Introduction
The trend of alcohol consumption in Thai adolescents has increased considerably in the last decade. According to the Centre for Alcohol Studies of Thailand, the prevalence of alcohol consumption among high school students increased from 19% in 2007 to 26% in 2017 [
1]. Early alcohol intake, particularly before the age of 15, can predispose adolescents to alcohol-related problems, as well as poor adult outcomes [
2‐
4]. However, when other individual and environmental variables are well controlled, the impact of early alcohol exposure; initiation of an adolescent’s own drinking, on adult outcomes could be reduced [
3]. Previous research in Thailand found that the average age of first exposure to alcohol among grade 10 students in Nan province, Northern Thailand, was 14.5 years, with the lowest age of 9 years [
5]. In addition, among the sample of female students in high schools in the Eastern province of Thailand, more than one third of female drinkers had their first alcohol consumption before high school, and 15.6% had first been exposed when they were younger than 10 years old [
6].
In Thailand, it is against the law for retailers to sell alcoholic beverages without required licenses [
7], and anyone –including parents, relatives, and caregivers –is prohibited from giving an alcoholic beverage to a child or adolescent under the age of 20 [
8] and 18 years old [
9]. Many Thai parents, on the other hand, become the suppliers to their children with the belief of protecting them from alcohol–related harms and alcohol use disorders when their reach adulthood, especially in the case of daughters. In addition to previous literature in Australia and Canada reporting that parents were a major source of alcohol supply to adolescents [
10,
11] and were found to be a protective factor for adolescent alcohol consumption [
10,
12]. On the contrary, recent research found that adolescents who had their parents provide them with alcohol had a higher risk of binge drinking, alcohol–related harm, alcohol use disorder, and other alcohol outcomes than those who did not have their parents provide them with alcohol [
13‐
17].
Not only the parental supply of alcohol, but also other supplies of alcohol play the important role in the outcome of alcohol outcome. Previous studies found a higher degree of impact of peer supply on adolescent alcohol use and outcomes [
12,
14,
18]. However, increasing sources of alcohol supply in adolescents did not guarantee a higher probability of alcohol outcomes. Mattick et al. (2018) found that the odd ratios of two sources of alcohol supply; parents and others, in binge drinking and alcohol abuse were less than one source of alcohol supply, especially from non-parental sources, while the odd ratios of two sources of alcohol supply on alcohol-related harms, alcohol dependence and alcohol use disorder were definitely higher than one source of alcohol supply [
14].
Other factors influence the effects of adolescent alcohol use in addition to the sources of alcohol supply. Previous studies have found that drinking alcohol is influenced by social and physical variables. Regarding social issues, the student’s values or behavior, societal standards, school-related variables, and liquor advertising can all have an impact on a minor’s behavior and alcohol use [
19]. In terms of a physical variable, earlier research discovered that the alcohol flush reaction, an aversive reaction when drinking alcohol including erythema of the face, nausea, and palpitation caused by the deficiency of enzyme aldehyde dehydrogenase (ALDH), increased the rate of occurrence of harm to health in alcohol drinkers although decreased harmful alcohol use, such as dependence, abuse, maximum drink, or binge drinking over the course of a lifetime [
20‐
22].
The objective of the study was to investigate whether different sources of alcohol supply were associated with different experiences of alcohol-related harm and differing severity of alcohol use disorder in Thai 7th grade middle school students. For the purpose of controlling confounding effects, there are additional socioeconomic, behavioral, and physical variables in the model. These variables included household income, media exposure to alcohol advertising, biological responses to alcohol, and academic performance.
Discussion
This cross–sectional study aimed to investigate the relationship between sources of alcohol and related factors, alcohol–related harms, and alcohol use disorders among 1187 Thai adolescents using the baseline characteristics of a middle school cohort in Thailand conducted in 2018. We found that among Thai teenagers, the prevalence of any alcohol–related harms and alcohol use disorders in the past 12 months was 22.2 and 22.0%, respectively. The major source of alcohol supply in this study was parents. This was consistent with the previous studies [
24,
25]. After controlling for the effects of confounders, Thai seventh grade students who had ever sip or drank alcohol in the previous 12 months exhibited a significant influence of peer/sibling single supply of alcohol on both outcomes: any alcohol–related harms and alcohol use disorder. Although there was no statistically significant association between a single source of parental alcohol supply and both outcomes, increasing sources of alcohol provision escalated the probability of adolescents experiencing alcohol–related harms and the severity of their alcohol use disorder.
A single parental source of alcohol supply was found to be unrelated to any alcohol–related harms or the severity of alcohol use disorder. However, the result found that the parental or relative supply of alcohol with peers/siblings was significantly related to both outcomes in this study. The former was in line with some previous studies that found no causal association between parental alcohol supply and adolescent alcohol problems [
26]. The insignificant relationship between parental supply of alcohol and alcohol outcomes in this study was explained for many plausible reasons. First, it was possibly because parents monitored, supervised, and limited alcohol consumption in adolescents [
26]. Second, this was in part related to the analysis of the cross-sectional data. The previous literature found the significant adverse effect of parental, ever-sips or whole servers, on adolescent alcohol outcomes, including binge drinking, any alcohol-related harms, and symptoms of alcohol use disorder in the second to fifth waves of cohort observation, if compared with no supply in the first wave [
14,
15,
27,
28]. This suggests that the single parental alcohol provision was neither a protective nor a risk factor for alcohol use issues in Thai adolescents. The East-West attitudes and norms would also be concerned about different results of the associations between parental supply of alcohol and alcohol outcomes. However, no empirical study was found in Asian countries.
However, alcohol supply was strongly linked to any alcohol–related harms and the severity of alcohol use disorder in Thai seventh-grade middle school students who had drank alcohol beverage in the previous 12 months. Peer influence had a major effect on adolescent drinking, according to previous research, due to friend selection, peer network dynamics, and unsupervised time with peers [
19,
29,
30]. Adolescents who acquired alcohol from sources other than their parents were more likely to report alcohol–related problem behaviors, according to a previous worldwide study [
18]. It is possible that unhealthy social networks, such as those surrounded by people who consume alcohol, could be a risk factor for adolescent alcohol use.
However, obtaining an alcohol beverage from two or more sources (eg, both parents and peers/siblings, or both relatives and peers/siblings) not only increased the odds of experiencing alcohol–related harm and the severity of alcohol use disorder, but also increased the odds with higher magnitude than obtaining alcohol from a single peer/siblings source. The result was consistent with previous evidence that found the greater odds ratio of alcohol outcomes when the adolescent obtained alcohol from the parents in addition to other sources [
14,
18,
28,
31]. Parents could not limit alcohol consumption among their adolescents. This caused risky drinking or alcohol misuse among adolescents without supervision [
28,
32]. The result confirmed the previous discussion that unhealthy social networks increased the greater risk caused by alcohol use among adolescents. Furthermore, if parents relinquish control of their children for a specific cause, such as the fact that the adolescent’s school is located far away from their house. This forces children and adolescents to live with relatives or in dormitories alone. If strict parental supervision is reduced, children and adolescents will have more opportunities to drink alcohol without parental supervision.
Insufficient family income was found to be significantly correlated with alcohol-related harms and the severity of alcohol use disorder. This was consistent with the results of previous studies, which found the significant association between low family income and adolescent alcohol use, alcohol drinking pattern, and alcohol problems [
33‐
36]. On the other hand, some prior studies reported contradictory results on the effect of socioeconomic class on alcohol consumption. A high socioeconomic level was found to be substantially associated with increased teenage alcohol use through increased parental alcohol drinking and a change in high society perceptions of alcohol as a means of relaxation and stress release [
37,
38]. The study also found significant relationships between middle schoolers’ poor academic performance and their both alcohol outcomes. The finding was consistent with prior research that identified low academic performance as a strong predictor of substance use, including smoking, alcohol, and drugs, among high school students [
39,
40]. When studying at the undergraduate level, it was discovered that poor academic performance was not significantly associated with adolescent drinking habits [
41]. This emphasized societal expectations that favored families with high socioeconomic standing and children who excelled at school. Adolescents with poor academic performance, especially those who were labeled “bad students” when they had low academic performance, tend to lose interest in the lessons that they are not good at and move their focus to other topics.
Other risk factors found in both associations included binge drinking and alcohol flushing reaction. The latter is in contrast with previous studies reporting flushing reaction as a protective factor against alcohol dependence or the maximum lifetime number of drinks within 24 hours [
20,
39,
42]. Since this study is a cross–sectional study at a very early age of alcohol use, the protective effect of the flushing reaction may not be revealed until later in life. Furthermore, the flushing reaction after drinking alcohol might be viewed by teenage drinkers as an effect of alcohol that led them continue drinking. In contrast, students who did not have the reaction might stop or stop drinking, since they did not feel the alcohol effect regardless of whether the effect is aversive or rewarding.
However, sex, exposure to alcohol advertisements on social media, and location were not significantly related to alcohol-related harms or the severity of alcohol use disorder. Different from previous research that found the significant association between female and alcohol outcomes [
12]. This is in part due to the fact that the respondents were between 13 and 15 years. Although exposure to alcohol advertisements did not associate with adolescents with alcohol use disorder or alcohol–related harms in this study, exposure could affect the initiation of alcohol as previously shown [
43]. An additional analysis to include students who did not drink alcohol could show different results with respect to alcohol advertisement.
There were some limitations in this research. First, this was a cross–sectional study, it was insufficient to definitively determine the causal relationship between alcohol provisions and alcohol-related problems among Thai youth. Additionally, due to the lag time of juvenile alcohol problems, this cross-sectional study may underestimate the magnitude of the impact of parental and other alcohol provisioning on Thai adolescents’ alcohol problems. Second, this study excluded other behavioral risks, including drug use and smoking, and excluded the variability of number or frequency of alcohol supply from each source that could interact with alcohol consumption. This would be a space for future research. Third, recall bias could arise in the study, particularly when adolescents were asked about their alcohol consumption and problems in the previous 12 months. Finally, the limitations of the study include that the returns of the surveys from the parents and students were not separated. Bias of the data might occur when both know the answer. However, students are the persons who returned the survey back so the parents may not know the answers of the students but not vice versa (students may know the answer from the parents). Such that students would answer the survey more freely without being afraid that the parents may know their answers.
Our results did not support parental guidance in teaching or giving children a drink or sip of alcohol within family to prevent related harms when drinking outside with their peers. A longitudinal study to follow the students further would reveal more the effect of parental supply of alcohol and other related factors on alcohol–related harms and alcohol use disorder.
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