Co-occurrence of Alcohol Use Disorder and Symptoms of Drug Use Disorder Among Immigrant Groups Living in both Sides of the US-Mexico Border

Background: Whether immigration patterns and living in the border add to the co-occurrence of alcohol and drug use for the Mexican population and the Mexican-origin individuals in the US is unknown. Methods: We used the US-Mexico Study on Alcohol and Related Conditions that interviewed 2,336 Mexican Americans and 2,460 Mexicans in the border. In Mexico respondents were asked if they ever migrated to the US or have a family member living in the US (328) or not (2,124), while in the US respondents were asked if they were born in Mexico (697), born in the US from Mexican born parents (2nd generation, 702) or born in the US from US born parents (3rd generation, 932). Results: The 12-month prevalence of co-occurring alcohol use disorders and two co-occurring symptoms (hazardous use and quit/control) of drug use disorders among Mexicans with no migrant experience was 0.8%, followed by Mexicans with a migration experience (3.0%), Mexican born respondents living in the US (3.8 %), US 2nd generation (6.6 %) and US 3rd+ generation Mexican Americans (6.3 %). Compared to Mexicans with no migrant experience, the adjusted prevalence ratio was 4.08 for Mexicans with a migration experience, 6.62 for Mexican-born respondents living in the US,  9.86 for US-born 2nd generation, and  11.25 for was US-born 3rd+ generation Mexican Americans. Conclusions: Results help to identify regions and migration patterns at high risk for the co-occurrence of AUD and DUD and begin to unravel causal mechanisms that may underlie this risk.