The CBCL DSM-oriented somatic problems scale: measurement invariance across sex, informant, ethnicity, and time

Abstract Background The DSM-oriented Somatic Problems scale (SOM) of the Child Behavior Checklist (CBCL) comprises seven items assessing somatic concerns in adolescents. Despite its widespread use, evidence for its psychometric properties remains limited. Methods This study examined the factor structure, reliability, and measurement invariance across sex, informant, and ethnicity using ABCD Wave 1 data ( N = 9,987), and longitudinal measurement invariance across a six-year developmental window at three assessment points using mother-reported data ( N = 1,799). Results Results supported the theorized one-factor structure of the SOM and demonstrated acceptable reliability. Evidence of approximate measurement invariance, up to the scalar level, was established across sex and informant, and evidence approaching scalar invariance was found for ethnicity. Longitudinal metric and scalar invariance were supported across waves, scalar invariance providing a sufficient basis for interpreting longitudinal SOM scores as reflecting genuine developmental change in somatic symptom burden. Conclusions These findings support the SOM as a psychometrically sound measure suitable for group comparisons, longitudinal research, and population-level monitoring of somatic symptoms in adolescence.