The Effects of Deep TMS on QEEG Measures in Co-Occurring Major Depressive Disorder and Early-Stage Alzheimer’s Disease: A Pilot Study

Major Depressive Disorder (MDD) and Alzheimer's disease (AD) represent two of the most prevalent diseases worldwide. Notably, it is estimated that 30%-50% of individuals with AD have co-occurring MDD and there are overlapping symptoms across numerous domains. In this pilot study, a Deep TMS protocol (targeting the left frontal and bilateral temporal regions) was delivered for 36 sessions to patients with co-occurring MDD and early-stage AD (N = 12). All participants received the treatment and there was no control condition. The treatment yielded a response rate of 83.33% (defined by a ≥50% reduction in depressive symptoms on the Patient Health Questionnaire-9 [PHQ-9]) and a remission rate of 50.00% (PHQ-9 score of 4 or less following treatment). Further, participants displayed reductions in left prefrontal and right temporal delta power using QEEG analysis pre- and -post treatment. Alpha coherence was also enhanced in key areas. The observed shift in neurophysiological measures suggested reduced cortical slowing and dysconnectivity, which are hallmark traits in MDD and AD. This proof-of-concept study suggests that further research on the application of Deep TMS (paired with QEEG) for early-stage AD is warranted.