Enhancing Cognition in Older Persons with Depression or Anxiety with a Combination of Mindfulness-Based Stress Reduction (MBSR) and Transcranial Direct Current Stimulation (tDCS): Results of a Pilot Randomized Clinical Trial

OBJECTIVES: Individuals with subjective memory complaints and symptoms of depression and/or anxiety are at high risk for further cognitive decline, and possible progression to dementia. Low-burden interventions to help slow or prevent cognitive decline in this high-risk group are needed. The objective of this study is to assess the feasibility of combining Mindfulness-Based Stress Reduction (MBSR) with transcranial direct current stimulation (tDCS) to increase putative benefits of MBSR for cognitive function and everyday mindfulness in depressed or anxious older adults with subjective cognitive decline. METHODS: We conducted a two-site pilot double-blind randomized sham-controlled trial, combining active MBSR with either active or sham tDCS. The intervention included weekly in-class group sessions at the local university hospital and daily at-home practice. Anodal tDCS was applied for 30 min during MBSR meditative practice, both in-class and at-home. RESULTS: Twenty-six individuals with subjective cognitive complaints and symptoms of depression and/or anxiety were randomized to active (n = 12) or sham tDCS (n = 14). The combination of MBSR and tDCS was safe and well tolerated, though at-home adherence and in-class attendance were variable. While they were not statistically significant, the largest effect sizes for active vs. sham tDCS were for everyday mindfulness (d = 0.6) and social functioning (d = 0.9) (F((1,21)) = 3.68, p = 0.07 and F((1,21)) = 3.9, p = 0.06, respectively). CONCLUSIONS: Our findings suggest that it is feasible and safe to combine tDCS with MBSR in older depressed and anxious adults, including during remote, at-home use. Furthermore, tDCS may enhance MBSR via transferring its meditative learning and practice into increases in everyday mindfulness. Future studies need to improve adherence to MBSR with tDCS. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03653351 and NCT03680664). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12671-021-01764-9.