The neural correlates of mindfulness-induced depression reduction in adults with autism spectrum disorder: A pilot study.

Adults with autism spectrum disorder (ASD) experience high rates of depression and anxiety, and some evidence suggests mindfulness-based stress reduction (MBSR) is effective in reducing these symptoms. However, the neural mechanisms of symptom alleviation, and benefit of MBSR beyond education/support groups are unknown. Maladaptive forms of self-reflection are linked to ASD, depression, and anxiety. In this pilot study, we hypothesized (a) MBSR would reduce depression and anxiety in adults with ASD and (b) a mechanism of symptom alleviation would be increased blood oxygen level-dependent signal in neural self-reflection hubs. Twenty-eight adults were randomly assigned to an 8-week MBSR group (n = 15) or a support group (n = 13) that met for the same amount of time with relaxation education materials. Based on previous self-reflection literature in ASD, regions of interest (ROIs) were middle cingulate cortex (MCC) and ventromedial prefrontal cortex (vmPFC). Only the MBSR group demonstrated significant reductions in depression, and neither group significantly changed in anxiety. Only the MBSR group increased activity of right MCC during self-reflection, and the increase correlated with depression alleviation. There were no changes in vmPFC for the MBSR group or either ROI for the support/education group. Seed-to-voxel connectivity analysis revealed that only the MBSR group increased functional connectivity between right MCC and pre/postcentral gyrus, suggesting MBSR may increase primary sensorimotor input to higher order cognitive brain regions. Taken together, MBSR may be effective for reducing depression in adults with ASD, and the neural mechanism may be increasing frontal circuit involvement during self-directed thought.