The relationship between social inequalities, substance use and violence in border and non-border cities of northern Mexico

We know little about determinants of violence and drug use in Mexican northern cities, places considered to be at high risk for alcohol, drug use, and violence, including crimes and homicides. Methods: Data are from the US-Mexico Study on Alcohol and Related Conditions (2011-2013), a survey of respondents living in the border metropolitan areas of Nuevo Laredo (n = 828) and Reynosa and Matamoros (n = 821) and in the non-border metropolitan area of Monterrey (n = 811). Associations between violence (interpersonal, direct community [such as physical attack] and indirect community violence [such as heard gunshots]), drug related activities and neighborhood insecurity with alcohol use disorders (AUD), drug misuse (illicit and out of prescription) and area-level disadvantage (ALD) were estimated with multilevel logistic models, controlling for covariates. Results: Substance use was generally related to violence regardless of ALD in these northern cities in Mexico (statistically significant odds ratios range: 0.68-4.24). AUD was associated with 3 forms of violence and also with drug-related activities, but not with neighborhood insecurity. Both illicit drug use and misuse prescription medicines seem to act in unison and were related only to indirect community violence and drug related activities. ALD in these cities was associated with physical violence and neighborhood insecurity. An inverse relationship between illicit drug use and neighborhood insecurity was an unexpected finding. Conclusions: AUD and drug use were associated with violence and drug involvement regardless of ALD. Neighborhood insecurity depended mainly on ALD and to an inverse relationship with illicit drug use that needs further study.