© 2005 The Royal College of Psychiatrists
Correspondence |
Transcranial direct current stimulation in developing countries
PO Box 233, Matraville, New South Wales 2036, Australia. E-mail: p.sachdev{at}unsw.edu..au
The suggestion by Fregni et al (2005) 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 (Chisholm 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 (Crawford, 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 By basing their recommendation on just one unpublished modern study, these well-respected scientists appear to have gone beyond the available evidence.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 (Bindman et al, 1964; Lippold & Redfearn, 1964; Lolas, 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.
EDITED BY KIRIAKOS XENITIDIS and KHALIDA ISMAIL
REFERENCES
- Bindman, L. J., Lippold, O. C. J. & Redfearn, J. W. T.
(1964) The action of brief polarizing currents on the
cerebral cortex of the rat. Journal of Physiology,
172, 369
-382.
[Free Full Text] - Chisholm, D., Sanderson, K., Ayuso-Mateos, J. L., et al
(2004) Reducing the global burden of depression.
Population-level analysis of intervention cost-effectiveness in 14 world
regions. British Journal of Psychiatry,
184, 393
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[Abstract/Free Full Text] - Crawford, M. J. (2004) Depression:
international intervention for a global problem. British Journal of
Psychiatry, 184, 379
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[Free Full Text] - Fregni, F., Boggio, P. S., Nitsche, M., et al
(2005) Transcranial direct current stimulation.
British Journal of Psychiatry,
186, 446
-447.
[Free Full Text] - Lippold, O. C. J. & Redfearn, J. W. T. (1964) Mental changes resulting from the passage of small direct currents through the human brain. British Journal of Psychiatry, 110, 768 -772.
- Lolas, F. (1977) Brain polarization: behavioral and therapeutic effects. Biological Psychiatry, 12, 37-47.[Medline]
Authors' reply
Harvard Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA. E-mail: ffregni{at}bidmc.harvard.edu
EDITED BY KIRIAKOS XENITIDIS and KHALIDA ISMAIL
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 (Almeida-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 (Nitsche et al, 2003), past positive trials of this technique in depression (Lolas, 1977) and our preliminary data showing a significant antidepressant effect (Fregni 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 (Nitsche 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 (George 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.
REFERENCES
- Almeida-Fiho, N., Lessa, I., Magalhaes, L., et al (2004) Social inequality and depressive disorders in Bahia, Brazil: interactions of gender, ethnicity, and social class. Social Science and Medicine, 59, 1339 -1353.[CrossRef][Medline]
- Fregni, F., Boggio, P., Nitsche, M., et al (2005) Treatment of major depression with transcranial direct current stimulation. Bipolar Disorders, in press
- George, M. S., Nahas, Z., Li, X, et al (2002) Novel treatments of mood disorders based on brain circuitry (ECT, MST, TMS, VNS, DBS). Seminars in Clinical Neuropsychiatry, 7, 293 -304.[Medline]
- Lolas, F. (1977) Brain polarization: behavioral and therapeutic effects. Biological Psychiatry, 12, 37-47.[Medline]
- Nitsche, M. A., Liebetanz, D., Antal, A., et al (2003) Modulation of cortical excitability by weak direct current stimulation - technical, safety and functional aspects. Supplementum Clinical Neurophysiology, 56, 255 -276.
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