The New Yorker magazine dated April 6, 2015 has an article on tDCS by Elif Batuman entitled, ELECTRIFIED: adventures in transcranial electrical direct-current stimulation. As one expects of a New Yorker article it is captivating and clear; it is also relatively short. Perhaps not so short. About 6,000 words. I had just finished 10 minutes of left frontal stimulation with the foc.us v.2 Gamer, so I might have been a more efficient reader than usual.
I have been personally experimenting with tDCS (transcranial electrical Direct-Current Stimulation) for a about a year, using the MindAlive Oasis Pro and the foc.us Gamer (v.2 is just out; I had found found v.1 uncontrollable and therefore unsatisfactory). For me, the effects seemed to be minimal (although I did not formally test myself and have noted an increase in apparent reading speed). However, I have recently been using it with a few ADHD patients who report a notable alertness. In the near future, we plan to try it clinically with depressed patients and experimentally with other conditions.
Bautman, in his New Yorker article, reports various effects depending on electrode placements. His main interest, it turned out, was in using it for depression. And he got a remarkable benefit. He concludes the article with speculation that tDCS may be an active placebo. You should be able to access the full article at http://www.newyorker.com/magazine/2015/04/06/electrified.
We will see how effective tDCS seems to be in our office and the EEGym®. My prediction is that we will have an add-on to neurofeedback treatment that for some patients may be significant.