Antidepressant effects of the sleep/wake cycle phase advance. Preliminary report

Five patients with endogenous depression were asked to participate in a phase-advance procedure consisting in advancing by 5 h the time schedule of the major external synchronizers such as light/dark, sleep/wake, meal time and social activity cycles. Clinical and biological parameters were observed throughout this 2-week process which followed one night of partial sleep deprivation. All patients improved with partial sleep deprivation and four of the five showed continuing remission during the phase-advance process. The antidepressant effects of the phase-advance process are discussed in light of different chronobiological models for depression.