BACKGROUND Previous studies have suggested that the risk for psychosis, especially affective psychosis, is highly increased during the first 30 days after delivery. The aim of our study was to replicate these findings.
METHOD Linking The Danish Medical Birth Register and The Danish Psychiatric Central Register from 1 January 1973 to 31 December 1993 revealed 1253 admissions diagnosed as psychosis within 91 days after delivery. The admission rate after delivery was compared with the admission rate among non-puerperal women in the general Danish female population.
RESULTS The relative risk of all admissions was only slightly increased, RR = 1.09 (95% CI 1.03-1.16). The admission rate concerning first admissions was highly increased, RR = 3.21 (95% CI 2.96-3.49) whereas the admission rate concerning readmissions was reduced, RR = 0.66 (95% CI 0.61-0.72).
CONCLUSIONS Childbirth is a strong risk factor for first admission with psychosis, but the risk may be less increased than previously assumed.