White-Light Therapy Improves Depressive Symptoms in Cancer Survivors
NEW YORK — Light therapy has been found to decrease depressive symptoms and normalize circadian rhythms among cancer survivors.
Researchers from the Icahn School of Medicine at Mount Sinai, Northwestern University in Chicago, the University of Iowa, University of California in San Diego, and Reykjavik University in Iceland randomly divided 54 cancer survivors into a bright white light or a dim red light group. Participants were provided with a light box and asked to use it for 30 minutes every morning for four weeks.
Depressive symptoms and circadian activity rhythms were measured before, during and three months after completing the light exposures to determine the effectiveness of the therapy. The researchers reported that patients exposed to the bright white light experienced improvement in depressive symptoms, while those exposed to the dim red light experienced no change in symptoms.
"Depressive symptoms are common among cancer survivors even years after treatment has ended," said professor Heiddis Valdimarsdottir of the Icahn School. "This interferes with overall quality of life and puts survivors at risk for poor outcomes including death."
Most patients face some degree of depression, anxiety and fear when cancer becomes part of their lives. According to the American Cancer Society, one in four people with cancer have clinical depression.
"Our findings suggest light therapy, a rather noninvasive therapy, may provide an innovative way to decrease depression among cancer survivors," said professor William Redd, also of the Icahn School.
- Also known as PBM, an event in which nonionizing optical radiation in the visible and near-infrared (NIR) spectral range is absorbed by endogenous chromophores to elicit photo-physical and photo-chemical events at various biological scales. Photobiomodulation therapy (PBMT) is a form of light therapy based on the concepts of PBM and uses light in the visible and NIR spectra to cause physiological changes and clinical benefits.
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