Illness representations in depression.

BACKGROUND AND OBJECTIVES Illness representations in physical health problems have been studied extensively using the Self-regulation Model (SRM) focusing on five dimensions of illness beliefs (identity, consequences, causes, timeline and control, or cure). Associations have been found between beliefs about illness and a range of health outcomes. This study aimed to examine models of depression, to assess whether the five dimensions of the SRM are relevant, to compare depression models with those for physical illness, and to examine the psychometric properties of the Illness Perception Questionnaire (IPQ) when used with depression. DESIGN AND METHOD A sample of 101 women either currently depressed or with a history of depression was asked to write about their experiences of physical sickness and depression. Their responses were analysed in terms of the dimensions of beliefs expressed and the two experiences were compared. The IPQ was also administered to assess the women's perceptions of depression. RESULTS The women used the same five dimensions of illness as identified in the SRM in describing both their experience of depression and physical sickness. There was evidence of some consistency across the models of the two illnesses in terms of their content and structure. The IPQ was a reliable measure for depressed experiences and discriminated between women who were currently depressed or not. Comparing the women's descriptions of their depression with their IPQ scores showed some relationships between their responses on the two different measures, at least for the consequences and cause dimensions. CONCLUSION The SRM model and associated methodology may provide an appropriate framework to further explore illness representations in depression. Problems inherent in the study of illness models in depression including the influence of mood on the model are described. Applications of this research area to the understanding of treatment preferences and adherence to treatment in mood disorders are discussed.