The focus of this study is to develop an understanding of the psychological and neural mechanisms that underlie treatment changes related to individual cognitive-behavioral therapy (I-CBT) for social anxiety disorder. All participants will be assessed using diagnostic interviews, questionnaires, computer tasks, and functional magnetic resonance imaging (fMRI) pre and post I-CBT, and will be followed for one year post treatment. Therapy will be offered for free. All participants will be screened for treatment and for fMRI eligibility. Our goal is to identify what changes with successful treatment and to begin to elucidate who will benefit from I-CBT.