In the field of smoking, adolescence is an important period that poses a great challenge in the field of control and prevention of smoking (1). Most international studies show that about 85% to 90% of smokers start smoking before the age of 20. Smoking in adolescence also predicts its use in adulthood (2, 3). Smoking just a few cigarettes in adolescence increases the risk of smoking 16 times in adulthood (2).
In addition to cigarette smoking as the most common type of tobacco use (4), using hookah in many parts of the world has become the first or second most common method of smoking among adolescents (5). Exposure to nicotine by using a hookah is addictive (6), and evidence suggests that young people who like hookah smoking are more likely to start smoking (7). This illustrates that risk factors for cigarette and hookah use in young people may be common (8).
Cigarette and hookah smoking in adolescents not only increases the risk of many diseases in the short term such as respiratory disease, asthma, and decreased lung function, but also increases the risk of serious chronic diseases such as lung cancer, heart disease, and stroke (9,10). If the current trend of smoking continues, 250 million children and adolescents who continue to smoke until adulthood will die from health problems related to smoking (11).
About 80 percent of the 1.1 billion smokers worldwide live in low- and middle-income countries, where the burden of tobacco-related illness and death is high (12). Smoking has increased in most developing countries over the past 20 years. The World Health Organization has described smoking as an epidemic in developing countries (13,14). Between 1990 and 2009, smoking in Western Europe fell by almost 26 percent, while smoking increased by about 60 percent in Africa and the Middle East (15). Although most tobacco control efforts focus on preventing smoking, 80,000 to 100,000 adolescents worldwide start smoking every day, and almost half of them become regular smokers (16). Epidemiological data from countries that have monitored hookah use have drawn alarming trends. In the Middle East, hookah has quickly replaced cigarettes as the most popular method of tobacco use among young people, and in several other parts of the world, it has become second only after cigarette smoking (17).
About 31% of men and 11% of women worldwide smoke regularly (18). The prevalence of smoking among adolescents in European countries is very high, from 2% (Finland and Norway) to 25.7% (Ukraine) among boys and 3% (Finland and Norway) to 26.3% (Italy) for girls, respectively. (19). In the Eastern Mediterranean (EMR), the percentage of adolescent smokers is increasing. Findings from the Global Youth Survey show that 2% of girls and 7% of boys in EMR are smokers (20). Particularly in the Middle East, several epidemiological surveys have demonstrated the dramatic popularity of hookah among young people (21,22). In a large study of 100,000 students at 152 universities in the United States, the prevalence of regular hookah use was 8.4 percent (23). A multi-country study including a sample of school children aged 13-15 in several countries of the Arabian Peninsula (Bahrain, Oman, Qatar, Saudi Arabia, UAE, Kuwait, and Yemen) showed that the prevalence of hookah was from 9% to 15% and was more than the prevalence of cigarette smoking (24).
Iran has one of the youngest population indices in the world among developing countries (25). Despite many efforts to reduce or prevent smoking among Iranian youth, this habit is still common and has even been shown to be growing (26). A list of countries with a traditional prevalence of tobacco use among people aged 15 and over was published by the World Health Organization in 2016, with Iran ranking 84th with an 11.1% prevalence (27). A cross-sectional study conducted in Tehran during 2014-2015 with a sample number of 1830 citizens over 15 years of age, the prevalence of hookah smoking was 17.6%. The prevalence of hookah use in men was significantly higher than in women (24.2% vs. 11.3%) (28). In another study, 1524 students aged 14-18 (764 boys and 760 girls) were selected. The prevalence of smoking was 9.5% and hookah was 10.4%. About 3.7 percent of teens used both cigarettes and hookahs, and 16 percent used at least one of them. In boys compared to girls, the prevalence of smoking (13.1% vs. 6.4%) and hookah (13.7% vs. 7.1%) was higher (29).
Adolescence is an important stage for the onset of high-risk behaviors due to adolescents' lack of understanding of the risky consequences of their behaviors (30). Smoking is a complex behavior that is associated with psychosocial, economic-political, and biochemical factors and cannot be a single reason to start smoking in adolescents (31). Many researchers have considered smoking behavior in adolescents as a development in a series of stages. Due to the participation of various disciplines such as psychology, epidemiology, behavioral sciences, etc. in research on smoking, there are various definitions of the stages of smoking. Although starting and continuing to smoke is inherently a continuous process, hundreds of studies have attempted to break this process down into steps that include primary and secondary prevention. A study in 1980 suggested that smoking has a complex course and takes several steps for a person to become a smoker (32). Smoking behavior among adolescents can include several stages of development: pre-contemplation, contemplation, trial or initiation, experimentation, regular smoking, and addiction to nicotine or daily smoking (33).
Relatively stable personality traits are specific characteristics and main indicators of behavior (34). Many studies have shown that personality is one of the main risk factors associated with abusive behaviors (35), so it is vital to examine the extent to which personality affects negative health behaviors (36). Researchers have suggested that individual, familial, and social risk factors may lead to nicotine dependence. Among these factors, personality traits that make a person sensitive to nicotine can play an important role in this process. Thus, psychological factors can play a decisive role in determining who starts smoking, who continues, and who quits smoking (37).
One of the main personality traits is extroversion and introversion. Extroversion and introversion are the main dimensions of human personality. These terms were widely popularized by Carl Young (1920) (38). Extroversion is manifested in the tendency to go out, talkativeness, and energetic behavior, while introversion is more pronounced in individual behavior and restraint (39). The study of personality traits and smoking has been started in the 1970s, and almost from the very beginning, extroversion has been considered as one of the main factors (40). Most studies that have examined extroversion through smoking have either examined this association in adults (41,42), or only in developed countries (34,42,43), or the form of other aspects of personality traits (34,36,41,43). Also, the results obtained from previous studies are contradictory, so that some of these studies have found a relationship between these factors (36,44,45) and others have not (46,47). Also, no study has been found to measure the effect of extroversion by going through the stages of smoking and hookah. Therefore, considering that it has been proven that this relationship needs to be studied in different societies, including developing societies such as Iran (41) and also the need to study this relationship as a longitudinal study with an approach to smoking and hookah use in adolescents, (To increase the accuracy of primary and secondary prevention), the present study was conducted to assess the effect of personality type (extroversion/introversion) in transition between smoking stages and use the results in smoking prevention programs.