In 2003, the prevalence of TS misuse was 5.0% (95% CI 3.8% to 6.5%) among boys and 12.6% (95% CI 10.7% to 14.7%) among girls, resulting in an overall rate of 8.8%. By 2019, the rates significantly (p<0.001) increased to 11.3% (95% CI 9.6% to 13.3%) among boys and 17.5% (95% CI 15.4% to 19.7%) among girls, with an overall prevalence of 14.6%. The lifetime prevalence of TS misuse among girls demonstrated a decline from 2003 to 2007, followed by a consistent increase until 2019. In contrast, the lifetime prevalence of TS misuse among boys remained relatively stable until a notable increase from 2015 to 2019 (figure 1).

Prevalence (% with 95% CI) of tranquilliser and sedative (TS) misuse and statistical significance of prevalence change (p value) among boys and girls aged 15‒16 years old in Estonia, ESPAD (European School Survey Project on Alcohol and Other Drugs) survey 2003‒2019.

Among boys who reported medical use of TS, the prevalence of TS misuse exhibited a significant increase from 21.1% (95% CI 13.9% to 30.0%) in 2003 to 41.4% (95% CI 32.3% to 50.9%) in 2019 (p=0.006). However, there was no statistically significant change in the prevalence of TS misuse among girls who reported medical use of TS during the study period, with the rate remaining at 44.1% (95% CI 36.0% to 52.4%) in 2019 (p=0.951) (figure 2).

Prevalence (% with 95% CI) of tranquilliser and sedative (TS) misuse and statistical significance of prevalence change (p value) among boys and girls aged 15‒16 years old in Estonia who reported medical use of TS, ESPAD (European School Survey Project on Alcohol and Other Drugs) survey 2003‒2019.

The adjusted logistic regression model revealed that perceived easiness of obtaining TS significantly increased the odds of TS misuse compared with those who perceived access to TS as impossible. Additionally, the odds of TS misuse were significantly increased among adolescents who reported medical use of TS, having friends who had misused TS and smoking cigarettes daily within the past 30 days. These factors were identified as common risk factors for TS misuse among both boys and girls. Sports activity did not show consistent associations with TS misuse across genders. Only for boys, one to two occasions of cannabis use within the past 30 days increased the odds of TS misuse. For girls, not being satisfied with their relationships with friends was identified as a risk factor for TS misuse. Neither family SES, parental control, satisfaction with the relationship with mother and father, skipping school nor alcohol use showed significant association with TS misuse (table 1).

Logistic regression models results for association between TS misuse (yes vs no) and explanatory factors among adolescents in Estonia 2003–2019

This study focused on adolescents’ lifetime TS misuse and how various explanatory factors (perceived easiness of getting TS, medical use of TS, family-related, friends-related and school-related factors, probable risk behaviours and leisure time sports activity) were related to the TS misuse among adolescents in Estonia in 2003–2019.

The prevalence of TS lifetime misuse among adolescents in Estonia exhibited a significant increase from 8.8% in 2003 to 14.6% in 2019. However, while the lifetime prevalence of TS misuse among girls declined from 2003 to 2007 before steadily increasing until 2019, the prevalence among boys remained relatively stable until a significant increase from 2015 to 2019. The study based on the ESPAD 2003 data found that the prevalence of TS misuse among European adolescents was 5.6% (6.6% in 20196), the prevalence in Estonia was estimated at 9.1% in 2003, and the higher prevalence of TS misuse was only in Lithuania (13.6%), France (12.6%), the Czech Republic (11.0%), Hungary (10.2%) and Belgium (9.3%).3 The prevalence of TS misuse among adolescents varies considerably across studies and countries. A 2014 study conducted in five EU countries revealed that the average lifetime prevalence of sedative misuse among students aged 12–17 years old was at only 1.6%.5 Additionally, among students from the high school graduating class of 2007–2011 in the USA, the estimated lifetime prevalence of benzodiazepine misuse was 7.5%.28 In the current study, TS misuse among boys increased by 2.3 times (from 5.0% to 11.3%) and by 1.4 times among girls (from 12.6% to 17.5%). Notably, girls were nearly twice as likely to misuse TS compared with boys, emphasising the need for gender-specific interventions and targeted prevention strategies. According to a study based on the ESPAD 2003 data, in 13 EU countries, girls were significantly more likely to misuse TS compared with boys, except in Finland where boys demonstrated a higher prevalence of TS misuse, while no gender differences were observed in 17 countries.3

The increasing prevalence of TS misuse in Estonia may potentially be associated with shifts in social norms and attitudes, as suggested by the declining popularity of smoking and alcohol use among young people.45 It is a speculation that these changing attitudes towards traditional substances may lead to the adoption of alternative risky behaviours such as TS misuse. However, this conjecture requires further empirical research.

The observed increase in TS misuse prevalence may also be attributed to the perceived easy availability of these drugs. From 2003 to 2019, the proportion of Estonian schoolchildren perceiving TS as easily accessible without a prescription increased by 1.3-fold. In 2019, 21.0% of boys and 27.1% of girls considered TS to be easily accessible. Similar trend was observed in a study among Spanish schoolchildren with a 1.7-fold increase in the proportion of students who considered TS to be easily accessible.1 Additionally, analysis of the ESPAD 2003 data showed, on average, 20.7% (ranging from 9% to 42%) of European schoolchildren had easy access to TS.3 The current study further identified that the perceived easy availability of TS significantly increased the odds of misuse, with boys having nearly seven times higher odds and girls nearly five times higher odds compared with those perceiving access as impossible. An ESTUDES 2004–2014 study reported that easy availability increased the odds of misuse by 2.9 times.1 The Estonian ESPAD questionnaire currently assesses the ease of accessing TS; however, it does not include a question regarding the source of these medicines among adolescents. Several studies have found that nearly half or over half of young people who misused TS received them from family members or peers.3 28 29 46 47 The current study revealed a significant association between TS misuse and having friends who also misuse these drugs. Adolescents with a high number of friends misusing TS had substantially higher odds of engaging in TS misuse themselves. Previous studies have consistently demonstrated that friends’ TS misuse substantially increases the odds of individual misuse.3 29 The influence of friends’ TS misuse can be attributed to various factors, including the availability and normalisation of misuse among peers. Additionally, friends may exert pressure to misuse TS, although this pressure tends to decrease with increasing age.48 The strong association between an individual’s misuse and friends' TS misuse is consistent with the finding, where obtaining TS from friends is the most common source.3 28 49 50

Given the increasing ease of availability and the rising prevalence of TS misuse among Estonian adolescents, future additions to the Estonian ESPAD questionnaire could include questions about the source of these medicines to gain insight and implement effective measures, including parental education, to limit availability. Also, it is important to add questions regarding the underlying motivations for TS misuse, as understanding these motives could serve as a potentially modifiable factor guiding screening and intervention efforts aimed at mitigating TS misuse. A US study based on data from 2015 to 2018 revealed that motives for TS misuse varied across age groups, with adolescents (aged 12–17 years) demonstrating the highest prevalence of recreational motives. Notably, recreational misuse was associated with the highest odds of substance use, mental health issues and physical health correlates. Therefore, TS misuse warrants comprehensive screening for substance use and mental health, with intervention strategies being particularly crucial for individuals exhibiting any recreational motives.51

The study demonstrated a strong association between TS misuse and medical use of TS, with significantly increased odds of misuse in both boys (nearly sevenfold) and girls (almost fivefold). Similarly, among adolescents who reported medical use of TS, in 2019, 41.4% of boys (21.1% in 2003) and 44.1% of girls (40.7% in 2003) also reported misuse of these drugs. A study based on the ESPAD 2003 found that adolescents who reported medical use of TS had significantly higher odds of misuse (10.7 times higher for boys and 7.2 times higher for girls), and 30.4% of girls and 25.9% of boys also reported misuse.3 A US study conducted 2007–2011 revealed that 59.4% of students who had used benzodiazepines on doctor’s order had also misused TS.28 These findings highlight the need for healthcare professionals to exercise caution when prescribing TS to young individuals.52 The common use of TS for medical purposes may contribute to their availability and the normalisation of misuse. Young people may perceive TS as safe substances and may be more likely to misuse them,53 especially if they have used them for medical reasons in the past.29 Studies in the USA and the UK indicate that around 30% of TS misusers have previously obtained these drugs through medical prescriptions.9 14 These findings highlight the importance of reviewing prescription practices and implementing digital systems to enhance monitoring and regulation, ensuring appropriate use and preventing misuse.

In addition to the aforementioned characteristics, the misuse of TS was found to be associated with cigarette smoking and cannabis use (only among boys) in this study, while no significant association was found with alcohol use. Boys who smoked cigarettes, whether casually or daily, had nearly double the odds of misusing TS. Among girls, daily smoking increased the odds by nearly 1.5 times. Cannabis use in the past 30 days increased the odds of TS misuse for boys by 1.7 times. Studies based on the ESPAD 2003 and ESTUDES 2004–2014 data found that cigarette smoking in the past 30 days increased the odds of TS misuse by about 1.3 times.1 3 Several studies have consistently shown that the misuse of TS is associated with the use of other legal and illegal substances.5 47 51 54–56 The findings highlight the interconnectedness of substance misuse behaviours and the need for comprehensive approaches to address multiple risk factors simultaneously.

The study findings revealed that exercising less frequently, compared with daily sports, increased the odds of TS misuse by 1.4 times. No additional studies exploring an association between sports activities and TS misuse were identified. Further research is needed to explore the relationship between leisure time activities and TS misuse in greater depth.

This study has certain limitations that warrant consideration. First, the ESPAD survey is conducted as a cross-sectional study, thereby causal inferences could not be made. Moreover, the findings are based on self-reported measures, which may introduce reporting bias and under-reporting of sensitive health-related data. Additionally, the study focused on adolescents aged 15–16 years in Estonia, limiting the generalisability of the results to other age groups. Generalising the study’s results to all adolescents aged 15–16 years old should be done cautiously, as responses were collected only from those present in the classroom on the survey day. The potential influence of the responses from students who were absent on the study’s results remains uncertain. Another notable limitation of the study is that the ESPAD questionnaire only captured information on lifetime misuse of TS, making it impossible to evaluate the misuse of these substances within the past year or 30 days. Consequently, comparing the findings with other studies that examine TS misuse within different timeframes becomes challenging. The US NSDUH studies provide TS misuse estimates based on TS use in the previous 12 months to ensure accuracy and to avoid overestimation. This approach is based on the notion that if a student has not misused TS for a year or longer, they are no longer considered at risk.9 Therefore, assessing TS misuse solely within a lifetime framework in the current study may have led to an overestimation of misuse, as it includes adolescents who may have experimented with TS only once, possibly years ago. Furthermore, the study’s limitation lies in its exclusive focus on assessing TS misuse as the use of TS without a prescription or doctor’s authorisation, without exploring whether TS was used more frequently, in higher doses, to induce intoxication, etc., despite the diverse and complex nature of misuse.11 43 44 Consequently, this limitation may have resulted in an underestimation of TS misuse. The lack of information on common uses of TS medication in the ESPAD survey is another limitation, as adolescents’ possible lack of knowledge with medication names may have resulted in under-reporting of TS misuse. The strength of the survey lies in the consistent methodology employed by ESPAD across multiple years and various countries, enabling a comprehensive investigation of long-term trends within and across different nations. Moreover, the study benefits from a robust sample size and high response rates, enhancing the reliability of data obtained from adolescents aged 15–16 years old in Estonia, although not fully representative of the entire population within this age group.

In conclusion, this study provides valuable insight into the concerning rise of TS misuse among Estonian adolescents between 2003 and 2019, highlighting a significant increase in misuse among both genders, with girls being more likely to misuse these drugs. Compared with other European countries and the USA, Estonia exhibits higher rates of TS misuse, indicating the need for targeted interventions and preventive measures, including gender-based approaches.

Medical use of TS and perceived easy access to TS were identified as strong predictors of misuse, emphasising the importance of cautious prescribing practices, careful monitoring of medical use of TS and stricter regulations to limit availability. Social factors, such as friends’ TS misuse, emphasised the need for interventions promoting positive peer relationships and discourage TS misuse among adolescent social circles. Additionally, TS misuse was associated with other risk behaviours, highlighting the importance of addressing multiple risk behaviours and promoting healthy lifestyles.

Collaboration among policymakers, healthcare professionals, educators and parents is crucial to implement preventive measures and responsible prescription practices. Stricter regulations, enhanced monitoring systems and targeted interventions can help mitigate the adverse effects of TS misuse on Estonian adolescents’ health and well-being.