Drug use opportunities and the transition to drug use among adolescents from the Mexico City Metropolitan Area

Abstract

The earliest stage of drug involvement is being presented with the opportunity to use drugs. During adolescence these opportunities increase. Because of the scarcity of data for the Mexican population, the aim is to estimate the prevalence of drug use opportunities among Mexican adolescents, the prevalence of drug use among those who were presented with the opportunity, and the socio-demographic correlates of both. A multistage probability survey was carried out among 12–17 year olds from Mexico City. Adolescents were administered the adolescent version of the World Mental Health Composite International Diagnostic Interview. The response rate was 71% (n = 3005). Descriptive and logistic regression analyses were performed considering the multistage and weighted sample design. Twenty-nine percent has had the opportunity to try illicit drugs; of those presented with an opportunity, 18% has done so. Males, older adolescents, school drop-outs, and those whose parent has had drug problems are more likely to have been exposed to drug use opportunities while more religious adolescents are less likely. Given the chance to try drugs, older adolescents and school drop-outs are more likely to do so and those with high parental monitoring and religiosity are less likely. These results suggest that less substance use among females in Mexico may be due in part to fewer opportunities to use since females were equally likely to use drugs given the opportunity. Given the increase in opportunity among older adolescents, preventive efforts should start by age 12 and with special attention to adolescents who have dropped out of school.

Introduction

Being presented with an opportunity to use drugs is the first step of drug involvement such that drug use is only possible given exposure to drug use opportunities. Understanding the phenomena of drug use opportunities has been deemed important for understanding the mechanisms of transition from one stage of drug involvement to another (Wagner and Anthony, 2002) and has clear implications for preventive strategies aimed at reducing drug use by reducing drug use opportunities. Furthermore, many factors found to be related to drug use (gender, parental monitoring, etc.) may actually only be related to drug use insofar as they relate to exposure to drug opportunities rather than the decision to use once an opportunity has been presented (Chen et al., 2005, Delva et al., 1999; Van Etten and Anthony, 1999). Reliable data on drug use opportunities in different cultural contexts may account for some of the large variation in drug use prevalence in different countries.

During adolescence the opportunities for drug use increase dramatically as compared to childhood. The lifetime prevalence of illicit drug use among adolescents aged 12–17 in Mexico City is 5.1% for males and 3.0% for females, the drug of choice being cannabis. This is similar to the national estimate of 4.9% for males but greater than the national estimate of 1.6% for females. In the Northern states which border the U.S. and lie on major drug trafficking routes, drug use has risen above the national average (Bucardo et al., 2005). However these estimates are still less than in other non-Latin American countries (Medina-Mora et al., 2003). One possible explanation for this difference is fewer opportunities for use. The only other study on drug opportunities exposure in the Mexican population that we are aware of found one in four students from two Mexico City middle schools to have been exposed to drug opportunities (Wagner et al., 2003). Since only 59% of Mexican youth between 16 and 18 attend school (Secretaría de Educación Pública, 2006), and adolescents in school have less risk of drug use, this data has clear limitations. A study of secondary school students in seven Latin American countries, not including Mexico, estimates that 11% of students have had drug use opportunities (Dormitzer et al., 2004). This compares with 78% of US young adults having an opportunity to try cannabis by age 21 (Chen et al., 2005).

Because of the importance of drug opportunities exposure to the early stages of drug involvement and the paucity of information for the Mexican population, the objective of this article is to estimate (1) the lifetime prevalence and age of first opportunity to use any type of illicit drug among a representative household sample of adolescents aged 12–17 in the Mexico City Metropolitan Area, (2) the prevalence of drug use given the opportunity to use, (3) the time latency between first opportunity and first use, (4) the socio-demographic correlates of having an opportunity to use drugs and (5) the socio-demographic correlates of drug use given the opportunity. The socio-demographic correlates studied include sex, age, student status, parental monitoring, parental educational attainment, parental drug problems and religiosity. These factors are all well-known determinants of substance use (Anthony and Helzer, 2002).