Ethnic Differences in Adolescent Mental Health Problems: Examining Early Risk Factors and Deviant Peer Affiliation

Using life-course longitudinal data from the Christchurch Health and Development Study (CHDS), we examined ethnic differences in rates of psychiatric disorder among New Zealand adolescents, comparing New Zealand Māori to their European peers. The CHDS includes a large birth cohort of New Zealand children who have been regularly assessed throughout childhood, adolescence, and adulthood. Ethnicity (New Zealand Māori vs. non-Māori) was assessed at age 14 years. Internalizing and externalizing disorders were assessed at age 15, 16, and 18 years. A diverse range of risk factors were included to test if differences in mental health difficulties were explained by greater exposure to early life-course challenges. We found significant differences in rates of mental disorder during adolescence between New Zealand Māori and non-Māori, but these differences were largely explained by early developmental challenges and adolescent peer affiliations. Differences across the two ethnic groups in rates of internalizing disorders were explained by the increased exposure amongst Māori to socioeconomic disadvantage during childhood, while differences in externalizing disorders were explained by greater exposure amongst Māori to childhood family adversity and deviant peer affiliation during adolescence. The findings point to the significant influence of cumulative early life-course risk factors in accounting for the ethnic differences between Māori and non-Māori in the development of adolescent internalizing and externalizing disorders.