About 15 years ago, when I was deep in my studies to
become a Doctor of Naturopathic Medicine (I have a medical background, but now
I am an EE, and hope to be a successful businessman in a few years time…) my
daily experience was immersed in my studies and my colleagues. The subculture
would deceive where we truly were: common health problems were low cholesterol
and fatigue, there was little obesity, pharmaceuticals as intervention were
only the very last resort. This is the perception I have to be aware of when
thinking of the safety of TDCS.
I have been an active participant in DIY TDCS for
about two years, initially just practicing, then becoming a little more vocal.
And in that community the safety of TDCS is so wholeheartedly believed, known,
that there is definitely a risk of accusation if speaking otherwise. But then I
step out into the “real world”, with scary descriptions and still the “don’t do
this at home” mentality. It is important for someone to have this perspective,
it is a new technology and there are still questions, but using scare tactics
to disregard the technology, or to mock it, or to attempt to slow its
dissemination into the general public is foolish, and maybe immoral.
In the research community, the message is similar to
the DIY (and much more complicated to read) but definitely more tempered. The
work is there: a systematic review on the adverse effects of TDCS found pretty
much the same as all the others (39% itching, 22% tingling, 15% headache, 9%
burning) (Brunoni 2009). Other papers have similar adverse effects, I have also
seen fatigue, the percentages are different, but the adverse effects are
similar (a list of some papers below). To be straight, the research is on
commercial devices (but not those designed for TDCS), with experienced research
personnel running the studies. Not just putting a 9V battery on the head.
But that is the crazy thing about TDCS. People, most
likely in the thousands, are putting 9V batteries on their head (hopefully at
least through a couple resistors and good electrodes), as well as designing and
building simple current regulating circuits to produce real, effective TDCS
devices. And the consequences? I have certainly read examples of people saying
it is greatly helping with their medical condition, helping them pass exams,
learn languages. Is this scientifically proving TDCS, hell no, it is more
exciting. It is the beginning of TDCS as it is disseminated through the greater
population; psychonauts performing the long term experiments of TDCS that is lacking
in the research. These are people experimenting with poor equipment, perhaps making
mistakes in their designs or builds, with varied medical conditions, varied
personalities (and maybe personality disorders) and the disasters have not occurred
(fingers crossed). But despite the scare tactics they are taking the chance and
striving nonetheless to better themselves. This is the exciting part.
Arul-Anandam
AP, Loo C, Sachdev. Transcranial direct current stimulation - what is the
evidence for its efficacy and safety? Medicine Reports 2009, 1:58
Bikson M,
Datta A, lwassif M. Establishing safety limits for transcranial direct current
stimulation. Clin Neurophysiol 2009;120(6):1161
Brunoni
AR, Amadera J, Berbel B, Volz MS, Rizzerio BG, Fregni F. A Systematic review on
reporting and assessment of adverse effects associated with transcranial direct
current stimulation. Int J Neuropsypharm 2011;14:1133-1145
Iyer MB,
Mattu U, Grafman J, Lomarev M, Sato S, Wasserman EM. Safety and cognitive
effect of frontal DC brain polarization in healthy individuals. Neurology
2005;64:872-875.
Nitsche
MA, Liebetanz K, Lang N, Antal A, Tergan F, Paulus W. Safety criteria for
transcranial direct current stimulation in humans. Clin Neurophysiol 2003;
114(11):2220-2.
Poreisz
C, Boros K, Antal A, Paulus W. Safety aspects of tDCS concerning healthy
subjects and patients. Brain Res Bull 2007;72:208-214.