Light therapy may ease postpartum depression

OB/GYN News, Oct 15, 2002 by Sherry Boschert

YOKOHAMA, JAPAN -- The first randomized trial of bright white light therapy for postpartum depression found that it helped, but was no better than red light placebo, Dr. Maria Corral said at the 12th World Congress of Psychiatry.

Postpartum depression improved in all 18 women randomized to 8 weeks of daily half-hour sessions sitting in front of a light box. The depression lifted regardless of whether the boxes emitted 10,000 W of bright white light or 600 W of filtered red light, said Dr. Corral of the University of British Columbia, Vancouver.

Weekly scores on a modified Hamilton Depression Scale called the SIGH-SAD improved with treatment by an average of 40%. One-third of patients showed a 50% improvement, which would be considered a good clinical response in most trials of medications, she noted. Two patients had complete remission of depression. The study included only patients with mild to moderate depression that started postpartum.

Women with high scores on the Seasonal Pattern Assessment Questionnaire at the start of the study showed the greatest improvements--an average 56% reduction in depression scores, compared with a 30% reduction in women whose scores suggested that they were less affected by seasonal changes.

Bright white light therapy, introduced in the 1980s to treat seasonal affective disorder, also has been used to treat premenstrual syndrome, bulimia, circadian rhythm disturbances, and nonseasonal depression, so investigators had hoped it might help with postpartum depression.

The fact that red light worked as well could mean that red light is biologically active, or that the gains could be due to placebo effects, Dr. Corral said at the meeting sponsored by the World Psychiatry Association.

The results also might be ascribed to having 30 minutes of quiet time in front of the light box each morning, free of other responsibilities. "They all said that this was very therapeutic," Dr. Corral said. Alternatively, the improvements simply may be part of the natural history of mild to moderate postpartum depression, she added.

Preliminary, uncontrolled trials of group therapy or estrogen replacement therapy have shown some promise, according to Dr. Anita Riecher-Rossler, the head of outpatient psychiatry at Kantonsspital, Basel, Switzerland.

A 4-year preliminary trial of group therapy for women with postpartum depression at the same institution proved promising enough that it will be studied in a randomized, controlled trial from 2003 to 2006, Dr. Maria Hofecker Fallahpour reported in a separate presentation in the same session.

Thirty-one of 46 women admitted to the group therapy program completed the 12 weekly, 90-minute group therapy sessions plus 1 couple's therapy session for women with a spouse or partner. Each group included six to nine women plus two therapists and focused on cognitive-behavioral techniques, education about motherhood, and planning to handle future activities and crises.

Depressive symptoms improved significantly with each week of therapy, Dr. Hofecker Fallahpour said. The women reported that their relationships with their children improved. Participants attended nearly all the sessions, "which is remarkable given the demands of motherhood," she said.

"Bad" relationships with spouses or partners reported by 23 women before the therapy did not improve, something that may need to be addressed more in the future, she added.

Half the women had started antidepressant therapy before entering the program, but depressive symptom scores declined regardless of whether the women were using antidepressants.