This study sought to better understand cultural processes related to mental health outcomes for youth who received school and clinic-based mental health services. It aimed to address gaps in the literature by : 1) examining whether symptom severity at initial interview differs by affinity to mainstream American culture and affinity to indigenous/alternative culture, 2) investigating the relationship between affinity to mainstream American culture and affinity to indigenous/alternative culture, symptom severity at first interview, and mental health outcomes, and 3) exploring whether treatment engagement moderates the relationship between symptom severity at initial interview and mental health outcomes. The study involved youth/parent/therapist survey data related to 234 adolescents (aged 12-18). Research instruments measured parent and youth socio-cultural variables, both parent and youth report of affinity to mainstream American culture and affinity to indigenous/alternative culture, symptom severity levels, treatment engagement, and mental health outcomes. Analyses were conducted in Mplus 6.0 and utilized multi-level path analyses. Results showed a negative association between affinity to American culture and symptom severity at first interview according to youth self-report and a positive association between parent affinity to indigenous/alternative culture and parent report of youth symptom severity at first interview. Findings showed that youth and parent reports of higher youth symptom severity at first interview predicted poorer mental health outcomes. Symptom severity at first interview also appeared to mediate the relationship between affinity to mainstream American culture/affinity to indigenous/alternative culture and mental health symptomatology outcomes for some models. Therapist report of parent and youth total engagement was not found to moderate the relationship between youth symptom severity at treatment outset and mental health outcomes at follow- up. Findings from this study inform efforts to develop culturally competent mental health interventions. By better understanding how individual and familial characteristics predict mental health trajectories, researchers and practitioners will be better equipped to improve the effectiveness of services for diverse youth populations. These analyses should be considered preliminary, as updates and revisions may take place, particularly after consideration of qualitative data and other variables not examined in the present study