IntroductionSubstance abuse and dependence has become a social problem that afflicts millions of individuals and disrupts the lives of their families and friends. A single example reveals the scale of the problem: in the United States, each year, more women and men die from smoking-related lung cancer than from colon, breast, and prostate cancers combined (Kola & Kruszynski , 2010). In addition to the personal consequences of so much illness and premature death, there are disastrous social costs: enormous expenditure on medical and social services; millions of hours lost in the workplace; high rates of crime associated with illicit drugs; and dozens of children are harmed by their parents' drug-addicted behavior (Lee, 2010). This article will examine the different theories used to understand drug abuse and addiction and how they can be prevented and treated. Theories (Models) for Understanding Substance Abuse and Dependence: Old and New Any comprehensive theory (model) of substance abuse must answer several difficult questions: What environmental and social factors in an individual's life? lead to start abusing a drug? What are the factors that push them to continue? What physiological mechanisms make a drug rewarding? What is addiction, behaviorally and physiologically, and why is it so difficult to quit? These questions can be answered within the major theories (models) described below using an integrative approach that addresses the problem of substance abuse and dependence as an urgent but elusive goal (Kauffman & Poulin, 1996). The Moral Model: The First Approach Explaining drug addiction simply meant blaming the addict for their lack of moral character or lack of self-control. Explanations of this kind often had...... in the middle of the document......alcohol policy, a look back and a future.Journal of Psychoactive Drugs, 42(2), 99 -114. doi:10.1080/02791072.2010. Padgett, D. L. (2010). Examining “Ethical Challenges to Intervening in Drug Use: Issues for Policy, Research, and Treatment.” Journal of Social Work Practice in Addiction,10(1), 99-123. doi:10.1080/15332560903408821. Robins, L.N. & Sloboyan, S. (2003). Post-Vietnam heroin use and injection among returning US veterans: clues to prevent injection today. Addiction, 98, 1053-1060. Scott, CK, Dennis, ML and Laudet, A. (2011). Surviving drug addiction: The effect of treatment and abstinence on morality. American Journal of Public Health, 101(4), 737-744. Tian, ​​M., Mao, R., Wang, L., Zhou, Q., Cao, J., & Xu, L. (2011). Interaction between behavioral despair and addictive behaviors in rats. Physiology and behavior, 102(1), 7-12.