It has been suggested that D2 receptor agonists commonly used postpartum for the physiological suppression of lactation, such as bromocriptine and cabergoline, may increase the risk of illness onset or relapse in women where there is a predisposition for or history of schizophrenia, bipolar disorder or postpartum psychosis. This is based on two lines of reasoning: current models of psychosis assume episodes are triggered by dysregulation of brain dopaminergic activity and treated by medications that universally have D2 receptor antagonist properties; and limited research suggesting these agents may be associated with psychotic episodes in vulnerable individuals outside of the postpartum period.

The aim of this study was to examine whether D2 agonists trigger psychosis in previously well mothers, or psychotic relapse or exacerbation of symptoms in mothers with known psychotic illnesses, when used to suppress lactation during the early postpartum period.

Materials and Methods
A systematic review of the literature was undertaken of electronic databases, including: MEDLINE, EMBASE and PsychINFO from 1950 to 2015 using keywords.

Eight case reports, three case series and a pharmacovigilance survey were identified.

Whilst D2 receptor agonists appear to increase the risk of triggering psychosis in previously well mothers and those previously diagnosed with schizophrenia, bipolar disorder and postpartum psychosis, bromocriptine appears to pose a much greater risk than cabergoline. When considering the use of pharmacological agents to suppress lactation, physicians should carefully screen patients for a history of psychosis and consider alternatives to moderate this risk.