Postpartum Depression Linked To Bottlefeeding?

I thought this article was very interesting and wondered if mothers who had experienced postpartum depression would comment as to whether they breastfed or bottle fed, and comment their thoughts on this theory.

It makes sense to me. It proposes that not breastfeeding tells your body that your infant has died and that cause postpartum depression.

http://www.albany.edu/news/images/GGallupbottlefeeding.pdf