What is postpartum psychosis? The mental health condition is at the center of the Lindsay Clancy trial​What is postpartum psychosis? The mental health condition is at the center of the Lindsay Clancy trial 

 Lindsay Clancy’s lawyers say a rare mental health condition caused her to kill her three children. So what is postpartum psychosis, and why is it so difficult to diagnose and treat? NBC News’ Erika Edwards reports.   ​​Lindsay Clancy’s lawyers say a rare mental health condition caused her to kill her three children. So what is postpartum psychosis, and why is it so difficult to diagnose and treat? NBC News’ Erika Edwards reports.