Safety of Repeated Twice-daily 30 Minutes of 2 mA tDCS in Depressed Patients

Aims: Transcranial direct stimulation (tDCS) is recently discussed as a therapeutic option in psychiatric disorders and has brought preliminary convincing results in the treatment of depressive disorders. Hence the optimal stimulation parameters still remain elusive as randomized controlled trials over last years used divergent stimulation protocols and duration, frequency, and current strength still have to be standardized.

Presentation of Cases: In this case series we report on the safety of twice daily 30 min tDCS at 2 mA over longer stimulation periods and interval treatment. Six patients (mean age 59.5±22.3, age range 29-87 years) with major depressive disorder received 20 to 31 tDCS treatments within 14 and 50 days, including acute treatment series and maintenance treatment. In the majority of participants, tDCS exerted antidepressant effects. tDCS was well tolerated and there were no clinically relevant adverse events.

Discussion: These preliminary data suggest safety and tolerability of twice-daily 30 min tDCS even in a prolonged protocol.

Conclusion: tDCS is gaining growing importance as a therapeutic tool in neuropsychiatric disorders and seems to be safe even when applied extensively.