One or two in a thousand may not sound like many until you know that in 2004 there were just over 4.1 million births in the United States. This translates to 4,100 to 8,200 women who experience postpartum psychosis per year. Given the rates of suicide and infanticide related to postpartum psychosis, this estimates at risk over 300 infants killed and more than 400 mothers committing suicide because of this illness each year in the US alone.