Since the introduction of the DSM-III there exists a renewed interest in the use of diagnostic criteria as a means of delineating classification-categories. In an explorative study, using the criteria for Major Depressive Disorder (a DSM-III category) and for Childhood Depression according to Weinberg, the importance of choice of criteria and their scoring conditions is demonstrated. Slight differences between the two constructs were found to result in selecting quite different clinical populations. Suggestions are made for how to choose and to score criteria to improve the reliability and validity of the childhood depression classification-category.