The Parent Questionnaire (scale A2), the Teacher Questionnaire (scale
B2) by Rutter, and the Children's Depression Inventory (CDI) were vali
dated using KOC-analysis. The material wets collected from an epidemio
logical study of a normal population of 5664 8-9 year-old children. Th
e screening results were compared with the corresponding parent, teach
er, and child (DISC) interviews. In addition to this traditional way o
f valida.ting the combined interview, results from all three interview
s were also used. We found that the Teacher Questionnaire scale B2 was
the most valid, and had the best overall :power to discriminate psych
iatric disturbances. The Teacher Questionnaire (scale B2) may be recom
mended when screening child psychiatric disturbances. The Parent Quest
ionnaire (scale A2) was also found to be a valid instrument. Our resul
ts do not support the use of CDI as a sole screening instrument of psy
chiatric disturbances in children.