be decisive. These depend on expert laboratory methods. It is important that the clinical study is also 'state-of-the-art'– that scientists understand the complexity of these psychoses, and the need for multiple and reliable information sources to establish the diagnosis. Other non-organic postpartum psychoses It is much less common to encounter other acute psychoses in the puerperium. Psychogenic psychosis This is the name given to a psychosis whose theme, onset and course are all related to an extremely stressful event. The psychotic symptom is usually a delusion. Over 50 cases have been described, but usually in unusual circumstances, such as abortion or adoption, or in fathers at the time of the birth of one of their children. They are occasionally seen after normal childbirth. Paranoid and schizophrenic psychoses These are so uncommon in the puerperium that it seems reasonable to regard them as sporadic events, not puerperal complications. Early postpartum stupor Brief states of stupor have rarely been described in the first few hours or days after the birth. They are similar to parturient delirium and stupor, which are among the psychiatric disorders of childbirth. Organic postpartum psychoses There are at least a dozen organic (neuropsychiatric) psychoses that can present in pregnancy or soon after childbirth. The clinical picture is usually delirium – a global disturbance of cognition, affecting consciousness, attention, comprehension, perception and memory – but amnesic syndromes and a mania-like state also occur. The two most recent were described in 1980 and 2010, and it is quite likely that others will be described. Organic psychoses, especially those due to infection, may be more common in nations with high parturient morbidity. Infective delirium The most common organic postpartum psychosis is infective delirium. This was mentioned by Hippocrates: there are 8 cases of puerperal or post-abortion sepsis among the 17 women in the 1st and 3rd books of epidemics, all complicated by delirium. In Europe and North America the foundation of the metropolitan maternity hospitals, together with instrumental deliveries and the practice of attending necropsies, led to epidemics of streptococcal puerperal fever, resulting in maternal mortality rates up to 10%. The peak was about 1870, after which antisepsis and asepsis gradually brought them under control. These severe infections were often complicated by delirium, but it was not until the nosological advances of Chaslin and Bonhöffer that they could be distinguished from other causes of postpartum psychosis. Infective delirium hardly ever starts