Most, but not all cases of postpartum psychosis are episodes of bipolar disorder.
They may be due to other psychiatric conditions or other medical conditions causing delirium. These are what psychiatrists call “mixed mood states” (part of bipolar disorder) and which can result in big fluctuations in how a person is feeling and behaving. Women seem to be particularly prone to these states after having a baby.
It is not known why women, especially those with a history of bipolar disorder, either in themselves or other family members, are particularly vulnerable to getting unwell at this time. Many theories abound. Some women are particularly vulnerable to the mental effects of sudden changes in hormone levels (this seems to set off an underlying mood disorder). Sleep deprivation may also be an important trigger.
Treatment and outcome
Fortunately there is good news – most women with postpartum psychosis respond well to treatment with medication (yes, medication is needed) and to intensive nursing. Unfortunately, there is currently only one inpatient Mothers and Babies Service in New Zealand – this service is in Christchurch – although some smaller centres will also admit baby with mother. Intensive home nursing is sometimes possible but usually women suffering from postpartum psychosis need admission to hospital.
Full recovery usually occurs but future relapses – both after having a baby and at other times – are possible (see Bipolar disorder).