Ah, I see I didn't even address your question. I tend to believe there's meaning in "madness," that experiences like sz have an least some psychological or emotional or traumatic basis. I don't buy into a pure medical model, in other words.

But even I think that postpartum depression/psychosis are mostly biochemical. Your entire hormonal system is thrown into chaos by pregnancy, childbirth, nursing, etc. It would be surprising if some women didn't have "mental problems" in those circumstances.

I suppose the stress of becoming a mother might contribute, but you say you had this experience with your middle child. So I assume you had children before and after without having this reaction. So, who knows?