Ethnic and sex differences in suicide rates relative to major depression in the United States.

OBJECTIVE: Suicide rates differ between ethnic groups in the United States. Since suicide is commonly associated with a mood disorder, the authors compared suicide rates relative to depression rates in five ethnic groups in the United States.
METHOD: Rates of major depression were generated from the Epidemiologic Catchment Area study and the Hispanic Health and Nutrition Epidemiologic Survey. Sociodemographic effects were determined by examining depression rates for respondents who were separated or divorced, earning low incomes, or not working for pay. The survey data were analyzed with age and sex standardization to generate 1-year prevalence rates of major depression. The depression rates of the different ethnic groups were compared and were examined in relation to suicide rates.
RESULTS: The 1-year prevalence rates of major depression were 3.6% for whites, 3.5% for blacks, 2.8% for Mexican Americans, 2.5% for Cuban Americans, and 6.9% for Puerto Ricans. Compared to the rate for whites, the rate of depression was significantly higher in Puerto Ricans and significantly lower in Mexican Americans. Relative to the depression rates, the annual suicide rates were higher for males than for females. Mexican American and Puerto Rican males had lower relative suicide rates than white males.
CONCLUSIONS: Identifying reasons for differences in suicide rates relative to depression among ethnic groups and between males and females may suggest interventions to reduce suicide rates. Some possibilities are that depression differs in form or severity or that unidentified factors protect against suicide in different subgroups.