Comorbidity of empirically based syndromes in matched general population and clinical samples.

Comorbidity of deviance on eight empirically based syndromes was compared in matched general population and clinical samples of 2,705 children aged 4-18, using a bidirectional formula to avoid confounding effects of differential base rates. Syndromes were assessed via parent ratings on the CBCL, teacher ratings on the TRF, and self ratings on the YSR. Significantly higher comorbidity rates were obtained for clinical than general population samples for all 28 pairings of CBCL syndromes, 15 pairings of TRF syndromes, and 22 pairings of YSR syndromes. Bidirectional comorbidity rates for empirically based syndromes were compared to pairings of comparable DSM-III diagnoses.