How Does Light Therapy Help Depression?
Since the beginning of time, people have realized the healing power of light. We feel rejuvenated when we’re in sunshine, and we literally whither in the dark. In the early eighties, researchers discovered that specialized bright light (20 times brighter than normal indoor light), was the most effective treatment for winter depression. Now tests are confirming that this light is effective for non-seasonal depression as well.
It turns out that light is more than psychological. Light actually produces hormones and neurotransmitters that affect our mood and well being. One of these hormones, serotonin, is thought to be a major factor in depression. One recent study that was reprinted in The Lancet, showed that bright light significantly increased serotonin levels, while dark or cloudy days caused serotonin to plummet.
Dozens of clinical, placebo controlled studies have been done using light therapy to treat depression. These studies confirm that light is not only as effective as other methods, but it causes no long-term side effects. Additionally, people responded within a week to light instead of several weeks with medications, and different medication trials were needed before an effective regimen was found.
Researchers report that depression is closely tied to circadian rhythm disorders because almost all depression sufferers have sleep problems and feel worse at a particular time of day as well as in the winter. When treated with bright light, these problems improved significantly. Because bright light quickly corrects the circadian imbalance in depression, patients respond to light within a week verses months with antidepressant medications.
The fact that depression is circadian related is further evidenced through a new treatment known as wake therapy. Researchers believe that depression sufferers have unresponsive body clocks. Wake therapy awakens the patient several hours early, which blocks any feedback signals to the body clock when it is most active. This effect ‘reboots’ the body clock, causing it to revert to an active day cycle. With wake therapy, symptoms of depression disappear almost immediately. Wake therapy is only necessary for the first night if used with bright light each successive morning.
This revelation on circadian rhythms and depression has led researchers to conclude, "These common experiences suggest that disruptions in biological clocks may be both cause and consequence of disturbed moods."-- Michael Smolensky, The Body Clock Guide to Better Health
Specialized bright light is recommended by the American Psychiatric Association (APA) as well as the American Acadamy of Sleep Medicine. In January 2004, the Cochrane Medical Library issued the Cochrane Review of all depression related light therapy studies, and recommends light therapy for depression treatment. (Cochrane is considered by the medical industry to be the gold standard in medical review.)
Light Treatment for Nonseasonal Depression: Speed, Efficacy, and Combined Treatment
The Journal of Affective Disorders
Daniel F. Kripke
Bright light can be combined with standard therapies for treating nonseasonal depressions and appears synergistic
Bright Light Augments Antidepressant Effects of Medication and Wake Therapy
Archives of General Psychiatry
Richard T. Loving, R.N., D.N.Sc., Daniel F. Kripke, M.D., and Stephen R. Shuchter, MD
Inpatient studies have suggested that bright light therapy can be used to sustain the antidepressant effects of wake therapy (sleep depravation). ...excellent responses to wake therapy can be maintained if the patient receives bright light treatments every morning thereafter.
Wake Therapy an Effective Treatment for Depression
Scientists discover missing key to treating depression with wake therapy. How wake therapy was discovered. When combined with bright light, wake therapy may be an effective antidepressant modality.
Wake Therapy News Release
PR Healthwire News Release
San Diego, CA: Doctors have known for decades that sleep deprivation immediately reversed the effects of depression, but for only a day or so. Now doctors can extend the antidepressant effects of sleep deprivation (now called wake therapy*) by adding bright light treatments.