• Citing postpartum illness, woman who killed her children seeks clemency
  
• CNN.com: Postpartum depression: More than the 'baby blues'
   
• Beyond the Baby Blues
  from Nursing Spectrum
  
• Postpartum depression blamed for suicide
  from Medserv

From the WebMD website:

• Postpartum Depression
   
• Postpartum Depression
  For the one in 10 new dads whose partners suffer from postpartum depression, it can be a frightening and lonely experience.

 A very technical presentation of hypotheses: 

• The Functions of Postpartum Depression
  Edward H. Hagen--Department of Anthropology