Grant: Doctoral Award - Frederick Banting and Charles Best Canada Graduate Scholarships

Generalized anxiety disorder (GAD) is a commonly diagnosed mental illness that can have profound effects on professional, personal, and social levels. Its main feature is excessive, uncontrollable worry about a number of events or activities occurring more days than not for at least six months. An empirically-supported cognitive-behavioural treatment (CBT) protocol has been developed based on a cognitive model of GAD that centres around intolerance of uncertainty. However, not all treated individuals achieve full remission of their disorder for reasons that have not been conclusively established. A potential barrier to effective GAD treatment may be Cluster C personality disorders: obsessive compulsive, avoidant, and dependent personality disorders. These disorders often co-occur with GAD, but there is a lack of consensus as to how this affects treatment response. This study will determine the role of Cluster C personality disorders in the CBT treatment of GAD. The main goals of the study are to determine if: 1) pre-treatment presence of a Cluster C personality disorder predicts poorer response to GAD treatment, and 2) pre-treatment severity of Cluster C personality disorders predicts poorer response to GAD treatment. The participants are 110 Francophone adults in Montreal between ages 18 and 65 with a primary diagnosis of GAD, recruited from the Anxiety Disorders Clinic of Sacré-Coeur Hospital. Our CBT treatment is administered over 14 weekly sessions with licensed psychologists. The treatment components target specific processes in our model of GAD while building tolerance and acceptance of uncertainty at each stage. This study will increase our understanding of the impact of Cluster C personality disorders on GAD treatment. If they have a significant impact on treatment outcomes this will inform clinical practice as to the importance of assessing for personality disorders and integrating symptom-specific interventions into the existing treatment.