First-episode acute and transient psychotic disorder in Latvia: a 6-year follow-up study.

BACKGROUND: Acute and transient psychotic disorder (ATPD; F23, ICD-10) is an acute, short-lived psychosis, which has variable prevalence worldwide and has not been extensively studied.

AIMS: To explore the first episode of ATPD in patients in Latvia by describing the clinical features, analyzing the longitudinal changes of diagnosis and associated socio-demographic characteristics.

MATERIAL AND METHODS: Retrospective chart review of all first-time hospitalized patients fulfilling the ICD-10 criteria for ATPD treated at the Riga Centre of Psychiatry and Addiction Disorders, Latvia, during a 3-year period. Patients were followed-up and assessed using standardized instruments.

RESULTS: During a 3-year period, 294 patients were first-time hospitalized with a ATPD diagnosis; 54% were women. The average age at first psychotic episode was 35.7 ± 12.3 years for women, and 30.0 ± 10.8 years for men (P < 0.0001). Over an average of 5.6 years follow-up period, 51% of patients were not re-hospitalized. Later diagnosis was changed to schizophrenia in 73% of the re-hospitalized patients, mostly within the first 2 years of illness. The overall stability rate of ATPD diagnosis reached 58%. Typical polymorphic symptomatology, abrupt onset (i.e. within 48 h), less frequent anxiety, but more frequent hallucinations were observed in ATPD patients that later developed schizophrenia (P < 0.05). Stressful life events in the 6 months prior to the first episode were found in 44% of patients.

CONCLUSIONS: Combining these assessments from first-episode ATPD patients in Latvia, with data from other countries may help to predict the development of disease and provide the possible basis for potential changes to ICD-11.