Post-partum psychoses and the dexamethasone suppression test.

The hypothesis that post-partum psychoses are predominantly mixed affective disorders was tested by administering the dexamethasone suppression test (DST) to seven puerperal psychotics, six puerperal depressives and comparison groups of non-puerperal psychotic and depressed women. The hypothesis received support from the finding that two-third of the puerperal patients had positive DSTs versus one-third of similar non-puerperal patients. An 80% rate of positive DSTs in 19 normal women 5 days post-partum, however, suggested this was an invalid interpretation of this finding, particularly as the majority of these tests returned to normal when repeated several weeks later.