A 6-day combined wake and light therapy trial for unipolar depression

Abstract

Background: There are a dozen studies on double or triple chronotherapy in depression (sleep deprivation [wake therapy] + light therapy + sleep advance/stabilization). We investigated efficacy and feasibility of a modified triple chronotherapy protocol.

Methods: Thirty-five hospitalized patients with moderately severe non-seasonal depressive disorder, mostly free from antidepressants, underwent a 6-day protocol consisting of partial sleep deprivation late in the second half of the night (from 4:00 to 8:00) in a light therapy room (blue-enhanced white light increased hourly from 600→1300→2200→2800 lx) alternating with recovery nights with morning light treatment from 7:00 to 8:00. Patients were randomized to wear glasses with no filter (clear, N = 19) or filtering blue wavelength (orange-appearance, light intensity diminution by ∼70%, N = 16) during the treatments. Sleep was targeted to be shifted at least 1 h earlier. Depression was scored using HDRS-17 (Hamilton Depression Rating Scale) and BDI-II (Beck Depression Inventory-II) - before and after the 6-days treatment, HDRS-6-SR - daily, and visual analogue scales (VAS) for mood and energy - several times every day.

Results: Depression levels significantly declined following the first night and after 6-days treatment, with no difference between white and orange lights. Nevertheless, some superiority of white light emerged with respect to response rate (mood VAS), immediate effect during the 4-h treatment sessions (energy VAS), and expected treatment outcomes. All patients successfully advanced bedtime/wake-up (by 30-40 minutes) and resisted naps during daytime.

Limitations: Relatively small sample size.

Conclusions: The modified triple chronotherapy was well tolerated and improved depression. Light spectrum/intensity plays some role in the response.

Keywords: Blue-enhanced light; Chronotherapy; Partial sleep deprivation; Unipolar depression.