title: Short-term course and outcome of acute and transient psychotic disorders: Differences from other types of psychosis with acute onset.
abstract: 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.
  
  
  OBJECTIVE
  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 15-60 years 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 1 year, 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 4 weeks and stressful events in the 3 months before symptom onset predicted 1-year favourable clinical outcome for acute psychoses.
  
  
  CONCLUSIONS
  Although ATPDs fared better over the short-term than other acute psychoses, their diagnostic stability is relatively low.
authors.affiliation: Centre for Psychiatric Research, Aahus University Hospital, Risskov, Denmark.
authors.forename: Augusto C
authors.initials: AC
authors.lastname: Castagnini
authors.affiliation: Department of Organic Psychiatric Disorders and Emergency Ward, Aarhus University Hospital, Risskov, Denmark.
authors.forename: Povl
authors.initials: P
authors.lastname: Munk-Jørgensen
authors.affiliation: Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus University Hospital, Risskov, Denmark ABertelsen@dadlnet.dk.
authors.forename: Aksel
authors.initials: A
authors.lastname: Bertelsen
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D038801:International Classification of Diseases; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011618:Psychotic Disorders / Q000145:classification / Q000175:diagnosis / Q000628:therapy*; D014944:World Health Organization; D055815:Young Adult
keywords: Affective psychosis; DSM; ICD-10; acute and transient psychotic disorders; brief psychotic disorder