Thornicroft et al ^{Reference Thornicroft, Chatterji, Evans-Lacko, Gruber, Sampson and Aguilar-Gaxiola1} assume that ‘mental disorder’ is an entity essentially lying outside situation, society and culture, which is identifiable anywhere using a common (Western) methodology such as the Composite International Diagnostic Interview (CIDI). Biologically triumphalist studies like this simply have to be challenged, because once something – in this case, depression as a unitary pathological entity arising naturalistically anywhere in the world – is declared real, it becomes real in its consequences.

The authors cite at the outset the World Health Organization (WHO) claim that depression is the first or second most burdensome disease, disability-wise, in the world. To me this is perhaps the most bizarre statement to come out of a major medical institution in the modern era: more burdensome than AIDS or tuberculosis, which each take around 1.5 million lives per year, and with millions more disabled over the years? The disability-adjusted life-years metric (DALY) on which the WHO claim rests is epistemologically lamentable when applied in this way.

The CIDI is described by the WHO as a survey instrument produced for standard use across cultures. This does not mean it is valid. The authors concede that ‘no attempt was made to go beyond DSM-IV criteria to assess depression-equivalents that might be unique to specific countries’, and that ‘the reliability and validity of diagnoses made with the WMH CIDI may vary across countries’. This doesn't appear to deter the authors, yet it renders their conclusions risible.

Western psychiatric templates simply cannot generate a universally valid knowledge base, since they fail the core test of validity, which relates to the ‘nature of reality’ of subjects under study. Invalid approaches cannot be redeemed by ‘reliability’ – using a standard, reproducible method – since the very ground they stand on is unsound. ^{Reference Summerfield2} This is hardly surprising since, organic categories aside, diagnoses are merely descriptive constructions, conceptual devices, and are drawn up by us, not by nature. Ironically there is a WHO study, reported by Sir David Goldberg and colleagues, which showed that in 15 cities around the world those people recognised as depressed by doctors did no better (indeed they did slightly worse) than comparable others who were not so recognised. ^{Reference Goldberg, Privett, Ustun, Simon and Linden3}

Depression has no exact equivalent in non-Western cultures, not least because these do not share a Western ethnopsychology that defines ‘emotion’ as internal, often biological, unintentioned, distinct from cognition, and a feature of individuals rather than situations. ^{Reference Lutz, Kleinman and Good4} Here we see the Western psychological discourse setting out abroad to instruct, regulate and modernise, presenting contemporary Western mentality and ways of being a person as definitive anywhere. Why should this imperialism suit the rest of the world? ^{Reference Summerfield5}

Half the countries surveyed here were low-income ones. What is ‘mental health’ in the poverty-haunted, near-broken parts of the world? Thinking of my own country, Zimbabwe, how would invalid approaches distinguish between depression and situational distress? Does Africa need the category of Western depression at all, and does it need the marketing of antidepressants which will ride in on the back of papers like this in international psychiatric journals? I think not.