The third one, and why it is here on page two

This is here at the start because a woman in the middle of it will not reach the end of a course, and the people around her need to know what they are looking at.

Postpartum psychosis is not severe depression and it is not being very tired. It is rare. It usually begins in the first two weeks and often in the first few days. What it looks like: not sleeping at all for a night or more and not feeling tired with it, confusion or a sense that time or reality has gone strange, beliefs that other people around you say are not true and that very often involve the baby, hearing or seeing things others do not, mood that is unusually high or racing or swinging fast, and the feeling that the baby would be better off without you or that you must protect the baby from something that is not there.

If that is the picture, do not wait to see if it passes and do not wait for a routine appointment. Someone else should stay with you and with the baby. Contact emergency services or your local crisis route now. The standard is immediate assessment by a mental health service, and the UK guidance names four hours.

Women who have bipolar disorder, or who have had an episode of postpartum psychosis before, are the group at highest known risk. If that is you, say so to your midwife or your doctor in pregnancy rather than after.