Beyond the Kraepelinian dichotomy: acute and transient psychotic disorders and the necessity for clinical differentiation.

The concept of acute and transient psychoses is, together with that of schizoaffective disorders, a challenge by the Kraepelinian dichotomy. Although these conditions have some similarities to schizophrenia, they differ significantly from schizophrenia regarding onset, duration, prognosis, gender and premorbid adaptation. They show some similarities with bipolar disorders. They do not fit into the dichotomous concept.