The effect of the Home‐based tDCS on behavioral and electrophysiological parameters in patients with both MCI and depression: A randomized double‐blind placebo‐controlled trial

Abstract

AbstractAs depressive symptom is considered as a prodrome, a risk factor of progression from mild cognitive impairment (MCI) to dementia, improving depressive symptoms should be considered a clinical priority in transcranial direct current stimulation (tDCS) intervention in patients with MCI. We aimed to comprehensively evaluate the efficacy of the home‐based and remotely monitored tDCS in patients with both MCI and depression, by integrating cognitive, psychological, and electrophysiological indicators. In a 6‐week, randomized, double blind and sham‐controlled study, thirty‐seven community‐dwelling patients were randomly assigned to either an active or a sham stimulation group, and received 30 home‐based session of 2 mA tDCS for 30 min located anode over left and cathode over right dorsolateral prefrontal cortex. We measured depressive symptoms, neurocognitive function, and resting‐state electroencephalography (EEG). Active tDCS was not significantly different from sham tDCS in the effects of both depressive symptoms and cognitive functions. However, compared to sham stimulation, active tDCS decreased and increased the activation of delta and beta frequencies, respectively. Moreover, the increase in beta activity was correlated with the cognitive enhancement only in the active group. It was not possible to reach a definitive conclusion regarding the efficacy of tDCS on depression and cognition in patients with both MCI and depression. Nevertheless, the relationship between the changes of electrophysiology and cognitive performance suggests potential neuroplasticity enhancement implicated in cognitive processes by tDCS.