Considering what some women endure, it's surprising that the figure isn't higher.
There are different levels of depression and different mixtures of reasons between the hormonal to the environmental, the effects vary enormously. It's got nothing to do with weakness or strength, it's a matter of hormones and environment, telling a depressed person to pull themselves together is probably like telling an exhausted person to stay bright eyed and bushy tailed
I think exhaustion is what pushes a lot of people to the brink, it's torture trying to function on an hours broken sleep, if you combine that with the stress of minding a baby, the stress on your relationship, a different lifestyle (culture shock), financial worries, remaining health issues from pregnancy/birth and hormone fluctuations, depression is probably a natural consequence for some people.
Everybody is different, we all react individually so depression is just one of a variety of responses. It seems like a common one. Personally I find myself being extremely aggressive with crazy mood swings while being happy most of the time so I think my hormones are slightly deranged (or making me that way
), some people on here sound disassociated and in denial, some people have anxiety problems....
We're all somewhere on a vast spectrum and all of it is a normal part of being human, it's sad to see some women on here feeling so ashamed of their perfectly normal life experiences because they happen not to fit into the fantasy which we are all supposed to falsely portray to the world.