Does a parent-report measure of behavioral problems enhance prediction of conversion to psychosis in clinical high-risk adolescents?

Recent research on risk for psychosis has focused on youth who manifest subclinical signs that are often associated with the prodrome to psychosis. Standardized measures of prodromal symptoms have been shown to significantly enhance prediction of risk for conversion to an Axis I psychotic disorder. In the present study, a widely used parent-report measure of behavioral problems, the Child Behavior Checklist (CBCL) was administered to examine the clinical and diagnostic utility of the measure as an adjunctive screening instrument in the identification of at-risk youth. The CBCL, the Structured Interview for Prodromal Syndromes (SIPS), and other diagnostic measures were administered at baseline and at one year follow-up assessments to adolescents (n=41) at clinical high-risk for the development of a psychotic disorder. Analyses were conducted to compare the 14 at-risk adolescents who subsequently converted to psychosis to the 27 who did not. Conversion to psychosis was defined as conversion to an Axis I psychotic disorder or affective disorder with psychotic features. Consistent with expectations, at one year follow-up, compared to the Non-Converted participants, the Converted participants manifested significantly higher scores on the prodromal symptom scales of the SIPS. There were, however, no differences in CBCL social and behavioral ratings as a function of conversion status. It is concluded that the CBCL does not show promise as an alternative or adjunctive predictor of conversion to psychosis in at-risk adolescents.