High rates of bipolar in postnatal depression

The study of 10,000 mothers screened for PND four to six weeks after birth showed 14% had positive scores on the Edinburgh Postnatal Depression Scale (EPDS). Of these, 68.5% had unipolar disorders, almost all of which were recurrent major depression, and 22.6% had bipolar depression. In women with both unipolar and bipolar depression, around 80% also had comorbid anxiety disorders.

The authors said bipolar disorder was likely underestimated because the EPDS does not screen for the hypomanic/manic phase.