Abstract
The aims of this study were to investigate the reliability of ICD‐10 and DC 0–3 in the diagnostic classification of mental health problems in 1½ ‐year‐old children from the general population. The reliability study was conducted as a part of an epidemiological survey of psychopathology in 1½ ‐year‐old children from the general population. In this survey, the children were assessed and diagnosed according to the ICD‐10 and the DC 0–3 after a 2‐hr session including standardized and clinical methods and videorecordings. The case records and video material of 18 children were rediagnosed by the three child psychiatrists, who had diagnosed children in the epidemiological survey. In general, the reliability in diagnostic classification of mental health problems in 1½‐year‐old children was improved with the DC 0–3 compared to the ICD‐10. In the classification of psychopathology at Axis I, the interrater reliability and test‐retest reliability kappas were 0.66 and 0.57, respectively, with the ICD‐10, and 0.72 and 0.74, respectively, with the DC 0–3. The reliability of the classification of relationship disturbances at Axis II with the DC 0–3 was high, corresponding to κ = 1. A high agreement among raters in the differentiation between psychopathology and normal variations was found. Given experienced clinicians and standardized assessment methods, it is possible to reliably identify and diagnose psychopathology in 1½‐year‐old children from the general population.