Depression as a Disorder of Consciousness

First-person reports of Major Depressive Disorder reveal that when an individual becomes depressed a profound change or ‘shift’ to one’s conscious experience occurs. The depressed person reports that something fundamental to their experience has been disturbed or shifted; a change associated with the common but elusive claim that when depressed one finds oneself in a ‘different world’ detached from reality and other people. Existing attempts to utilise these phenomenological observations in a psychiatric context are challenged by the fact that this experiential ‘shift’ characteristic of depression appears mysterious and resists analysis in scientific terms. This paper offers a way out of this predicament. The hypothesis proposed is that when an individual becomes depressed, the individual departs from a state of ordinary wakeful consciousness and enters a distinctive global state of consciousness akin to dreaming and the psychedelic state. After unpacking and motivating this hypothesis in the context of research in consciousness science, I outline two of its important implications for the neurobiology of depression and psychedelic psychiatry. The upshot is a promising and conceptually well-motivated hypothesis about depression which is apt for empirical uptake and development.