Lo-LIGHT Therapy Lamps Found Effective
in Clinical Studies on Depression


Light Therapy For SAD (Seasonal Affective Disorder)

The original study using bright light therapy for the treatment of seasonal depression, also known as Seasonal Affective Disorder [SAD] and Winter Depression, was conducted by Dr. A.J. Lewy in 1982. Since then it has been shown that depressive symptoms in people suffering from SAD could be relieved with bright light therapy. Unfortunately many people find the high intensity bright light therapy lamps uncomfortable to look at, and many retinal specialists expressed concerns that repeated exposure to high intensity light can contribute to a permanent loss of vision.

Low-intensity Lo-LIGHT lamps were developed to avoid discomfort from looking at high intensity light and to avoid the risk of eye damage from a bright light therapy lamp. The first study in which Lo-LIGHT therapy lamps effectively relieved symptoms of depression in winter depressives was also conducted by Dr. Lewy. That trial demonstrated that low intensity Lo-LIGHT lamps have the same influence on human circadian physiology as bright light therapy lamps.



sad woman

Lo-LIGHT Therapy for Non-Seasonal
Major Depression and Bipolar Depression

Lo-LIGHT lamps were used in the pioneering studies that found chronotherapy to be effective for the treatment of non-seasonal major depression and bipolar depression. Chronotherapy is a protocol using appropriately timed light therapy and sleep deprivation to regulate the internal body clock.

Studies using Lo-LIGHT lamps for the treatment of bipolar depression were published in several journals including the Journal of Clinical Psychiatry and JAMA Psychiatry. The Lo-LIGHT lamp was found to induce large phase shifts in the body clock of patients, which researchers showed correlated with the dramatic improvement and the alleviation of symptoms in a majority of the subjects.

The study using Lo-LIGHT lamps to treat bipolar depression published in JAMA Psychiatry claimed "repeated total sleep deprivation (TSD) and light therapy (LT) caused rapid and sustained antidepressant effects in a matter of hours or days" without side effects.

*(JAMA Psychiatry was formerly titled the Archives of General Psychiatry)

A study in the Journal of Clinical Psychiatry found most of the patients suffering from bipolar depression who received 1 week of treatment with chronotherapy {i.e. sleep deprivation and exposure to a Lo-LIGHT lamp}, remained symptom free for the entire 9-month follow-up period.

(For references to studies referred to in this section please use link to depression studies below)


The original study of chronotherapy used Lo-LIGHT therapy lamps in combination with an antidepressant medication to treat severe major depression. This study found rapid improvement and remission of symptoms in most patients. The researchers chose the safe low-intensity Lo-LIGHT lamps because of their concern that antidepressant medications and lithium make the retina more susceptible to light damage. In subsequent studies the researchers determined it was not necessary to include the antidepressant.
Studies on the treatment of depression with Lo-LIGHT lamps.