Light Therapy Is Safe, Effective Treatment for Depression in Pregnancy

One in 10 pregnant women experience depression with severe risks, and depression during pregnancy is associated with higher risks for complications as well as postpartum depression. Yet treating depression during pregnancy raises concerns for maternal well-being and fetus well-being alike, requiring clinicians to constantly balance the benefits of psychopharmacological agents for women while minimizing risks to their fetuses.

Since light therapy has been proven to be safe and effective for seasonal affective disorder, and some data show promise for the treatment of nonseasonal major depression, Dr Anna Wirz-Justice, emeritus professor and research fellow at the Centre for Chronobiology at the Psychiatric Hospital of the University of Basel, and colleagues sought to determine if this modality could be useful in treating pregnant women. The researchers conducted a randomized, double-blind, placebo-controlled trial of light therapy with a parallel design and duration of 5 weeks. The study included 27 pregnant women with nonseasonal major depressive disorder, with 16 randomized to the bright light group and 11 in the placebo group. There was no clinical or sociodemographic differences found between the placebo and active treatment groups.

Participants were instructed to maintain their normal sleep time (ie, bedtimes and wake times) routines. Within 10 minutes of waking, the women were supposed to sit at a specified distance in front of the lightbox for 60 minutes to receive an active dose of 7000 lux white light (4.2 x 10⁵lux.min) or a placebo dose of 70 lux red light (3.0 x 10³lux.min). Wirz-Justice and colleagues found no difference in compliance between the groups based on the participants’ logs.

Using two different efficacy measures, Structured Interview Guide for the Hamilton Depression Rating Scale with Atypical Depression Supplement (SIGH-ADS) and Hamilton Depression Rating Scale (HDRS), the researchers noted more improvement in the active treatment group versus the placebo group after 5 weeks. Specifically, they saw 15.6 and 11.2 drops in the light therapy group versus 11.9 and 7.4 point drops in the placebo group in the SIGH-ADS and HDRS, respectively. Since the majority of placebo-controlled studies for pharmaceuticals show a difference of 2 points on the HDRS, the researchers felt their 4-point drop was impressive and important. Somatic symptoms also appeared to improve in the light therapy group. Sleep did not appear to be affected by the light treatment in either group.

The authors caution that there is no data to date to verify that light therapy incurs minimal risk to the fetus, but suggest that 1 hour of light therapy is similar to 1 hour of outdoor light. Wirz-Justice and associates further noted light therapy’s good adverse effect profile, which adds to the attractiveness of light therapy as a potential solution for depression in pregnancy.

“Light therapy is perceived as ‘natural’ and therefore appeals to pregnant women, since most of them wish to avoid medication,” stated Wirz-Justice and colleagues. “It could provide a long-sought therapeutic modality suited to this vulnerable population.”

More Information

• Mayo Clinic: Light Therapy

• Light Therapy for Depression During Pregnancy

Related Content

• Resource Center: Postpartum Depression

• Special Deliveries Apparently Predispose to Postnatal Depression

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Reference

Wirz-Justice A, Bader A, Frisch U, et al. A randomized, double-blind, placebo-controlled study of light therapy for antepartum depression.  J Clin Psychiatry. Epub April 5, 2011.