The current prevalence of substance use in this study was 47.9%, 66% in males and 34% in females. As was demonstrated in other studies [13, 18, 25, 34, 37], males had a higher prevalence of substances use than females. Higher use among males may be related to gender roles related to external/social influences and sensation seeking behavior.
The lifetime substance use prevalence in the current study was 65.4%, which was significantly higher than the prevalence found among high school students in Addis Ababa [36] and nearly similar (69.8%) to the finding among college students in Kenya [5]. Low perceived risk of substances by adolescents, community norms favorable to substance use, substances being considered as a “gateways” substance, and the change in community value system might be the possible reasons for the high prevalence.
Similarly the current prevalence of alcohol drinking was found to be 40.9%, which is higher than almost all Ethiopian studies [13, 36] and other African countries [4]. It is more than two fold higher than the result in Dire Dawa (19.6%) [13], significantly higher than the study in Addis Ababa; 26.5% [36], and more than four times higher than the study among secondary students in Nigeria 8.9% [4]. One possible explanation is the easy access and availability of alcoholic beverages in Ethiopia. Drinking alcohol is a socially acceptable as well as a behavior learned from parents and older siblings.
The lifetime prevalence of alcohol drinking in this study was 59% which was nearly two times higher than the life time prevalence in Dire Dawa (34.2%) [13]. It was also significantly higher than a study done among high school students in Addis Ababa (45.7%) [36], and more than seven times higher (9.2%) than in Nigeria among high school students in urban setting [4]. When compared to a study done in similar setting among adolescent students in Cape Town, South Africa (50.6%), the prevalence was higher in the current study [38]. Again, high prevalence may be related to drinking being socially acceptable and readily available during holidays and other festivities in the country as well in the study area. Most often the adolescents start by experimenting with the so called “gateways drugs” such as alcohol.
The current prevalence of khat chewing in this study was found to be 13.8%. This result was higher than a similar study in Dire Dawa (10.9%) [13]. The lifetime prevalence of Khat chewing in this study was 34.9% which is nearly two fold higher than the study in Dire Dawa (18.4%) [13] as well as compared to students in Saudi Arabia (21.5%) [39]. Higher khat use may be related to the fact that khat is widely cultivated and available, and also socially acceptable. Curiosity to test new things might also be a contributing factor for its use. In addition, most adolescents aspire to be popular among their peers; one way to achieve this is through the use of substances.
The current prevalence of cigarette smoking in this study was 6.8% which was slightly higher than the study in Dire Dawa (5.6%) [13] but more than 2 times higher than among adolescents in Addis Ababa (2.9%) [34] and among high school students (3%) [11]. The life time prevalence of smoking in this study was 22.9% which is lower when compared to high school students in Nairobi (32.2%) [23]. Students in our study reported higher lifetime prevalence than the study in Dire Dawa, Ethiopia (13%) [13], and more than 2 times higher than the study in Addis Ababa 10.1% [11]. Again, this study was slightly higher than the 16.9% rate reported among teenage students in a city of South Brazil [40]. Easy access and availability, and curiosity to try new things may be reasons for the higher rates in our study. The absence of legal provision to control the spread cigarette aggravates the use in the area.
Substance use was associated significantly with gender of the students. The current study was similar to results in Addis Ababa [34]. These indicate that males are at greater risk of substance use, perhaps due to social norms and gender roles.
Students whose mothers’ had technical/vocational certificate and some university/college diploma have a lower risk of substance use, respectively, consistent with findings among African American students on tobacco use [41].
Siblings’ use of substances emerged as the stronger predictor of substance use, with a nearly 3 fold increase among students who reported having siblings’ who used substances. Findings from other studies on adolescent substance use in South Africa have also documented an association between substance use by other members of the household and adolescent substance use [38], indicated use may be a learned behavior.
The current study revealed that there is association between low perceived risks of substance use and substance use. Students with low perceived risks of substance use were 1.73 times more likely to use substances compared to their counter parts with high perceived risk of substance use. Studies in Maine and Oregon in the U.S. also found similar results. Low perceived risk of substance use is more strongly associated with the use of alcohol and cigarettes [42]. Adolescents who don’t know the dangers of substance use may be more likely to use them.
Family history of alcohol and substance use was risk factors for substance use. Studies with high school students in Ethiopia also revealed an association between family history of alcohol and substance use and substance use [34].
The study in Dire Dawa showed fathers/guardians use of alcohol and mother/female guardians’ use of alcohol were significantly associated with substance use [13].
A study in South Africa among high school adolescents also documented similar evidence; substance use by other members of the household is significantly associated with substance use [38]. Similarly, in Zambia, parental smoking had positive association with adolescents’ substance use [22]. The finding is also consistent with the cross-national comparisons of risk and protective factors for adolescents; substance use in United States, Australia, Brazil and the U.S. [40, 42–44].
These all studies give additional evidence that family history of alcohol and substance use leads to a learned behavior among children regarding substance use.
Friends’ use of substances was also found to be predictor of substance use, with students who had friends that used substances had 2.14 times higher risk of using substances than those students who had no friends that used substances. Similar results were reported for smoking in Addis Ababa [37]. This finding is further evidence of the impact of social norms and learned behaviors on adolescents’ use of substances. Peer pressure is very powerful factor for influencing behavior especially in young people. Adolescents who affiliate with substance use peers may be pressured to use substances.
Students in our study with poor academic performance were at higher risk of using substances when compared with students with good academic performance, consistent with findings among adolescents in the U.S. and Australia for cigarette and alcohol use [42, 44], among Ethiopian high school students [36].
Community norms favorable to substance use was found to be a predictor for substance use, with nearly 2 times the odds of using substances in areas with community norms favorable to substance use, similar to findings in Australia [42, 44]. Reasons could be related to exposure to such behaviors in various media (films and TV), commercial values of substances, and permissive law of the country on substance use.
On the other hand, protective factors such as religiosity and social skills were associated with lower substance use. Being religious decreased the risk of substance use by 54%, consistent with past studies [27, 28, 44]. Religious teachings discourage the use of substances and may, thus, protect people from engaging in self destructive behaviors including substance use.
Having social skills reduced the risk of substance use by 39%, consistent with findings in the past studies for alcohol and drug use (43, 46). Adolescents with effective communication skills may better withstand peer pressure to use substances.
Although some research suggests that community opportunity for prosocial involvement is a protective factor for adolescent substance use [42], the current study did not show a significant association. One possible justification for the discrepancy might be differences in measurement and the difference in the socio-demographic status of the samples across studies.
In addition, poor family management was a strong predictor of adolescent substance use in other research [42, 44] but in our study. However, this finding should not be taken to suggest that poor family management is not related to substance use in adolescents. Instead, research must be done to clarify the association of family and community factors among adolescents using larger samples and across wider geographical areas, and in longitudinal/cohort studies.
Limitations & strengths of the study
Social desirability bias may have affected participants’ response. Prevalence rates were also self-reported and dependent on the accuracy with which the participants recalled and reported such use. Additionally, the cross-sectional design only allows for description of behavior at one point in time. A major strength of our study is that results are largely consistent with past literature, and increasing generalizability of our findings.