No latent period in the onset of bipolar affective puerperal psychosis. Heron et al. (2007) AWMH 10, 79-81

Prompt recognition of postpartum psychosis (PP) is important for effective treatment of the illness.  This study investigates the timing of onset of PP, questioning the long held belief that there is a ‘latent’ (symptom-free) period before the onset of illness around 3-5 days after delivery.  Previous studies, relying on clinical case notes, rather than interviewing mothers themselves, could only identify when episodes had become severe enough to require clinical attention. 

In contrast, for this study 101 women recruited through APP were questioned about the onset of clear psychiatric symptoms occurring in the postpartum period.  Of these women, 85 reported symptoms occurring during the first week after delivery, including 22 whose symptoms began on day 1.  In addition, women in the study reported many more minor ‘symptoms’ and emotional changes that occurred earlier in the postpartum period or even in late pregnancy.  These results do not support the concept of a ‘latent’ period immediately following delivery.

Careful monitoring to detect signs of impending illness in women at risk should occur at an early stage in the postpartum.  The study has implications the identification of hormones which may be involved in PP.