To conduct a prospective, randomized trial to compare the efficacy of a group mindfulness-based intervention adapted for social anxiety disorder (MBI-SAD) versus cognitive behavior group therapy (CBGT).

The main aim of this comparative trial is to determine if the MBI-SAD will be noninferior to CBGT in improving core symptoms of social anxiety disorder, depressive symptoms, self, esteem, disability and quality of life. A secondary aim is to examine whether treatment gains are maintained over a 6-month period. Exploratory aims of the study are to: 1) determine if the MBI-SAD enhances self-compassion and mindfulness relative to CBGT; 2) determine if changes in self-compassion and mindfulness mediate the clinical response to the MBI-SAD; and 3) explore moderators of treatment response.

Inclusion Criteria:

• DSM-5 diagnosis of social anxiety disorder (SAD) of at least moderate severity
• Montgomery Asberg Depression Rating Scale score ≤ 25
• Comorbid depressive disorders, panic disorder, agoraphobia, generalized anxiety disorder, specific phobias, eating disorders are allowed as long as the SAD is primary and predominates the clinical picture.

Exclusion Criteria:

• Coexisting Axis I disorders excluding those listed in the inclusion criteria
• Coexisting medical conditions that can alter the clinical presentation of SAD (e.g. Parkinson's disease)
• Lifetime history of bipolar disorder or psychotic symptoms
• Substance-related disorders in the last 12 months
• Acutely suicidal or history of suicide attempt in the past five years
• History of non-suicidal self-injurious behavior in the last 12 months
• Currently receiving psychotherapy
• Currently engaged in a regular meditation or yoga practice
• Unable to attend weekly group sessions