McKenzie et al (Reference McKenzie, Whitley and Weich2002) illustrate how emerging conceptions of social capital can help psychiatric researchers study links between social context and the prevalence, course and outcome of psychiatric conditions. Two further considerations deserve a place in this discussion. First, the premise that social capital is ‘a property of groups rather than of individuals’ (Reference McKenzie, Whitley and WeichMcKenzie et al, 2002: p. 280) does not enjoy an unqualified consensus. Work by Princeton sociologist Alejandro Portes (Reference Portes1998) summarises the case against insisting that social capital be treated as a group attribute. A more individualist approach draws attention to the important distinction between the social relationships that allow a person to make claims on resources held by others and the resources themselves. A family's struggle to find a job for a recently hospitalised relative may be eased somewhat when they live in a community with trusting social relationships, but this effect is more limited in a resource-poor community. (For example, Portes (Reference Portes2000) found that alleged effects of social capital on the academic achievement of immigrant children in the USA are drastically reduced when proper controls are used for parental socio-economic status.)

Second, McKenzie et al note that high social capital may be found in bad groups, such as the Mafia, and in homogeneous groups that restrict the freedom of members or exclude outsiders and minorities. This analysis of negative consequences can be expanded by an individual-oriented discussion of a dilemma familiar to clinicians working with socially marginal populations. Individuals may indulge in apparently irrational spending sprees to buy food, drugs or alcohol for companions because these allow them to make future claims for reciprocity when times are lean (Reference DordickDordick, 1997). The resulting mutual obligations can make it difficult for even a highly motivated person to enter (or re-enter) the social mainstream because he or she is vulnerable to criticism for breaking ranks with compatriots (Reference BourgoisBourgois, 1995) or to claims on cash resources saved to facilitate an exit (for tuition, a new apartment, etc.). Programmes serving these populations need to devise strategies to help patients manage this dynamic aspect of social capital, even as they focus on recovery.