DSM-IV BPD is a psychotic disorder with broad concordance with ATPD as defined by ICD-10. However, the DSM-IV time criteria for BPD may be too narrow. The group of acute psychotic disorders with good prognosis extends beyond the borders of BPD and includes a subgroup of DSM-IV schizophreniform disorder.

ATPD are not a sharply demarcated and unchanging nosological entity. Nevertheless, the present data support a delineation of ATPD as a diagnostic category with specific clinical features and with a usually favourable prognosis. Further research on the topic is necessary.

ATPD show a characteristic psychopathological picture consistent with earlier concepts such as cycloid psychoses and bouffée délirante. Nevertheless, psychopathology alone is not enough to establish ATPD as an independent nosological entity.

Acute and transient psychotic disorder (ATPD) is supposed to differ from schizophrenia, but little research has been done on the subject. In a prospective longitudinal case control study we compared all inpatients with ATPD (ICD-10 F23) treated at Halle University Hospital during a 5-year period with matched controls with "positive" schizophrenia (PS) and with mentally healthy controls. Followup investigations were performed at a mean of 2.2 years after the index episode or 8.2 years after the first episode. Female preponderance in ATPD was marked (78.6%). ATPD and PS patients were similar to each other (but different from healthy controls) in the prevalence of a "broken home" situation and a family history for mental disorders. Compared with PS patients, ATPD patients showed better premorbid social adaptation, and they more often displayed rapidly changing symptoms in the index episode and a negative life event preceding the episode. Despite comparable relapse rates, at followup ATPD patients showed better social adaptation, less psychological impairment, and better global functioning than PS patients. These data support the delineation of ATPD from schizophrenia.