[영문]OBJECTIVE: American-Indian adolescents have high rates of addiction and mental health problems but low rates of service use. The gap between service need and use appears to be even larger than the known gap for the general population, and few of the services are provided by specialists. This study examined receipt of treatment by American-Indian youths for addictions or mental health problems, the service provider who first identified a problem and sent a youth to treatment, and the extent to which the provider's knowledge and assessment predicted variance in service actions. METHOD:S: A sample of 401 American-Indian youths (196 from an urban area and 205 from a reservation) aged 12 to 19 years was first interviewed in person in 2001. A total of 188 of the youths' treatment providers were then interviewed. RESULTS: Structural equation modeling showed that 30 percent of the variance in addictions or mental health services provided to youths was predicted by the provider's assessment of the youth's mental health, the provider's resource knowledge, and provider type. CONCLUSION:S: The results demonstrate that professional, informal, and traditional providers play a pivotal role in providing treatment services offered to American-Indian youths and that these providers were more likely to identify a youth's problems and to offer and refer services when the provider knew more about community resources for the youth and about the youth's personal and environmental problems.