Phototherapy (Bright Light Therapy)
While recognized as an effective treatment in seasonal affective disorder (SAD), there is also evidence that light therapy is therapeutic in non-SADs.[67,68] Studies have examined the therapeutic role of light therapy both as monotherapy for MDD and as an adjunct to pharmacotherapy. Data suggest that light therapy in either role may be therapeutic, but recent systematic reviews have not shown this conclusively.[67–69] Studies that used morning light treatment and targeted sleep deprivation responders showed better efficacy data. In an attempt to review the safety of light therapy for depression, Lam et al. retrospectively studied suicidality in 191 nonpregnant patients with SAD who received light therapy for their depression. Patients were rated using the Structured Interview Guide for the Hamilton Depression Rating Scale (HDRS), Seasonal Affective Disorder Version (SIGH-SAD), which includes an eight-item supplemental scale for 'atypical' depressive symptoms, and the authors focused on one suicidality item, scored from 0–4, describing a range from feelings of worthlessness to attempts at suicide. This study found that 45% (85 of 191) of patients had a reduction in the suicide item (p < 0.001), while 3% (six of 191) of patients reported a higher suicide score after treatment and no patients reported a suicide attempt. Overall, 67% (128 of 191) patients were rated as treatment responders, and SIGH-SAD scores decreased by a mean of 56 ± 24%.
Given the low risk to the fetus, two studies have looked at the efficacy of light therapy in treating depression in pregnancy (Table 1). Oren et al. used a prospective, open trial with an A–B–A design (pretreatment – active treatment – post-treatment) to explore the effect of 60 min of 10,000-lux morning light exposure on 16 women meeting Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria for MDD. The primary outcome measure was an augmented version of the 21-item HDRS SIGH-SAD. The mean age of women in this study was 34 years, all patients were Caucasian, and women were on average 23 weeks pregnant. They found that after 3 weeks of treatment, the average reduction in SIGH-SAD was 49%, with 50% (eight of 16) of patients experiencing a reduction in SIGH-SAD of 50% or greater. For patients that underwent 5 weeks of treatment, 57% (four of seven) patients had at least 50% reduction in SIGH-SAD with a final absolute score less than 8, crossing a common benchmark for complete remission. While these results are encouraging, the study design lacked a control condition.
Extending these findings, the same group proceeded to study 10 women in a randomized trial that included a placebo condition. Women with an average age of 32.1 years and from 8–32 weeks pregnant were recruited through media and local physician referrals. All women met DSM-IV criteria for MDD. The trial included a lead in of 1 week during which all women were instructed to wake up 30 min earlier than they were accustomed to, in an effort to control for the impact of altering the sleep cycle. Subjects were then randomized to receive 60-min daily treatments of either 7000 lux active bright light or 500 lux dim placebo bright light within 10 min of rising for 5 weeks. Daily phone logs monitored compliance. Subjects with a partial response to active light at the end of 5 weeks, defined by a 25–49% decrease in SIGH-SAD, were instructed to increase duration of exposure to 75 min for 5 additional weeks, while placebo nonresponders could choose a 5-week trial of active therapy. After 5 weeks, there was a nonsignificant trend in improvement in the active group compared to the placebo group. The overall small size of the study may have contributed to inability to detect a group difference.
While available research is not conclusive, light therapy remains a promising treatment for MDD. However, there are not enough data to be able to conclusively recommend this as an evidence-based treatment for depression during pregnancy. If psychotherapy or antidepressants are not an option for a particular patient with a mild-to-moderate MDE, a course of light therapy may be of benefit, with no documented risk to the fetus, and perhaps specifically for women with seasonal exacerbation of mood symptoms. Patients should be carefully screened for bipolar disorder prior to prescribing light therapy given the risk of emergent hypomania. Guidelines for prescribing light therapy are summarized in Table 3.
Women's Health. 2010;6(4):565-576. © 2010 Future Medicine Ltd.
Cite this: Unipolar Depression During Pregnancy: Nonpharmacologic Treatment Options - Medscape - Jul 01, 2010.