Some numbers on tDCS research

For medical science to prove that a particular intervention works for a particular condition (depression) or to make a neurophysiological change (improving memory) there has to be numerous studies showing statistical success. It is best when different research methods are used, and repeated over and over again to show consistency. And normally the studies start out small and then larger ones are funded.

For tDCS, the research is very broad, from depression to memory, from pain to Parkinson's; it is so broad it makes me a little skeptical and I wondered how much research has been done on various medical conditions and non medical interventions.

Just recently, in pubmed, I did a simple search of tDCS + (topic) and recorded the number of papers that come up from the search. The results are shown below. I understand that this is only an indication of what is being researched (not all are directly related and all are certainly not positive), but I thought it was interesting nonetheless.

Hits on Pubmed

tDCS and Learning                         322
tDCS and Stroke                             288
tDCS and Memory                          214
tDCS and Depression                     208
tDCS and Pain                                162
tDCS and Safety                             108
tDCS and Cognitive Enhancement  55
tDCS and Bipolar                           31
tDCS and Parkinson's                     25
tDCS and Alzheimer's                    13