We thank Professor Sachdev for his letter and we certainly agree that further studies on the antidepressant effects of tDCS are needed and that the standards of application of a given therapy in any part of the world should be matched. It is certainly not acceptable that inferior treatments are used in developing countries. However, although antidepressants are often available in developing countries, problems with distribution and management of these medications often preclude regular and effective clinical treatment. For instance, in São Paulo, a relatively rich city in Brazil, shortage of antidepressants is common (Brazilian Ministry of Health website, http://portal.saude.gov.br/saude/). Those with depression are regularly faced with the choice between stopping antidepressant treatment or paying for it with their own money. Poor patients often have to interrupt their treatment, risking worsening or relapse of their depression. The situation is even worse in poorer countries. Furthermore, it is well established that higher prevalence rates of depression are found among poor, illiterate and urban migrants (Reference Almeida-Fiho, Lessa and MagalhaesAlmeida-Filho et al, 2004). Therefore, those most in need are less able to afford regular antidepressant treatment.

We agree that medications should be the first line of treatment for those with newly diagnosed depression. However, we cannot ignore the fact that many in poor areas are not being treated for depression at all. Therefore, our intention is to simulate the search for new, inexpensive approaches for the treatment of depression. Our suggestion of tDCS is based on several well-conducted studies showing its modulatory effects on brain activity (Reference Nitsche, Liebetanz and AntalNitsche et al, 2003), past positive trials of this technique in depression (Reference LolasLolas, 1977) and our preliminary data showing a significant antidepressant effect (Reference Fregni, Boggio and NitscheFregni et al, 2005). The main differences between the current tDCS protocols and those used in the 1960s and '70s derive from recent knowledge of stimulation to optimise cortical modulation and therefore clinical effects (Reference Nitsche, Liebetanz and AntalNitsche et al, 2003). Furthermore, substantial evidence from studies of transcranial magnetic stimulation and electroconvulsive therapy suggests that electrical stimulation is a powerful treatment for depression (Reference George, Nahas and LiGeorge et al, 2002).

Our message is simple: a large number of those with depression are suffering because they cannot afford medicine, therefore new solutions should be offered. Transcranial direct current stimulation might represent such a solution and should be investigated further.