The effect of cross-border mobility on alcohol and drug use among Mexican-American residents living at the U.S.–Mexico border

• Cross-border mobility variables were related to alcohol and drug use and problems.
• "Drug tourism" is a strong predictor of substance use across the age spectrum.
• Substance treatment at the border should be aimed at co-morbid alcohol and drug use.

IntroductionLittle epidemiological evidence exists on alcohol or other substance use and related problems along the U.S.–Mexico border, although the border has been the focus of recent media attention related to the escalating drug/violence “epidemic”. The purpose of this study was to analyze the association of variables related to crossing the border (cross-border mobility) with three substance use outcomes reported for the last year: 1) heavy drinking (5 + drinks per day for men or 4 + for women), 2) alcohol use disorder (AUD), and 3) co-occurring heavy drinking and drug use (any use of illicit and/or non-medically prescribed drugs).MethodsHousehold surveys were conducted, using area probability sampling of 1565 Mexican-American residents, aged 18–65, living at the Texas–Mexico border in the metropolitan areas of Laredo and McAllen/Brownsville.ResultsAmong those 18–29, more frequent crossing of the border was significantly predictive of AUD (OR = 1.61, p < 0.01) and co-occurring heavy drinking and drug use (OR = 1.70, p < 0.01). Staying more than one full day was predictive of AUD (OR = 3.07, p < 0.001) and crossing to obtain over-the-counter or prescription drugs (“drug tourism”) or for nightlife/drinking were predictive of heavy drinking (ORs = 4.14, p < 0.001; 3.92, p < 0.01, respectively), AUD (ORs = 7.56, p < 0.001; 7.68, p < 0.01, respectively) and co-occurring heavy drinking and drug use (ORs = 8.53, p < 0.01; 4.96, p < 0.01, respectively). Among those 30–65, staying more than a full day and crossing for pharmaceutical reasons were predictive of heavy drinking (OR = 2.54, p < 0.001; 2.61, p < 0.05, respectively) and co-occurring heavy drinking and drug use (OR = 3.31, p < 0.001; 4.86, p < 0.01, respectively), while none of the mobility variables were predictive of AUD in this age group.ConclusionsCross-border mobility may play an important role in substance use and problems, especially among those 18–29. Findings also highlight the importance of “drug tourism” in substance use across the age spectrum.