title: Structure and measurement of depression in youths: applying item response theory to clinical data.
abstract: Our goals in this article were to use item response theory (IRT) to assess the relation of depressive symptoms to the underlying dimension of depression and to demonstrate how IRT-based measurement strategies can yield more reliable data about depression severity than conventional symptom counts. Participants were 3,403 children and adolescents from 12 contributing clinical and nonclinical samples; all participants had received the Kiddie Schedule of Affective Disorders and Schizophrenia for School-Aged Children. Results revealed that some symptoms reflected higher levels of depression and were more discriminating than others. Furthermore, use of IRT-based information about symptom severity and discriminability in the measurement of depression severity was shown to reduce measurement error and increase measurement fidelity.
authors.affiliation: Department of Psychology and Human Development, Vanderbilt University, Peabody MSC 512, 230 Appleton Place, Nashville, TN 37203, USA. david.cole@vanderbilt.edu
authors.forename: David A
authors.initials: DA
authors.lastname: Cole
authors.forename: Li
authors.initials: L
authors.lastname: Cai
authors.forename: Nina C
authors.initials: NC
authors.lastname: Martin
authors.forename: Robert L
authors.initials: RL
authors.lastname: Findling
authors.forename: Eric A
authors.initials: EA
authors.lastname: Youngstrom
authors.forename: Judy
authors.initials: J
authors.lastname: Garber
authors.forename: John F
authors.initials: JF
authors.lastname: Curry
authors.forename: Janet S
authors.initials: JS
authors.lastname: Hyde
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Essex
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Compas
authors.forename: Ian M
authors.initials: IM
authors.lastname: Goodyer
authors.forename: Paul
authors.initials: P
authors.lastname: Rohde
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Stark
authors.forename: Marcia J
authors.initials: MJ
authors.lastname: Slattery
authors.forename: Rex
authors.initials: R
authors.lastname: Forehand
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003863:Depression / Q000175:diagnosis* / Q000523:psychology; D003866:Depressive Disorder / Q000175:diagnosis* / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D015233:Models, Statistical; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics / Q000706:statistics & numerical data*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index