Short-Term Course And Outcome Of Acute And Transient Psychotic Disorders: Differences From Other Types Of Psychosis With Acute Onset

Background: The category of acute and transient psychotic disorders' (ATPDs) appeared in the ICD-10 Classification of Mental and Behavioural Disorders (ICD-10), but its distinctive features remain uncertain.Aim: To examine the course and outcome of ATPDs, pointing out differences from other types of psychosis.Methods: A one-year follow-up investigation of patients enrolled at the former World Health Organization (WHO) Centre for Research and Training in Mental Health in Aarhus (Denmark) for the WHO collaborative study on acute psychoses.Results: Of 91 patients aged 15-60years presenting with acute psychosis, 47 (51.6%) were diagnosed with ATPD, and it occurred more commonly in females; yet, the other acute psychoses featured mainly mood disorders and affected equally both genders. After 1year, the ATPD diagnosis did not change in 28 cases (59.6%); the remaining developed either affective psychoses (27.7%), or schizophrenia and schizoaffective disorder (12.8%). Nearly, all patients with unchanged diagnosis of ATPD enjoyed full recovery, while those with other types of acute psychosis had significantly higher rates of recurrence or incomplete remission. Duration of illness within 4weeks and stressful events in the 3months before symptom onset predicted 1-year favourable clinical outcome for acute psychoses.Conclusion: Although ATPDs fared better over the short-term than other acute psychoses, their diagnostic stability is relatively low.