Sleep and major depressive disorder: a review of non-pharmacological chronotherapeutic treatments for unipolar depression.

Depression is a significant public health issue, made worse by the absence of response to antidepressant medications by many patients. Given the high degree of overlap between sleep and circadian complaints and depression, chronotherapies are a promising avenue for novel, effective, and fast-acting treatments for depression. A critical literature review was conducted of bright light therapy (BLT) as a treatment for unipolar depression. Additionally, a separate critical literature review was also conducted of several promising, non-pharmacological, combination chronotherapeutic treatments, including BLT, sleep deprivation/wake therapy, and sleep phase advance. Results of BLT as a treatment for depression are encouraging, especially when used as an adjunct to antidepressant medications. It may also be desirable in special populations, such as geriatric and perinatal patients. Overall, results from combination chronotherapies are encouraging, though none has strong empirical support. Combining chronotherapies is an avenue of treatment which should be further explored.