulsive Cognitions Working Group, 2005) are better described as one construct. Although there are numerous experimental studies suggesting that appraisals of excessive responsibility lead to more severe OCD symptoms, only two have demonstrated this effect with importance of thoughts appraisals (Teachman, Woody, & Magee, 2006; Teachman & Clerkin, 2007), and none have experimentally examined the combined effect of importance appraisals and efforts at mental control. The present research investigates the impact of an experimental manipulation of importance appraisals and attempts at mental control on the severity of OCD associated manifestations. Participants had an unwanted mental intrusion provoked through the use of a well-established intrusive thought provocation procedure (Rachman, Shafran, Mitchell, Trant, & Teachman, 1996). Appraisals of importance were experimentally manipulated by systematically varying information given to participants about having an intrusive thought (i.e., whether it is meaningful or not). Attempts at mental control were manipulated using a thought suppression task, as suppression is a common strategy used by people in response to an intrusive thought in order to regain mental control. Results revealed that participants who were exposed to importance interpretations, and those who were not given any feedback about their intrusive thought (Control group), reported more severe dysfunctional appraisals of importance and mental control, as well as higher levels of OCD associated symptoms than did those who had their intrusive thought normalized. Participants who were instructed to exercise mental control via thought suppression did not report more severe levels of obsessive-compulsive symptoms than did those who were not given such instructions. Finally, the findings clearly suggest that psychoeducational information to normalize mental intrusions is beneficial.