Ten minutes of 1 mA transcranial direct current stimulation was well tolerated by children and adolescents: Self-reports and resting state EEG analysis

• Safety and tolerability of tDCS was assessed in children and adolescents.
• All participants tolerated the stimulation well.
• No pathological oscillations after 1 mA tDCS were detected.
• Subjects were unable to identify whether they had received active or sham stimulation.
• The results add a further piece of evidence of the safety of the tDCS protocols in pediatric population.

Transcranial direct current stimulation (tDCS) is a promising and well-tolerated method of non-invasive brain stimulation, by which cortical excitability can be modulated. However, the effects of tDCS on the developing brain are still unknown, and knowledge about its tolerability in children and adolescents is still lacking. Safety and tolerability of tDCS was assessed in children and adolescents by self-reports and spectral characteristics of electroencephalogram (EEG) recordings. Nineteen typically developing children and adolescents aged 11–16 years participated in the study. Anodal and cathodal tDCS as well as sham stimulation were applied for a duration of 10 min over the left primary motor cortex (M1), each with an intensity of 1 mA. Subjects were unable to identify whether they had received active or sham stimulation, and all participants tolerated the stimulation well with a low rate of adverse events in both groups and no serious adverse events. No pathological oscillations, in particular, no markers of epileptiform activity after 1 mA tDCS were detected in any of the EEG analyses. In summary, our study demonstrates that tDCS with 1 mA intensity over 10 min is well tolerated, and thus may be used as an experimental and treatment method in the pediatric population.