The findings of this research are consistent with other national studies and indicated that usage of all types of substances among the university students of Jahrom City in Iran is generally lower than in western countries (
21-
23). In this regards, 36.2% of students of Jahrom universities experienced at least one episode of substance usage. This is in line with the findings of Goreishi et al. (
21), among the students of Zanjan universities (40.3%), and also with the study of Jodati et al. (
24), in Tabriz universities (32%).
Findings of this study indicated that the most common substances used by the students were tobacco, alcohol, and opium. A similar study, conducted on the students of Shiraz University of Medical Sciences, Shiraz, Iran, showed that tobacco and alcohol were the most frequently used substances (
20), a finding comparable to the study of Goreishi et al. in Zanjan (
21).
Many studies reveal that the pattern of substance usage among the students of western universities is different from its pattern in Iran, so that alcohol and various opiate are the most common substances used by western college students (
20,
25,
26), while in Iran, hookah and cigarette are at the topmost substances used by the students. Availability of substances and different prohibitive laws could be considered as the determinant factors of this discrepancy (
21). Although there exist several regulations that prohibit usage of tobacco at the university campuses in Iran, however, the law enforcement and monitoring programs are faced with short of efficient implementation (
13).
Many strict prohibitive regulations, enacted against the usage of alcohol and opium, along with the religious beliefs, reduced the rate of consumption of these substances in Iran, compared to several other countries (
20). Nevertheless, increasing usage of alcohol and opium by university students in Iran is of serious concern and deserves appropriate measures to be taken by the decision makers (
24).
Considering different rates of consumption, the risk of substance use among the male students was significantly higher than females. This is in accordance with the findings of a similar study on students of Zanjan universities, which showed the risk and incidence of substance use were significantly higher in males (6.3%) than in females (1.2%) (
21). Another study carried out at Shiraz University of Medical Sciences, Shiraz, Iran, evaluated 532 university students regarding substance use, which was higher among males (4.2%) than females (0.2%) (
27). Numerous studies across the world have revealed differences in drug abuse between males and females, which were consistent with our findings (
28,
29). This is evidenced by the differences in availability of substances to males and females, a condition accounting for increasing access of male students to substance use (
3). Also, multiple factors, such as social stigma, have important effects on the decisions of female students to use substances (
28,
30,
31). The dependence of female students on their families could also be one of the reasons for lower substance use among females than male students (
21).
According to the results of our study, the type of university was another important risk factor for substance use among the university students. By and large, the incidence and risk of substance use among the students of AUJ was significantly higher than in JUMS students, at all levels of substance use frequencies.
The JUMS, as a public university, and AUJ, as a private institution, enroll students from different socioeconomic groups, so that those who attend the private university are generally from wealthier families. It seems that the difference in substance usage between students of these universities relates to affording the cost of substances by the students of the private university (
14), as well as the different lifestyles of students from different socioeconomic groups, which affect their behavior, such as their tendency to substance use (
28).
The results of our study show that the place of residence of students is another important risk factor that impacts substance use. Living alone and living in students’ dormitory were additional risk factors for substance use among the students with the history of at least one episode of substance usage and in those with occasional substance usage. Among the students with sustained substance usage, living alone was a risk factor for such behavior.
The study of Sahraian et al. (
20), in Shiraz, indicated that 22% of the students who lived in the student dormitory, 4% of the students who lived with their families and 57% of the students who lived alone had a history of at least a single episode of substance use, so that the rate of substance use among those who lived with their family was significantly lower than in the other students. Several studies suggest the positive effect of living with family on prevention of substance use among the college students in Iran (
20). Implementation of strict supervision programs, along with attending effective psychological consultation courses by students living in dormitories, could help reduce the prevalence of substance use (
13).
The curiosity and seeking pleasure are the most important impetuses for starting substance use. Students with continuous substance usage mentioned that seeking pleasure and releasing tension were the most important incentives for sustained usage of substance. In the study performed in Zanjan universities, the most important motivators for substance use were pain relief in 32.7%, seeking pleasure in 13.3%, and curiosity in 9.3% (
21). Another study conducted in Shiraz University of Medical Sciences, Shiraz, Iran, revealed that curiosity (59.7%), seeking pleasure (19.2%), and copying friends (9.6%) were the three most common motivators of substance usage (
20), a finding which was consistent with our study.
Lack of sufficient and proper knowledge about the side effects of substance use misleads people to use drugs and substances for pleasure and control of tensions (
3). Appropriate information through educational courses and counseling practices has a positive effect on awareness of people about the realities associated with usage of substances (
32).
Substance usage is considered as a risk factor for students’ health in Iran. Tobacco, alcohol, cannabis and marijuana were the most common substances used by the students of Jahrom universities. Being male and living alone are two important risk factors for substance usage. The curiosity and seeking pleasure were the most important motivators of substance use.
Universities could improve their drug abuse control programs by focusing on the high risk groups, which are identified by relevant studies. It is suggested that several educational and consultation courses could improve knowledge and attitude of students about the detrimental effects and dire consequences of substance usage. It is also suggested that implementing strict surveillance on the behavior of students in dormitories and residential places of students, along with direct cooperation of students’ families, are important in reducing, if not in complete eradication of substance use. Finally, it is worth enacting as number of powerful laws to prohibit substance usage by university students.