EEG Changes in Schizophrenia Following tDCS: A Systematic Scoping Review

Strategic Insights -

Research has identified new findings on the effects of transcranial direct current stimulation (tDCS) on electroencephalographic (EEG) variables in schizophrenia. A systematic scoping review compiled data from 25 papers, which collectively reported 42 occurrences of EEG changes induced by tDCS. The majority of papers applied 20 minutes of 2 mA stimulation in a bicephalic montage, with the most investigated variable being the N100 potential. The results showed that N100 was the variable that responded most to tDCS stimulation, with an 80% response rate, while gamma activity had a 67% response rate, and MMN showed a 60% response rate.

Key Takeaways:

  • The systematic scoping review included 25 papers that investigated the effects of tDCS on EEG variables in schizophrenia, totaling 42 occurrences.
  • The majority of papers (76%) applied 20 minutes of 2 mA stimulation in a bicephalic montage.
  • The N100 potential was the most investigated variable, followed by MMN, N100, P300, EEG coherence, gamma activity, beta, and alpha power.
  • N100 was the variable that responded most to tDCS stimulation, with an 80% response rate.
  • Gamma activity had a 67% response rate, MMN showed a 60% response rate, and coherence, alpha, and beta power had a 50% response rate.
  • All papers investigating P300 reported no significant results.
  • Other EEG parameters were investigated only once.
  • The review concluded that EEG changes induced by tDCS in schizophrenia predominantly affected the sensory-auditory potential N100, had a lesser impact on pre-attentive potential MMN, and showed no observable effect on higher-order cognitive potentials, such as P300.
  • Public health organizations and researchers interested in understanding the effects of tDCS on schizophrenia can contact Julia Diniz Grossi, LiNC-Laboratory of Integrative Neuroscience, Dept. of Psychiatry, Federal University of Sao Paulo, Sao Paulo, Brazil.
  • Authors of this study include July Silveira Gomes, Yanina Leon Uscapi, Andre Russowsky Brunoni, Ary Gadelha, and Acioly Lt Lacerda.

Statistics:

  • 25 papers were included in the review
  • 42 occurrences of EEG changes were reported
  • 76% of papers applied 20 minutes of 2 mA stimulation
  • 80% of studies reported significant changes in N100 potential
  • 67% of studies reported significant changes in gamma activity
  • 60% of studies reported significant changes in MMN potential
  • 50% of studies reported significant changes in coherence, alpha, and beta power
  • All 10 papers investigating P300 reported no significant results

Sources:

  • NewsRx. Studies from Federal University of Sao Paulo Yield New Information about Schizophrenia (EEG Changes in Schizophrenia Following tDCS: A Systematic Scoping Review). Mental Health Weekly Digest. October 20, 2025; p 1081.
  • Clinical EEG and Neuroscience, 2025:15500594251384350.