Dr Lewin is right that puerperal psychoses are of special interest in the context of acute and transient psychoses. To our knowledge there is consensus that post-partum disorders are not distinct nosological entities (Reference BrockingtonBrockington, 2004; Reference Riecher-Rössler, Rohde, Riecher-Rössler and SteinerRiecher-Rössler & Rohde, 2005) with neither ‘post-partum depression’ nor ‘post-partum psychosis’ having specific aetiology. ‘Giving birth to a child with all its biological and psychosocial consequences seems to act as a major stressor, which – within a general vulnerability–stress–model – can trigger the outbreak of all classical disorders in predisposed women’ (Reference Riecher-Rössler, Rohde, Riecher-Rössler and SteinerRiecher-Rössler & Rohde, 2005). Hence it is evident that the situation after delivery can be typical for triggering acute and transient psychosis.

Re-evaluation of our own sample of 61 women (Reference Rohde and MarnerosRohde & Marneros, 1993) with first onset of psychosis after delivery showed that according to ICD–10 criteria 18 (29.5%) should be classified as having acute and transient psychosis (Reference Rohde, Marneros, Marneros and AngstRohde & Marneros, 2000); all other diagnostic categories were also present (schizoaffective and affective disorders, schizophrenic and organic psychoses). In our sample the frequency of acute and transient psychoses was much higher than expected from the general prevalence. This might be a reason for the frequent observation that puerperal psychoses are mainly very acute, short episodes with a ‘colourful’ psychopathology and good prognosis.

Considering the few available studies we conclude that in the post-partum period acute and transient psychoses represent a disorder that is different from other psychiatric disorders but is part of a psychotic continuum.