Why mental disorders flourish and wither: Extending the theory of ecological niches

Why do some mental illnesses emerge in certain times and places and later disappear? Because it integrates a wide array of social processes and relies on a strong epistemological position, Hacking's theory of ecological niches constitutes the most comprehensive and ambitious attempt to answer this question. However, this theory lacks a convincing definition of its research object (“transient mental illnesses”), a conceptualization of how individuals would “fall ill” as well as a solid methodological framework to form case studies. This article addresses these issues in order to propose an extended theory of ecological niches.