First-person accounts of depression almost always emphasize the extent to which depression departs from what is -- for most of us -- 'everyday experience'. It is often described as akin to inhabiting a different world, a suffocating, alien realm that is isolated from the rest
of social reality. On the basis of a very substantial body of testimony, it seems that depression is not simply a matter of certain unpleasant emotions being heightened while other emotions are diminished. The phenomenological changes that the depressed person undergoes are somehow more profound
than that. They involve a qualitative shift in the overall structure of experience, encompassing self, agency, the body, temporal experience, interpersonal relations, and the sense of being rooted in a world. Many sufferers add that this shift or some aspect of it is indescribable, ineffable,
and that the various metaphors they appeal to are ultimately inadequate to the task. Furthermore, some state that an inability to communicate the experience of depression exacerbates the sense of alienation that is already so central to it. When we turn to diagnostic manuals, matters are no
clearer; skeletal descriptions of the various symptoms that are together sufficient for one or another diagnosis do nothing to further illuminate the kinds of phenomenological change that patients struggle to describe. Hence an aim of this special issue is to draw upon work in philosophy and
other disciplines in order to cast light upon poorly understood experiences that are associated (but, most likely, not exclusively associated) with depression.