The four dimensions: a model for the social aetiology of psychosis.

Recently, there has been increasing focus on prevention of mental illness, early intervention and the promotion of mental health. The social determinants of health and public health approaches are considered key. Early intervention has focused on psychotic disorders but prevention has not. This may in part reflect the fact that public health planners do not have a clear model for how social determinants influence the risk of developing a psychotic illness. Drawing on biological, genetic and epidemiologic evidence regarding the relationship between social risk factors and psychosis, this paper outlines a conceptual framework for understanding how individual and ecological factors contribute and interact to modulate the risk of developing psychotic illness. The framework asserts that there are four dimensions: individual factors; ecological factors; the interaction between individual and ecological factors; and time. It may help those considering interventions to understand the multilevel and multifactorial effects of social factors on the aetiology of psychotic illness, to develop targeted strategies for the prevention of psychotic illness and serve as a template for the assessment of initiatives.