The purpose of the present study was to assess the validity of the Beck Depression Inventory (BDI), the MMPI Depression scale (MMPI-D), and the Rorschach Depression Index (DEPI) in measuring adolescent depression. Retroactive charts of 118 hospitalized adolescents were divided into depressed (n=66) and nondepressed (n=52) groups, based on the psychiatric diagnosis. Results indicated significant differences between the means of the two groups on the BDI (p<0.00001) and the MMPI-D scale (p<0.0001), establishing concurrent validity for these measures of depression. Correlation coefficients among the three measures of depression indicated a significant relationship between the BDI and the MMPI-D scale (p<0.01), again supporting the concurrent validity of these instruments. Predictive utility was determined for each of the three instruments individually and in combination, with results indicating that the BDI and MMPI-D scales alone and in combination significantly discriminated depressed from nondepressed adolescents. The MMPI-D scale alone was the most accurate measure in classifying the participants into their respective groups. The DEPI was not established as a valid predictor of adolescent depression. (C) 1996 The Association for Professionals in Services for Adolescents