Concordance of acute and transient psychoses and cycloid psychoses

We prospectively investigated a sample of 42 patients with acute and transient psychotic disorder (ATPD) as defined by the 10th revision of the International Classification of Diseases (ICD-10; F23) to determine the clinical and demographic features of this entity and its relationship to cycloid psychoses.

During a 5-year period, all in-patients with ATPD were identified. We systematically evaluated demographic and clinical features and carried out follow-up investigations on average 2 years after the index episode, using standardised instruments.

We found 42 cases of ATPD (4.1%) among 1,036 patients treated for psychotic disorders or a major affective episode. There was a marked female preponderance in ATPD (79%). Fifty-five percent of cases concurrently met the criteria of cycloid psychosis according to Perris and Brockington [in Perris C, Struwe G, Jansson B (eds): Biological Psychiatry. Amsterdam, Elsevier, 1981, pp 447-450]. There was no difference in gender distribution between cycloid and non-cycloid ATPD. As expected, abrupt onset and polymorphic features were significantly more common in cycloid than in non- cycloid ATPD. At follow-up, patients with cycloid ATPD showed less persistent alterations and better social functioning.

ATPD as defined by ICD-10 is a heterogeneous category. A diagnosis of cycloid psychosis is made in half of the cases of ATPD, and in these cases, the prognosis is more favourable.