Paediatricscommon
A 29-year-old woman brings her six-week-old first baby to the general practice for his immunisations. Asked how she is, she says she has felt flat since about the second week, cries most days and has stopped answering her friends' messages. She lies awake even when the baby sleeps, finds no pleasure in him and has lost 4 kg because she is not eating. Her partner says she has been like this for a month. She denies any thought of harming herself or the baby and has no unusual beliefs about him. Which one of the following best accounts for her presentation?