We surveyed 160 recent studies of adolescent depression (publication dates ranged from March 1996 to August 2000) and identified 33 different diagnostic and symptom measurement instruments being used by various investigators. We also found that more than one in three of the studies measuring depressive symptom severity in adolescents relied on instruments designed for use with adults. We then reviewed in detail the design features and psychometric properties of the 12 instruments most commonly used in studies of adolescent depression and attempted to characterize their strengths and weaknesses. Our main conclusions are as follows: Too many different instruments are being used by investigators, presumably due to a lack of consensus as to which are the most valid and reliable tools. Instruments designed for use in adults and never validated in adolescent populations are frequently used with no evidence for their developmental sensitivity. Many studies are using instruments that demonstrate substantial weaknesses in validity and/or reliability. The need for a parsimonious, easily administered, valid, and reliable tool(s) to diagnose and measure symptom severity in adolescent depression has not yet been met.