I read with interest Mumford et al's (Reference Mumford, Minhas and Akhtar2000) paper on stress and psychiatric disorder in urban Rawalpindi. Their findings and explanations of a lower prevalence of common mental disorders in an urban area compared with a rural area of Pakistan (Reference Mumford, Saeed and AhmadMumford et al, 1997) need to be treated with caution.

Their study population is unrepresentative of the city as a whole. Although they studied an urban slum, strictly speaking, it is a relatively ‘prosperous’ urban slum. The assets and income of this population lie between the fourth and the richest quintile for the Pakistani population (Reference Gwatkin, Rustein and JohnsonGwatkin et al, 2000). The use of only male interviewers for female subjects in an orthodox society is also a source of potential bias and cannot be ignored. This was not the case in the rural study. Thus, their findings are unlikely to be generalisable to the urban population of Rawalpindi or other cities of Pakistan. A more plausible explanation for their findings is that financial prosperity together with strong and varied social networks might be associated with a lower prevalence of common mental disorders. Their study attempts to address one aspect of urbanisation due to rural migration, rather than looking at stress and psychiatric disorder in urban Rawalpindi.