Objective: The Children's Depression Rating Scale-Revised (CDRS-R) is a valid instrument for the assessment of depressive symptoms in youth, but this measure is yet to be validated in Korea. Thus, the present study aimed to evaluate the validity of the Korean version of the CDRS-R and to determine its factor structures.
Methods: This study included 66 youths between 12 and 17 years of age who participated as part of an ongoing study investigating biomarkers of the antidepressant response and suicidal events in depressed youth. At baseline, the participants were assessed using the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime version (K-SADS-PL), CDRS-R, Children's Depression Inventory (CDI), Beck Depression Inventory (BDI), Clinical Global Impressions-Severity (CGI-S), Children's Global Assessment Scale (CGAS), and Child Behavior Checklist (CBCL). Based on their diagnosis, each participant was assessed either five (major depressive disorder [MDD], n = 36) or two (non-MDD, n = 30) more times with the CDRS-R, CDI, BDI, CGI-S, and CGAS; thus, 306 assessments were included in the final analyses of the present study. Pearson's r and Cronbach's α values were used to determine validity and internal consistency, and exploratory factor analysis was performed to determine the factor structures of the Korean version of the CDRS-R.
Results: The CDRS-R score was significantly correlated with scores on the K-SADS-PL depression subscale (r = 0.93, p < 0.01), CDI (r = 0.86, p < 0.01), BDI (r = 0.85, p < 0.01), CGI-S (r = 0.84, p < 0.01), and CGAS (r = -0.86, p < 0.01), indicating that this measure has strong criterion validity. In addition, the high correlation of the CDRS-R with the depression subscale of the CBCL (r = 0.67, p < 0.01) and lower correlations with the subscales of the CBCL that assess delinquent behavior, aggressive behavior, and externalizing problem support the discriminant validity of this instrument (rs ≤ 0.50, p < 0.01). Internal consistency was high, as evidenced by a Cronbach's α of 0.91, and the exploratory factor analysis revealed that the Korean version of the CDRS-R comprised three factors as follows: subjective depressed mood, daily functional impairment, and observed depressive affect. These factors differed from those used in previous studies, which were performed with the English version of the CDRS-R.
Conclusions: This study of the Korean version of the CDRS-R provides initial promising data regarding its criterion validity, discriminant validity, internal consistency, and factor structures. These properties were significantly strong, which suggests that the Korean version of the CDRS-R is a valid and reliable instrument for the assessment of depressive symptoms in youth.
Keywords: CDRS-R; factor structures; reliability; validity.