Light therapy is often used for seasonal affective disorder (SAD), in which people fall into depression during certain times of the year, usually in fall and winter. The depressive disorders may stem from time changes and adjustment to daylight. The patient is exposed to a bright light through a light therapy box that provides light similar to outdoor light. The therapy has been found to be useful for other depressive disorders as well.
Gloomy
Light therapy suppresses melatonin, a hormone that regulates biorhythms and alters circadian rhythms, which maintains a 24-hour pattern for the body. The bright light reduces or controls symptoms that cause the depression, according to the Mayo Clinic. The light therapy provides more light than found outdoors in the fall or winter. This often works well for patients who get depressed on dark or gloomy days, especially in the winter season.
Various Disorders
Aside from using it for SAD, light therapy has been used by people with major depression, obsessive-compulsive disorders, postpartum depression and sleep disorders. The therapy, which is still being studied, is also used for people with jet lag and shift-work difficulties.
Bipolar Disorder
A study by researchers at the University of Pittsburgh, reported in the December 2007 issue of "Bipolar Disorders," found that light-box therapy at midday improved depressive symptoms in women with bipolar disorder. Four of nine women receiving the therapy for 15 to 60 minutes a day for up to six weeks had complete relief. Two other women had partial relief, based on scores in a depression guide used by the researchers. Bipolar disorder, also known as manic depression, produces mood swings from being manic or overexcited into a severe depressed state. Researchers theorized that light treatment at midday can suppress symptoms of mania by keeping circadian rhythms steady. Morning light therapy may destabilize the rhythms. One woman in the study showed full improvement from treatment in the morning.
Considerations
People with different forms of depressions may choose light therapy for a variety of reasons. The person may not want to take antidepressants or cannot tolerate the side effects of the medication. The medication may also not work. People with depression who do not want conventional therapy or lack access to mental health services have also used it.
Sessions
Patients can either purchase their own light therapy boxes or use them in offices. They sit in front of the box and take in the light, but not directly. Some therapy sessions are successful when used at the beginning of the morning. Others, however, have been shown to be effective at midday, depending on the type of depression. Patients who suffer from SAD begin therapy as fall starts when they know their symptoms will begin. Sessions may start out with 15 minutes of use, and gradually move on to 30 minutes or hours.
