Title:Transcranial Direct Current Stimulation for the Treatment of Refractory Symptoms of Schizophrenia. Current Evidence and Future Directions
Volume: 21
Issue: 23
Author(s): Marine Mondino, Jerome Brunelin, Ulrich Palm, Andre R. Brunoni, Emmanuel Poulet and Shirley Fecteau
Affiliation:
Keywords:
Auditory hallucinations, cognition, negative symptoms, schizophrenia, tDCS, transcranial direct current stimulation.
Abstract: Schizophrenia is a severe and frequent neuropsychiatric disorder. Despite antipsychotic medications, up
to 30% of patients with schizophrenia still report disabling treatment-resistant symptoms. Transcranial direct current
stimulation (tDCS) has been proposed as a novel method to alleviate such symptoms. Here, we review studies
investigating the effects of tDCS on symptoms, cognition, brain activity and cortical plasticity in patients with
schizophrenia. We provide an up-to-date and comprehensive overview of the use of tDCS in patients with schizophrenia. More specifically,
we first present the effects of tDCS on treatment-resistant symptoms of schizophrenia. We report that tDCS applied over the frontotemporal
regions reduced auditory hallucinations, with a mean 34% reduction of symptoms. Moreover, tDCS applied over both prefrontal
cortices reduced negative symptoms and catatonia. We discuss the need for further sham-controlled studies to confirm these effects. Second,
we present the impact of tDCS on cognitive functions in patients with schizophrenia. Positive effects of tDCS have been reported on
learning, working memory, attention and source-monitoring. Third, we review the effects of tDCS on brain activity in patients with
schizophrenia. Although only few studies investigated the effects of tDCS using neuroimaging technics, these studies are helpful at identifying
the mechanisms of action of tDCS in schizophrenia. Fourth, we present tDCS studies on cortical plasticity showing reduced cortical
plasticity in patients with schizophrenia that tDCS may beneficially modulate. Lastly, we discuss the safety aspects of tDCS in patients
with schizophrenia and potential directions to improve efficacy for this clinical populations.