The Health Belief Model postulates that health and risk-taking decisions are based partially on individual perceptions of personal susceptibility to an adverse condition. Decisions also are based on beliefs regarding seriousness of the condition. The initial decision to accept the risk involved with tobacco use makes it easier to progress to the risk associated with illicit drug use. Psychologists refer to the progression of drug-taking involvement as a “developmental sequence.” The initial decision to use tobacco makes the risk involved with using other drugs seem less severe. For example. injecting heroin might be perceived as a near suicidal risk for a nonsmoker. However, for people who smoked cigarettes for years. despite knowledge of their harmful effects, using heroin may seem only slightly more dangerous than behaviours they currently engage in and have thus far survived. Therefore, tobacco may act as a risk perception stepping stone which reduces perceived severity of the dangers involved with illegal drug use.

Similarly, tobacco may undermine the “perception of personal susceptibility” portion of the Health Belief Model. Youthful users of tobacco who fail to see any immediate lethal consequences from their use likely conclude the purported dangers of tobacco as greatly exaggerated. They may conclude that the health warnings against illicit drug use are exaggerated or that they are somehow not susceptible to the adverse effects of drug use. This belief enhances the likelihood of using illegal drugs.

Issues of risk perception apply to legal risks as well as health risks. Adolescent purchase, possession, and use of tobacco is illegal in every state. In Social Learning Theory terminology, as teen-agers break tobacco-related laws they develop “self-efficacy perceptions” in their ability to break substance abuse laws. The Health Belief Model suggests these adolescents simultaneously are creating the belief that breaking substance abuse laws is not serious and their likelihood of punishment is low. These perceptions about tobacco laws may erode the deterrent effect of laws prohibiting use of illicit drugs.

One way to reconcile beliefs regarding severity and personal susceptibility of drug use involves rationalizing the behaviour. Decisions that violate personal beliefs regarding what is wise. right, and appropriate can create “cognitive dissonance”. Rationalization provides a psychological defense mechanism to justify the behaviour. Comments such as “We all got to go sometime.” “I could get killed in a car wreck tomorrow.” or “Grandpa smoked and lived to be 80” are examples of rationalizations, individuals who use these rationalizations to justify cigarette use might easily transfer these psychological defense mechanisms to legitimize use of illicit drugs.

Studies indicate nearly 90% of regular smokers get addicted to nicotine. Researchers show surprise at how rapidly nicotine addiction is acquired among teen smokers. Cigarettes represent teenagers’ first personal experience with the phenomenon of true drug addiction, and most teen smokers freely acknowledge being “hooked.” Adolescent nicotine addicts observe that life goes on despite their dependence on cigarettes. This situation causes adolescents to develop a lower risk perception of drug addiction in general. Addiction to a drug comes to be considered neither abnormal nor risky. Spending significant amounts of discretionary income for drugs also acquires a sense of normalcy.