Four-year follow-up of an epidemiological sample.

In this 4-year follow-up of behavioral/emotional problems in an epidemiological sample of 1,200 children originally aged 4 to 12 years assessed with the Achenbach Child Behavior Checklist (CBCL), high stability in the level of CBCL total problem scores was found. Stability of problem behavior was equally substantial for ages 4 to 12 and both sexes. Aggressive and other externalizing behaviors showed the highest stability. Even in children as young as 4 to 5 years, aggressive and attentional problems showed considerable stability. The results of the present study were informative with respect to methodology in indicating clearly that employing a mailing survey for obtaining parent reports on behavioral/emotional problems resulted in the selective exclusion of a group of especially problematic children who were recovered when parents were interviewed at home.