The Zero-to-Three diagnostic classification: A contribution to the validation of this classification from a sample of 85 under-threes

The goal of this article is to contribute to the validity of the Zero‐to‐Three diagnostic classification (DC: 0–3) by studying the range, the indices of consistency, the interjudge reliability, and the issue of comorbidity on Axis I. Eighty‐five consecutive children under three years of age and their families were assessed in six mental health centers with clinical interviews and developmental testing. Diagnoses on the five axes of the classification system were made after clinical consensus. The Task Force data record DC: 0–3 was completed for each subject. The use of the classification on a sample of 85 children showed good consistency between the different axes, moderate interjudge reliability, and a high percentage of associated diagnoses on Axis I. The DC: 0–3 appears to help the clinician catch the complexity of the clinical situation in planning the therapeutic strategy. However, the objectivity of the diagnostic criteria must be improved if this system is to be used in research settings. ©2003 Michigan Association for Infant Mental Health.