"I had no idea that it was happening to me," recalls Rachelle Silver. The general practitioner had just given birth to her daughter Samara, the youngest of three children under four years old.
"I thought I was just exhausted," Silver says. "The overwhelming feeling was that I was failing, that this was something that I've always wanted, I've got a supportive family, three healthy children, why am I not coping?"
The 36-year-old struggled with "the most menial tasks", was irritable with others and crying on the edge of the bed at night as she tried to rock her newborn to sleep.