Authors' reply

The assertion that chronic fatigue syndrome is a culture-bound syndrome of high-income Western countries may be largely based on the observation that ‘clinical descriptions of chronic fatigue syndrome, also known in some countries as myalgic encephalomyelitis, have arisen from a limited number of high-income countries in Northern Europe, North America and Oceania’. ¹ We aimed to examine the reasons for this particular observation: proving or disproving the above assertion was beyond the scope of our study. Without any pre-assumptions regarding the local validity of the construct of chronic fatigue syndrome, we used this ‘etic’ construct (originating from high-income Western countries) in Brazil in order to examine whether this foreign concept defines a similar proportion of individuals as ‘cases’. We found that, using the current Centers for Disease Control (CDC) case definition of chronic fatigue syndrome, similar proportions of primary care attendees were defined as cases in São Paulo and London. However, Brazilian doctors were unlikely to recognise and/or label such patients as cases.

In a way, we actually used Kleinman's ² formulation of the category fallacy as a research method in our study. That is, by imposing an alien diagnostic concept where its local validity is untested and unknown, we examined which component of this alien construct is not sanctioned by the local cultural context: the occurrence itself or the recognition/labelling. In Brazil, although unexplained fatigue as formulated by the Western medical community indeed does occur, ‘it is not sanctioned as a medical condition worthy of medical treatment, sick leave or sickness benefit, and it may be more likely to be considered as part of everyday adversity and less likely to be recognised as a medical disorder’. ¹

Furthermore, although Paralikar et al suggest that our paper lacked consideration of the cultural context, we actually discussed and interpreted these findings mostly in light of the sociocultural context. For example, based on previous studies and our own data, we discussed that sociocultural differences such as the degree of medicalisation of the population and awareness of chronic fatigue syndrome among the population and the medical professionals might have contributed to the current findings. ^1,3,4

We have not specifically addressed alternative local formulations for the problems resembling chronic fatigue syndrome in Brazil. However, our case vignette study using a typical history of the syndrome according to the CDC definition revealed that the most common diagnoses given by Brazilian doctors were psychological disorders, ⁴ hence providing some information regarding the question raised by Paralikar et al. In order to address this and other important questions, we have collected qualitative data through in-depth interviews of individuals with chronic fatigue in Brazil and these data are currently being analysed.

We agree with Paralikar et al that the pattern of recognition and labelling observed in Brazil is not a failing, since this pattern is probably due to the sociocultural context rather than to medical incompetence. Indeed, we never suggested it was a failure.

Finally, the study by de Fatima de Marinho de Souza et al ⁵ actually used the same questionnaire as our study: the Chalder Fatigue Questionnaire. We also used a more inclusive concept of chronic fatigue as operationalised by this questionnaire, namely unexplained chronic fatigue, as we additionally screened for medical causes. The prevalence of unexplained chronic fatigue was similar in the two settings.