Whether high-dose omega-3 fatty acids supplement would be an effective treatment in patients with major depressive disorder during pregnancy and breast-feeding.

Inclusion Criteria:

• Eligible participants were pregnant women, aged 18 to 40 years, with major depressive disorder onset between their 16th week (second trimester) and 32nd week (third trimester) of gestation at the Department of Obstetrics.

Exclusion Criteria:

• Subjects were excluded with a DSM-IV diagnosis of bipolar disorders, psychotic disorders, substance abuse or dependence for at least 3 months, or any Axis-II diagnosis of borderline or antisocial personality disorder.