Dual Diagnosis and Alcohol/Nicotine Use Disorders: Native American and White Hospital Patients in 3 States.

Introduction: Nationally, mental illness prevalence is comparable among Native Americans and Whites experiencing alcohol and nicotine use disorders. However, authors are concerned that mental illness in Native Americans with substance use disorders may be disparately underdiagnosed in medical settings. For 3 states with large Native American populations, this study compares the prevalence of mental illness diagnoses among Native Americans and Whites hospitalized with alcohol/nicotine use disorders.

Methods: In 2021, hospital discharge data were used to compare non-Hispanic Native Americans with non-Hispanic Whites in Arizona and New Mexico (2016-2018) and (regardless of Hispanic ethnicity) Native Americans with Whites in Oklahoma (2016-2017). Differences in any mental illness, mood, and anxiety diagnoses were assessed using multilevel regressions (adjusted for demographics, payor, comorbidities, facility). Adjusted predicted probabilities were constructed.

Results: Among alcohol-related discharges, probabilities of non-Hispanic Native Americans and non-Hispanic Whites receiving any mental illness diagnoses in Arizona were 18.0% (95% CI=16.1, 19.9) and 36.8% (95% CI=34.1, 39.5), respectively; in New Mexico, they were 24.5% (95% CI=20.7, 28.3) and 43.4% (95% CI=38.7, 48.1). Oklahoma's probabilities for Native Americans and Whites were 30.7% (95% CI=27.4, 34.0) and 36.8% (95% CI=33.5, 40.2), respectively. Among nicotine-related discharges, any mental illness diagnosis probabilities for non-Hispanic Native Americans and non-Hispanic Whites in Arizona were 21.2% (95% CI=18.9, 23.5) and 33.1% (95% CI=30.3, 35.9), respectively; in New Mexico, they were 25.9% (95% CI=22.7, 29.1) and 37.4% (95% CI=33.8, 40.9). Oklahoma's probabilities for Native Americans and Whites were 27.3% (95% CI=25.1, 29.6) and 30.2% (95% CI=28.0, 32.4), respectively. Mood and anxiety diagnoses were also significantly lower for non-Hispanic Native Americans in Arizona/New Mexico and Native Americans in Oklahoma.

Conclusions: Findings suggest disparate underdiagnosis of mental illness among Native Americans hospitalized with alcohol/nicotine use disorders in the examined states.