RecruitingBehavioural interventionMBSR Mechanisms in GADThe purpose of this study is to understand the neural mechanisms that drive response to MBSR compared to stress education in patients with generalized anxiety disorder (GAD), and to examine the degree to which sex differences in MBSR response are explained by sex differences in these mechanisms. A total of 150 eligible participants with a primary diagnosis of GAD will be randomized to either an 8-week group MBSR or stress education program. The study will include preliminary screening, experimental visits, including fMRI, group intervention visits, and assessments at baseline, endpoint, and 3-month follow-up.