The purpose of this study is to determine whether morning bright light therapy is an effective treatment for major depression during pregnancy compared with low-intensity placebo light therapy, when administered 60 minutes daily for 5 weeks.

Affective disorder during pregnancy is a common and severe condition, associated with a higher risk for prenatal complications, preterm delivery, a higher rate of surgical birth and vaginal operative delivery. Depressed pregnant women are at risk for inadequate nutrition, poor weight gain, increased use of nicotine, drugs and alcohol, and failure to obtain adequate prenatal care, as well as poor mother-child attachment. Their infants have a higher risk for low birth weight, a higher rate of admission to neonatal intensive care, and cognitive, emotional and behavioural disturbances.Treatment of antepartum depression requires careful judgement to minimise risk to the foetus. Pharmacological treatment is an option, but all antidepressants cross the placenta, and both practitioners and patients are concerned about possible teratogenicity, pre- and perinatal adverse effects for the infant, as well as negative effects on long-term development. Thus, psychiatric medication use for depression in pregnancy may also pose an excess risk of preterm delivery and withdrawal symptoms in the newborn. Treatment of depression during pregnancy that is efficacious, reliable, safe, and with minor side effects is an urgent unmet clinical need. Light therapy may provide this somatic, non-pharmaceutical alternative. It is well established as the treatment of choice for Seasonal Affective Disorder (SAD), and there is a growing data base for response in nonseasonal major depression. Two promising pilot studies led to the present randomised, double-blind, placebo-controlled trial of 5 weeks daily morning bright light therapy (1h, 7000 lux white) compared with low-intensity placebo light therapy (1h, 70 lux red).

Inclusion Criteria:

• German-speaking
• Medically healthy with normal ocular function
• Pregnancy 4 through 32 weeks gestation based on first trimester ultrasound
• DSM-IV diagnosis of major depressive disorder
• SIGH-ADS [Structured Interview Guide for the Hamilton Depression Rating Scale (HAMD) with Atypical Depression Supplement] score of >20
• Able to provide informed consent
• Preferably untreated; exception when on antidepressant for more than 3 months without any improvement, keeping medication constant during the study

Exclusion Criteria:

• DSM-IV diagnoses of bipolar 1 or 2 disorder or any psychotic episode
• Substance abuse within the last 6 months
• Primary anxiety disorder
• Recent history of suicide attempt (6 months)
• Delayed sleep phase disorder or hypersomnia with habitual sleep onset later than 1 a.m. or wakening later than 9 a.m.
• Obstetrical care or medications for medical disorders which might confound treatment results
• Fetal malformations and intrauterine fetal death