The proposed research will study the effects of Imaginal Rescripting (IR) for social anxiety disorder (SAD). IR guides patients to change their memories of past socially painful events. Initial studies have found that a single session of IR significantly reduces SAD symptoms, however it is not yet clear how or why IR works and whether its effects are long lasting. To answer these questions, the investigators will randomly assign adults with SAD to receive either IR, or two other types of brief psychological interventions: Imaginal Exposure and Supportive Counselling. Changes in participants' memories, social anxiety symptoms, quality of life, negative beliefs, and social behaviour over the course of a 6-month period will be assessed. This study will provide valuable insight into the short- and long-term effects of IR and clarify the mechanisms through which IR works. Ultimately, this knowledge will enable the development of more effective treatments and prevention programs for SAD.