BACKGROUND We examine the dopamine receptor supersensitivity hypothesis of puerperal psychosis, and explore puerperal changes in the functional sensitivity of this receptor system.
METHOD Dopamine receptor sensitivity was estimated using growth hormone (GH) response to apomorphine challenge following delivery in 37 control women, and 11 deliveries in 10 women at 'high risk' of puerperal psychosis (previous history of puerperal affective or non-puerperal manic psychosis). Tests were on days 4 or 5, 11 or 12 and at six weeks postpartum.
RESULTS Three women developing puerperal psychosis had subsensitive GH responsiveness on day 4. GH response to 67 challenge tests (in control and 'high risk' women) increased between days 4 or 5 and six weeks postpartum (P < 0.05). GH response at six weeks correlated with free thyroxine levels (P < 0.01).
CONCLUSIONS These three cases do not support the stated hypothesis. Hypothalamic dopamine receptor sensitivity increases during the puerperium; thyroxine might influence this.