It's a severe form of mental illness that occurs after having a baby, and can happen ‘out of the blue’ to many women.
It's called Postpartum Psychosis and last year, it was highlighted in Eastenders when Stacey was diagnosed with the condition, shortly after giving birth to her son Arthur.
The illness can be frightening and shocking for both the woman experiencing it and her family. But it IS treatable.
Hannah Bisset had Postpartum Psychosis with her first baby. She now works for the charity Action on Postpartum Psychosis as a Peer Supporter: