Is there immune dysfunction in depressive disorders?

The hypotheses that psychological disorders result in disturbed immune function, and that such dysfunction, in turn, predisposes the individual to later physical illness, underpin the infant field of 'psychoimmunology'. Despite its short history the discipline has attracted considerable criticism. For example, in a British Medical Journal editorial, Denman (1986) stated that 'little (evidence) suggests that immune reactions are appreciably altered in depressive illnesses' but expressed his principal concern when he concluded 'even if one were to accept that depressive illnesses are associated with perturbed lymphocyte responses, there is sparse evidence that the changes matter'. Similarly, in response to a 1987 Lancet editorial titled 'Depression, stress and immunity', Hall (1987) claimed that 'the effect of psychological factors on the immune response is always marginal and inconsequential and usually undetectable'. We believe that critical examination of the available data should dissuade research workers from abandoning the field prematurely, especially with regard to depressive disorders. The conclusions of other recent reviews have expressed cautious support for the claim that a significant association between immune dysfunction and depression has been established (Calabrese el al. 1987; Perez & Farrant, 1988; O'Donnell et al. 1988) although some remain sceptical (King & Cooper, 1989). All these reviews attempt to avoid the impression that psychoimmunology is merely 'an unholy alliance between the fringes of psychology and immunology' (Hall, 1987).