The suggestion by Fregni et al (Reference Fregni, Boggio and Nitsche2005) that transcranial direct current stimulation (tDCS) might be an inexpensive solution to the lack of resources for the treatment of depression in developing countries is well meaning but does not take into account the real reasons for the poor uptake of psychiatric treatments. If, as the authors state, the uptake is only 34% in a resource-rich country such as the USA with its high educational levels and awareness campaigns, a rate of 17% in Brazil is not surprising and is most likely not due to the lack of affordable drugs (Reference Chisholm, Sanderson and Ayuso-MateosChisholm et al, 2004). Cheap and effective, if not the latest, antidepressant drugs are usually available in most countries. In making their suggestion, the authors also ignore the expert opinion regarding the first-line management of depression around the world (Reference CrawfordCrawford, 2004). Most commentators would agree that this should be pharmacotherapy and not direct magnetic or electrical stimulation of the brain. The lack of primary healthcare facilities in many countries makes the suggestion of tDCS as a primary intervention impractical.

My major concern, however, is not that the authors recommend tDCS as a first-line intervention but that they recommend it as an intervention at all. By basing their recommendation on just one unpublished modern study, these well-respected scientists appear to have gone beyond the available evidence. Transcranial direct current stimulation is not a new intervention for depression, with a number of studies published in the 1960s and '70s (Reference Bindman, Lippold and RedfearnBindman et al, 1964; Reference Lippold and RedfearnLippold & Redfearn, 1964; Reference LolasLolas, 1977). However, the results were not uniformly positive and certainly not persuasive enough for this intervention to have been adopted by clinicians. Although I acknowledge that our knowledge of the brain has improved, Fregni et al do not present evidence to show how modern tDCS is superior to that used four decades ago. We need to know a lot more about tDCS before it can be accepted as an effective treatment, and must await the results of many ongoing trials. In the meantime, those with depression in the developing world should be dissuaded from unplugging their car batteries and clamping the leads on to their foreheads.