Depression during pregnancy (antenatal depression) is relatively common, affecting about 10% of women. While there is a growing body of literature supporting the reproductive safety of certain antidepressants, our understanding of how these psychotropic medications affect the developing fetus remains incomplete. For this reason, antidepressants are typically avoided during pregnancy; thus, there is a clear need for effective non-pharmacologic treatments for women at high risk for antenatal depression.
In an open trial, 16 pregnant patients with DSM-IV major depression were treated with 3 to 5 weeks of light therapy. Subjects were exposed to daily bright light therapy (10,000 LUX) for 60 minutes, beginning within 10 minutes of awakening. After 3 weeks, mean depression ratings on the Hamilton Depression Rating Scale, Seasonal Affective Disorders Version (SIGH-SAD) improved by 49%, with half of the women experiencing a complete remission (SIGH-SAD <8). Of the seven patients who elected to continue treatment for 5 weeks, further benefit was seen through 5 weeks of treatment. Light therapy was well tolerated, with only two patients developing nausea, which responded to a reduction in duration of light exposure. There was no evidence of adverse effects of light therapy on pregnancy. Among the 14 women followed after completion of the study, depression returned in ten: during pregnancy in four, within 3 months of delivery in four, and later in two.
This pilot study demonstrates that morning bright light therapy may be an effective and well-tolerated non-pharmacologic option for women with antenatal depression. As compared to patients with winter depression, women in this study appeared to have a more gradual improvement in depressive symptoms; however, after 3 weeks of treatment remission rates were similar. What remains to be determined is the ideal duration of treatment, as significant relapse rates were observed in those patients who terminated treatment.
Ruta Nonacs, MD PhD