The present study illustrates the pathway linking health-risk behaviours with demographic and socioeconomic factors. The findings indicate that nearly one in two underage school students had had at least one alcoholic drink in the previous month, that one in four smoked, nearly 1 in 5 had consumed cannabis in the previous year and 1 in 15 could be defined as an at risk or problem gambler. These prevalence data are consistent with previous research.24 The particular geographical distribution of the ORs for the prevalence of different health-risk behaviours in Italy was also in line with official records.25 26

On the associations between different types of health-risk behaviour, this study highlighted that gambling is associated with alcohol and cannabis consumption, even after controlling for socioeconomic and demographic factors. The higher prevalence of multiple health-risk behaviours among young gamblers is a commonly recognised problem.27 For instance, data from a US sample of 2274 young people aged 14 –21 years showed that alcohol, tobacco and marijuana use and conduct disorder are strong independent predictors of gambling.27 This supports the concept that substance abuse and gambling behaviour are part of a more general problem behaviour syndrome associated with conduct disorder.27 This concept suggests that, as one type of adolescent problem behaviour increases, the likelihood of other problem behaviours developing increases too, and the co-occurrence of problem behaviours suggests that they have antecedent explanatory factors in common.27 The tendency of some adolescents to adopt multiple health-risk behaviours could be explained by the ‘gateway hypothesis’,28 29 according to which an adolescent’s early experimentation with alcohol or tobacco or cannabis can escalate to more addictive illicit drug use.30

As regards the economic factors, a higher weekly income was positively associated with all the health-risk behaviours considered in this study, with the exception of cannabis consumption. Consistently with this finding, a New Zealand survey on a sample of secondary school students of the same age as our sample (14–17 years old) revealed that the proportion of students with part-time jobs, and consequently more money, was associated with a greater consumption of alcohol, cigarettes and gambling.31 These results suggest that having access to more money could increase an adolescent’s chances of engaging in health-risk behaviours.31 In fact, previous research found that demand for substances is price-sensitive:32 33 following the demand model for goods and services, adolescents with higher disposable incomes could also be at higher risk of substance use because they have more financial resources to purchase alcohol34 or other addictive substances.35 36 It would be worth considering intervention designed to provide young people with guidance on the use of their discretionary income,31 alongside approaches that steer parents to limit the amount of money they give to their children unless they have a clear picture of how it is being spent.

Our study also revealed that economic dissatisfaction was associated with alcohol, smoking and cannabis use, but not with gambling behaviour. In line with our results, a meta-analysis37 on marijuana and alcohol use by SES in adolescents aged 10–15 years found that the prevalence of marijuana and alcohol consumption was 22% higher in adolescents with a lower SES than in those with a higher SES. A possible explanation for this could come from strain theory,38 according to which coming from a relatively poor family (like failing at school) can be as a source of dissatisfaction that promotes potential health-risk behaviour, including substance use, as a way to gain respect when ordinary social valuations are impossible.39 In the light of these findings, it would be desirable for public health prevention strategies to focus most on the more deprived populations in order to prevent the spread of social inequalities, which might even be further aggravated by untargeted prevention schemes.

As for the social context, this study found maternal employment positively associated with alcohol and cannabis consumption and smoking in adolescence. A possible explanation for this could lie in that working mothers generally spend less time at home and might monitor their children less effectively. Previous studies have shown an increased risk of tobacco and alcohol use among adolescents who experience less parental supervision due to their absence from home.40 In fact, parental monitoring, which incorporates parent-youth communication, and youth supervision by parents or guardians, seems to be especially influential in its association with adolescent involvement in health-risk behaviours, both delaying the onset of such behaviours among naive adolescents, and containing them among adolescents already practicing them.41 42

Our study highlighted a major risk of smoking in adolescents who had experienced a parent’s death. Other authors43 examined the impact of exposure to family adversity (including parental death, parental conflict, parental absence from home and divorce) on the timing of smoking initiation, using data from a longitudinal panel study. The four types of family adversity examined were all associated with a higher risk of smoking, but losing a parent had the greatest impact on the initiation of smoking. There is substantial evidence of these adverse experiences having a deleterious impact on a child’s developmental, behavioural, psychosocial and physical outcomes.44 Adolescents, in particular, may try substance use in an effort to cope with their stress, as posited by stress-coping theory.45 In parallel, social learning theory suggests that people who face more adversity tend to have parents or close friends who are themselves substance users46 47 and are consequently at higher risk of substance use themselves.

The findings of this study emphasise the fact that health-risk behaviours are more likely in population subgroups characterised by certain socioeconomic variables. It would therefore be useful to design selective prevention measures (programme designed for at risk groups) as well as the recommended universal approaches (programme designed for overall target population such as students) and indicated ones (programmes designed for people who are already experimenting with drugs).48 A good example of a successfully implemented prevention scheme is the Adolescent Transitions Program (ATP):49 this is a school-based programme that uses a tiered approach to provide prevention services for students in middle school and junior high school and their parents. A general intervention, intended for parents of all students in a school, establishes a Family Resource Room to engage parents, establish norms for parenting practices and disseminate information about the risks of problem behaviour and substance use in adolescence. A selective intervention level, called the Family Check-Up, offers family assessments and professional support to identify families at risk of problem behaviour and substance use. The indicated level, the Parent Focus curriculum, provides direct professional support to help parents make the changes indicated by the Family Check-Up. The services may include behavioural family therapy, parenting groups or case management services.48 The longitudinal effects of the ATP through middle school and the first year of high school have been analysed and shown that random assignments to the school-based ATP were associated with a lower incidence of substance use by the first year of high school, even after controlling for prior substance use in middle school.49