Individual and Environmental Factors Associated with Tobacco Smoking, Alcohol Abuse and Illegal Drug Consumption in University Students: A Mediating Analysis.

Substance abuse is a major and prevalent public health concern among university students. Tobacco smoking, risky alcohol behavior, and illegal drug consumption may lead to health problems and behavioral and academic issues. Several individual and environmental factors associate with substance abuse in this population, and the mediating effect of alcohol abuse in the relationship between tobacco smoking and drug consumption is yet to be explored. The purposes of this study were to evaluate the association of individual and environmental factors and substance use, and to analyze the relationship between tobacco smoking, alcohol abuse, and drug consumption, considering alcohol abuse as a possible mediator. A total of 550 Spanish undergraduate and postgraduate students completed several questionnaires regarding their smoking status, alcohol use, and drug consumption during the last six months. Bivariate and multivariate analyses were conducted to explore associations between factors. Direct, indirect and mediating effects were tested using a partial least squares approach (PLS-SEM). The results indicated that substance abuse is associated with being male, living with other students, and combined substance consumption. PLS-SEM showed a significant effect of tobacco smoking and alcohol abuse on drug consumption. Alcohol abuse plays a mediating role in the relationship between tobacco smoking and drug use.