Light therapy may help women with bipolar disorder

NEW YORK (Reuters Health) - Bright light therapy can relieve depression in some women with bipolar disorder, a study shows.

Bright light treatment started out as a way to relieve winter depression, but it has since been shown to be effective for seasonal and non-seasonal major depression. It could also benefit people with bipolar disorder, in which moods swing from depression to mania, note the authors of the report in the medical journal Bipolar Disorders.

To see what "dose" of bright light might be best, Dr. Dorothy Sit, of University of Pittsburgh Medical Center, Pennsylvania, and colleagues conducted a small study with nine women in the depression phase of bipolar disorder who were unresponsive to conventional treatments.

The women were given light boxes and used them for 15, 30, and 45 minutes daily, each for 2-week periods. Four patients used them in the morning and five at midday.

Of the four subjects treated with morning light, three developed mixed states; that is, "symptoms of depression and mania that occur at the same time -- racing thoughts, irritability, sleeplessness, anxiety and low mood," Sit explained in a press release.

The patients in the midday group had a more stable response, so the researchers changed the time of light exposure to midday for all the participants.

Overall, six of the nine patients had some degree of benefit from bright light therapy, once the timing and duration of treatment had been adjusted to individual responses.

Sit's team concludes that women with bipolar disease "are highly sensitive to morning bright light treatment." They recommend that patients who do not respond to conventional treatment should begin "with a brief duration (15 minutes) of midday light."

SOURCE: Bipolar Disorders, December 2007.