Assessment and classification of psychopathology in epidemiological research of children 0-3 years of age: a review of the literature.

The research of psychopathology in children 0-3 years of age is dominated by clinical case studies and theoretical reflections, and epidemiological studies are few. This paper reviews methods to assess and classify psychopathology in children 0-3 years old in an epidemiological context. Diagnostic assessments of children 0-3 years of age are based on information from different sources and investigation of several domains of mental functioning, and the rapid developmental changes and the relationship context are taken into account. The reviewed literature shows a range of methods to assess and classify psychopathology in children 0-3 years of age: screening instruments with established psychometric properties, such as the Child Behaviour Checklist (CBCL) and the Checklist for Autism in Toddlers (CHAT), and methods of in-depth assessment known from both clinical practice and research: developmental tests, such as the Bayley Scales, and relationship assessments, such as the Early Relational Assessment (ERA). The classification of psychopathology in young children can be approved by the Diagnostic Classification 0-3. The reliability and validity of DC 0-3 have not yet been established, but preliminary results seem promising. The demands made on diagnostic assessment procedures in epidemiological research of children 0-3 years of age can be met by a combination of well-established research instruments, such as the CBCL, with in-depth clinical assessment procedures, such as the Bayley Scales and the ERA, and diagnostic classification by DC 0-3.