The global prevalence of depression is increasing, along with rates of depression-associated disability and mortality, rendering depressive disorders a major public health issue. Chronotherapy involves a variety of strategies that control exposure to environmental stimuli that influence the biological clock, such as sleep deprivation (SD) or wake therapy (WT), sleep phase advance (SPA), and light and dark therapy (LT, DT). The purpose of this Evidence-Based Practice (EBP) paper is to answer PICOT questions by a review the effectiveness of chronotherapeutics interventions on depressive symptoms with depression and the depressive episode in the course of bipolar disorder. Early studies suggested the effectiveness of LT, SD, and SPA, more recent research has revealed differences in the efficacy of single and combined interventions involving both chronotherapeutic and pharmacological components. This therapy reduced dura-tion of hospitalization, improvement recovery, and reduced for changes in drug prescriptions.