Introduction It is widely accepted that psychiatric comorbidity can increase the severity, chronicity, and treatment resistance of psychiatric disorders. In various studies worldwide, it has been estimated that the prevalence of alcohol use disorders in women with disordered eating behaviors (DEB) is situated at between 2.9 and 48.6%. It is worth noting that previous studies have not considered the analysis of the variables that could explain the comorbidity between DEB and alcohol use in adolescents, such as impulsivity, which is the key variable for explaining this comorbidity. On the other hand, most studies have addressed the adult population in psychiatric hospitals or people with eating disorders (ED) or alcohol use disorders. It is considered that those subjects have already developed psychiatric comorbid disorders. Impulsivity could be an unspecific trait that aggravates the psychiatric condition of a determined person and it is therefore more likely for that person to seek specialized care. According to the above, the role of impulsivity in the comorbidity of ED and alcohol use might not be similar to that of the general population, mostly among those who have not yet developed a whole clinical syndrome. Therefore, we consider that it is important to clarify the involvement of impulsivity in the comorbidity between disordered eating behaviors (DEB) and binge drinking (BD) in high school students. It is also crucial to analyze the association between impulsivity and the coexistence of DEB and binge drinking (BD) in female students aged between 15 and 19 years at public high schools in the State of Mexico. Methods Data for this study were drawn from the Project entitled "Prevalence and Factors Associated with Disordered Eating Behaviors in Ado, lescent Women with Different Levels of Urbanization and Migratior Intensity" (CONACyT-SEP-2004-46560). The design for this study is cross-sectional and analytical. A sample of 2357 female students at 11 public high schools in the State of Mexico was randomly selected during the 2006-2007 school year. For data collection for this project, a questionnaire was used that included socio-demographic variables, the Plutchik Impulsivity Scale (PIS), the Brief Questionnaire to Measure Risky Eating Behaviors (BQREB), and the questions on alcohol use included in the Questionnaire of Surveys on Substance Use in Students in Mexico (2003 version). Data were analyzed with the STATA version 10 survey function. Results Impulsivity was associated with the coexistence of DEB and BD (U=224427; p<0.01). The 3.5% of female students with impulsivity presented DEB and BD together vs. 0.6% who did not; 19.6% of female students with impulsivity presented one of the two behaviors vs. 7.8% without this trait. Impulsivity was associated positively and significantly with the coexistence of DEB and BD (t=3.8; p<0.01), regardless of socioeconomic variables, such as the father's educational attainment, the mother's educational attainment, and the number of services in the household. Conclusion The results of this paper indicate a statistically significant association between impulsivity and the coexistence of DEB and BD. This means that there is a greater percentage of coexistence of DEB and BD in female high school students considered to be impulsive in comparison with adolescents without this trait. This occurs regardless of socioeconomic variables, such as the father's educational attainment, the mother's educational attainment, and the number of services in the household. Future research should establish the role of other variables such as depression and examine the association of impulsivity with socioeconomic variables.
