Antidepressant effects of sleep deprivation and phototherapy

In contrast to drugs, sleep deprivation and phototherapy rapidly induce depressive remissions, which are rapidly reversible. These characteristics make them useful tools for prospective, longitudinal studies of the psychobiology of depression. It seems likely that discovery of the mechanism of action of these two antidepressant procedures would increase our understanding of the pathogenesis of depression and lead to novel, rapidly acting pharmacological treatments. Further progress in this direction depends on careful delineation of which conditions of the procedures are necessary for their antidepressant efficacy and identification and pharmacological manipulation of biological correlates of the procedures that may be relevant to their mechanism of action. Analogies between the two procedures suggest that similar mechanisms may be involved in both.