top of page
  • Writer's pictureJulie de Vaan

Effective Behavioral Interventions for Alcohol Prevention and Substance Use

Updated: Jul 21, 2023

GGD Hart voor Brabant, GGD Zuid-Holland Zuid



  • How can local Public Health Services (GGD's) better reach and motivate parents to adhere to the NIX18 rule using nudging and behavior influence?


  • To answer this question, we will initiate a process to identify the important drivers for parents, the behavioral interventions that target those drivers, and how effective these interventions are in practice.


  • This yields several useful and demonstrably effective interventions to better reach and motivate parents to adhere to the NIX18 rule.



In 2014, the legal drinking and smoking age in the Netherlands was raised to 18 years. The aim of this "NIX18" rule is to limit health damage caused by substance use. According to Trimbos Institute, NIX18 primarily targets parents and caregivers as they have a significant influence on their children's substance use.

The GGD (Public Health Service) aims to raise awareness among parents about the dangers of substance use among young people. The long-term, nationwide NIX18 campaign focuses mainly on education and information. However, local GGDs have noticed that parents are often challenging to reach, and not everyone is willing or able to adhere to the NIX18 rule.

Therefore, the local GGD's GGD Zuid-Holland Zuid (GGD ZHZ) and GGD Hart voor Brabant (GGD HvB) are using our expertise in nudging and behavior influence to determine how they can better reach and motivate their target audiences.


To address this question, we are conducting a process to identify the important drivers for parents, the behavioral interventions that target those drivers, and how effective these interventions are in practice. Understanding why people exhibit certain behaviors allows for more targeted interventions, increasing the likelihood of success by addressing the underlying motivations.

We first investigate why parents either accept or reject the NIX18 rule. This examination also considers specific regions, as small differences between regions can be crucial for the success of interventions. The research includes:

  • An extensive literature review of (behavioral) scientific studies, expert insights, audience research, and learnings from pilots and best practices.

  • 60 in-depth interviews with parents, young people, professionals from the field, and healthcare professionals in the area of substance use.

  • Study and observation of existing interventions such as educational programs and presentations.

  • A questionnaire amongst 131 parents and young people.

These are the main insights from this research:

There are several important factors that determine whether parents adhere to the NIX18 rule. These are:

  • Social influence: "If other parents do not follow the NIX18 rule, then I won't do it either..."

  • Perceived lack of benefit: "...because it won't make a difference anyway."

  • Fear of social exclusion and peer pressure: "...because then my child won't fit in."

  • Sense of unfairness: "I drink myself too," "I was already drinking when I was 16."

  • Sense of control: "If I let my child drink [at home, at the soccer club, at a wedding of..., when I'm present, etc.], at least they won't do it secretly," "...then they can get used to it."

And these are the reasons why parents are or are not receptive to information about substance use and prevention:

  • Fear of judgment: "If I accept help, people might think there is a problem," "...that I can't handle it myself."

  • Desire for independence and their own parenting style: "I don't want help with raising my child because I decide my own parenting style."

  • Skepticism towards others: "I'm not sure if others understand my situation well," "...have my and my children's best interests at heart."

These last factors were found to play a much more significant role in some regions than in others.

Thanks to the research, we now understand why parents are or are not open to NIX18. Based on these insights, we develop several interesting interventions and nudges that target these (often unconscious) drivers and decision-making processes of parents. We test these interventions in practice, and the results of these pilots show which nudges and interventions are most suitable for reaching and motivating parents to adhere to the NIX18 rule.


This approach yields several highly useful and demonstrably effective interventions:

1. Board Game

GGD alcohol prevention and substance use interventions / nudges behavioral change

A board game in which parents discuss NIX18-related challenges together during parent meetings. For example, how do other parents perceive NIX18? What can parents do if other parents decide not to follow the NIX18 rule? How can parents counteract peer pressure? These questions are answered while playing the game, unconsciously targeting the key drivers: social influence, perceived benefit, fear of social exclusion, and sense of control.

The effect? This intervention is tested with 11 parents in 2 different pilots. While playing the game, parents realize that they largely share the same thoughts about NIX18 and face similar challenges. They discuss solutions together and receive valuable tips and tricks to implement the NIX18 rule.

After the game, all parents indicate that they find it enjoyable, educational, and useful. They appreciate that the game encourages reflection, conversation, and discussion, and that they can take away practical information. Parents' feedback includes comments such as:

"Fun and meaningful to have conversations with other parents." "Interesting, informative, makes you think." "Pleasant and open atmosphere. We learned from each other, although our opinions were almost the same." "Well-designed game. A good way to think and discuss such a sensitive topic."

2. Quiz and Theme Meeting

GGD alcohol prevention and substance use interventions / nudges behavioral change

A quiz that helps parents identify their parenting style. This quiz is followed by a theme meeting at school, led by experts in prevention and substance use. During this meeting, parents engage in discussions with like-minded parents, reducing the fear of judgment from parents with different parenting styles and receiving more practical tips that align with their own parenting style. This addresses skepticism and the need for independence.

The effect? Parents who attended the theme meeting found the group discussions very informative, valuable, and helpful. As the information they receive aligns with their parenting style, they feel more empowered to take action. Parents also feel better understood and heard.

However, the turnout for the theme meeting was low and selective: there were few parents attending, and those who did mostly fell into the profile of "the caring multitasker." This means that parents who are typically difficult to reach are still not effectively reached by this intervention.

3. Talking Jar

A "talking jar" filled with questions, information, and tips about parenting and substance use. Youngsters receive the jar from school and can use it to initiate conversations with their parents about parenting and topics such as alcohol, smoking, and drugs in a safe environment, behind closed doors, and at their own pace.

4. School Assignment

GGD alcohol prevention and substance use interventions / nudges behavioral change

A school assignment where youngsters are asked to interview their parents about parenting and NIX18. This encourages them to have conversations with their parents. As the child takes on the role of the interviewer during the conversation, parents have the opportunity to calmly explain their perspective on NIX18, and young people learn to understand their parents' perspective.

The effect? These interventions reduce skepticism and fear of judgment. Parents become more open to discussions about parenting and NIX18 because their children initiate and guide these conversations. Both parents and their children indicate that they find it important to talk about these topics with each other.

The school assignment's effect and reach are the greatest. Based on approximately 90 evaluations from parents, it motivates them to adhere to the NIX18 rule. Especially parents who don't usually talk much with their children about alcohol, smoking, and drugs find the school assignment valuable. Stijn Creugers from the GGD also states: "Parents, children, and schools responded enthusiastically, and from the conducted interviews, we reached other parents than before. The most important conclusion - after analyzing about 90 completed evaluation forms - is that the school assignment leads parents to be more inclined to follow the NIX18 rule."

The GGD finds all the other interventions useful as well and intends to further develop and implement these nudges. Moreover, the GGD is convinced of the potential of nudging and plans to use it more broadly. Marita, Public Health Advisor at the GGD, also states: "Nudging appears to be an interesting option to achieve behavioral change."

bottom of page