At Risk for Criminal BehaviorMMheenNCT07147738
The Effectiveness of a Dutch Prevention Program on Social-emotional Skills and Juvenile Delinquency in Children
A study testing Kapot Sterk (translate as Incredibly Strong) in people with At Risk for Criminal Behavior, run by Marit van de Mheen at 1 site in Netherlands.
Trial summary
The purpose of this study is to investigate whether the prevention program Kapot Sterk is effective. Read more about this study
- Who is it for?
- Ages 10 to 13 years
- Conditions the study is for
- At Risk for Criminal Behavior
- What is being tested?
- Kapot Sterk (translate as Incredibly Strong)
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 286 participants
- Where
- 1 siteNetherlands
- Study dates
- 20 Nov 2024to 26 Sep 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 10 to 13 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Every pupil who meets the inclusion criteria for the intervention program can participate in the study. The program is for pupils in their last or second-to-last year of elementary school.
- Participants are 10-13 years old.
- Participants attend school.
Who cannot join
- Participants are younger than 10 years old or older than 13 years old.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effectiveness of a Dutch School-based Prevention Program on Social-emotional Skills and Juvenile Delinquency in Children: A Randomized Controlled Trial
The purpose of this study is to investigate whether the prevention program Kapot Sterk is effective.
Read the detailed description
Given the growing concerns about youth's involvement in criminal behavior, there is a strong need for effective interventions to prevent it. However, knowledge about the effectiveness of prevention programs for juveniles is currently lacking. Incredibly Strong (translate as Kapot Sterk) is a prevention program designed to improve self-esteem, self-control, and resistance to peer pressure among pupils in elementary schools. By enhancing these social-emotional skills, the program ultimately aims to reduce youths' vulnerability to recruitment and involvement in criminal activities. The effects of Incredibly Strong on juvenile delinquency and other life domains are investigated, using a randomized controlled trial (RCT).
- Conditions
- At Risk for Criminal Behavior
- Being tested
- Kapot Sterk (translate as Incredibly Strong)
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Kapot Sterk (translate as Incredibly Strong)Behavioural
The program consists of five lessons of approximately 60 minutes long, delivered over a period of four to eight weeks. The lessons are facilitated by trained pedagogical staff (e.g., youth workers), while the school's own teachers are always present during the sessions. Lessons include active learning strategies such as role-playing, group discussions, and reflection exercises, often based on realistic and recognizable scenarios. The program focuses on strengthening key social-emotional skills, such as self-esteem, self-control, and resistance to peer pressure.
| Study group | Role | What they receive |
|---|---|---|
| experimental group | Experimental | This group will participate in the program Kapot Sterk. Receives: Behavioral: Kapot Sterk (translate as Incredibly Strong) |
| control group | No intervention | This group will not participate in the program. They will receive the program afterwards, once data collection is finished. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Self-esteem
will be measured using an instrument based on items from the Dutch version of the Rosenberg Self-Esteem Scale (RSES), developed for a study with children aged 8-12 years. The instrument contains five items (e.g., "I think positively about myself"), rated on a 3-point scale ranging from 1 (not true) to 3 (definitely true). Higher scores reflect greater self-esteem.
Measured: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
Self-control
will be measured using five items based on the Brief Self-Control Scale (Tangney et al., 2004) (e.g., "I am good at saying no to things that are hard to resist"). Items are rated on a 5-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree). Items 3 and 4 will be reverse coded so that higher scores reflect higher self-control.
Measured: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
Peer pressure
will be measured using ten items based on the Peer Pressure Scale (Sullivan, 2006). The original items have been translated into Dutch and adapted to reflect minor offenses typically committed by juveniles (e.g., "I feel pressure from my friends to steal something from a shop"). Items are rated on a 5-point Likert scale ranging from 1 (absolutely never) to 5 (very often). Higher scores indicate greater levels of experienced peer pressure.
Measured: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
Secondary outcomes (3)
Externalizing behavior
will be measured using the externalizing behavior and delinquency subscales of the Youth Self-Report (YSR) (Verhulst \& Van der Ende, 1992). The instrument focuses on various externalizing behaviors, including aggression and delinquent behavior. The YSR includes items such as "I fight a lot", which are rated on a 3-point Likert scale ranging from 0 (never) to 2 (often). Higher scores on the YSR externalizing subscale indicate greater levels of externalizing behavior.
Measured: baseline (T0) and at 3 months post-program (T2).
Perceived social support from parents, friends, and significant others
will be measured using the 12-item Multidimensional Scale of Perceived Social Support (MSPSS) (Zimet et al., 1990). Participants rate statements such as "I have a special person who is a real source of comfort to me" and "I can talk about my problems with my family" on a 5-point Likert scale (1 = very strongly disagree to 5 = very strongly agree). Higher scores indicate greater levels of experienced support.
Measured: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
Knowledge of youth work
will be assessed using four questions. Participants are first asked, "How well do you know what youth work is?" Those who respond with "well" or "a little" are then prompted to describe, in their own words, what youth workers do. A similar procedure is followed for the question "How well do you know where to find youth workers?" Participants who indicate some level of knowledge are asked to specify where youth workers can be found.
Measured: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Aug 2025
- Study start20 Nov 2024
- Primary completion26 Sep 2025
- Study completion26 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for At Risk for Criminal BehaviorStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- A cluster RCT will be used to determine the effectiveness of the program Incredibly Strong. Within each school, classes will be randomly assigned to either the experimental group, in which the program starts as soon as possible, or to a waitlist control group, which starts after the follow-up period (three months). Randomization to either the experimental or control group will take place using a computerized randomization in a 1:1 ratio. Classes in the waitlist control group receive the program approximately 5 months later, but still within the same school year, allowing all classes to receive the program.
- Masking
- None (open label)
- Enrolment
- 286 participants (actual)
Sponsor and investigators
- Lead sponsor
- Marit van de Mheen
- Sponsor type
- University, hospital or other
- Collaborators
- Netherlands Institute for the Study of Crime and Law Enforcement, VU University of Amsterdam
- Responsible party
- Sponsor-investigator, Marit van de Mheen, Utrecht University
- Investigators
- Jessica J Asscher, PhD., Principal investigator, Utrecht University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07147738
- Sponsor's protocol ID
- 1434.201.001
- Acronym
- MMheen
- Status last verified
- Jul 2026
- First submitted
- 15 Aug 2025
- Last updated
- 14 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: The data can be shared in anonymized form upon request.
Study at a glance
From the registry record, last updated by the sponsor on 14 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effectiveness of a Dutch School-based Prevention Program on Social-emotional Skills and Juvenile Delinquency in Children: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07147738
- Acronym / sponsor ID
- MMheen / 1434.201.001
- Conditions
- At Risk for Criminal Behavior
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 286 participants (actual)
- Lead sponsor
- Marit van de MheenUniversity, hospital or other
- Collaborators
- Netherlands Institute for the Study of Crime and Law Enforcement, VU University of Amsterdam
- Study start
- 20 Nov 2024 (actual)
- Primary completion
- 26 Sep 2025 (actual)
- Study completion
- 26 Sep 2025 (actual)
- First posted
- 29 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to investigate whether the prevention program Kapot Sterk is effective.
Detailed description
Given the growing concerns about youth's involvement in criminal behavior, there is a strong need for effective interventions to prevent it. However, knowledge about the effectiveness of prevention programs for juveniles is currently lacking. Incredibly Strong (translate as Kapot Sterk) is a prevention program designed to improve self-esteem, self-control, and resistance to peer pressure among pupils in elementary schools. By enhancing these social-emotional skills, the program ultimately aims to reduce youths' vulnerability to recruitment and involvement in criminal activities. The effects of Incredibly Strong on juvenile delinquency and other life domains are investigated, using a randomized controlled trial (RCT).
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- A cluster RCT will be used to determine the effectiveness of the program Incredibly Strong. Within each school, classes will be randomly assigned to either the experimental group, in which the program starts as soon as possible, or to a waitlist control group, which starts after the follow-up period (three months). Randomization to either the experimental or control group will take place using a computerized randomization in a 1:1 ratio. Classes in the waitlist control group receive the program approximately 5 months later, but still within the same school year, allowing all classes to receive the program.
| Arm | Type | Receives |
|---|---|---|
| experimental group | Experimental | Behavioral: Kapot Sterk (translate as Incredibly Strong)This group will participate in the program Kapot Sterk. |
| control group | No intervention | –This group will not participate in the program. They will receive the program afterwards, once data collection is finished. |
Who may qualify
- Ages
- 10 to 13 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (3 listed)
- Every pupil who meets the inclusion criteria for the intervention program can participate in the study. The program is for pupils in their last or second-to-last year of elementary school.
- Participants are 10-13 years old.
- Participants attend school.
Key exclusion criteria (1 listed)
- Participants are younger than 10 years old or older than 13 years old.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Kapot Sterk (translate as Incredibly Strong)The program consists of five lessons of approximately 60 minutes long, delivered over a period of four to eight weeks. The lessons are facilitated by trained pedagogical staff (e.g., youth workers), while the school's own teachers are always present during the sessions. Lessons include active learning strategies such as role-playing, group discussions, and reflection exercises, often based on realistic and recognizable scenarios. The program focuses on strengthening key social-emotional skills, such as self-esteem, self-control, and resistance to peer pressure. | Behavioural | experimental group |
Primary outcome
Self-esteem
Time frame: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
will be measured using an instrument based on items from the Dutch version of the Rosenberg Self-Esteem Scale (RSES), developed for a study with children aged 8-12 years. The instrument contains five items (e.g., "I think positively about myself"), rated on a 3-point scale ranging from 1 (not true) to 3 (definitely true). Higher scores reflect greater self-esteem.
Self-control
Time frame: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
will be measured using five items based on the Brief Self-Control Scale (Tangney et al., 2004) (e.g., "I am good at saying no to things that are hard to resist"). Items are rated on a 5-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree). Items 3 and 4 will be reverse coded so that higher scores reflect higher self-control.
Peer pressure
Time frame: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
will be measured using ten items based on the Peer Pressure Scale (Sullivan, 2006). The original items have been translated into Dutch and adapted to reflect minor offenses typically committed by juveniles (e.g., "I feel pressure from my friends to steal something from a shop"). Items are rated on a 5-point Likert scale ranging from 1 (absolutely never) to 5 (very often). Higher scores indicate greater levels of experienced peer pressure.
3 secondary outcomes
Externalizing behavior
Time frame: baseline (T0) and at 3 months post-program (T2).
Perceived social support from parents, friends, and significant others
Time frame: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
Knowledge of youth work
Time frame: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Jul 2026.
- Individual participant dataSharing planned: Yes. The data can be shared in anonymized form upon request.
Related trials for At Risk for Criminal Behavior
Recruiting
Changing Lives and Changing Outcomes-9 at Worcester Recovery Center and Hospital
Serious Mental Illness, Psychotic Disorder
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jessica J Asscher, PhD. principal investigator
Utrecht University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Kapot Sterk (translate as Incredibly Strong) in people with At Risk for Criminal Behavior, run by Marit van de Mheen at 1 site in Netherlands.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Self-esteem (time frame: baseline (T0), immediately after the program ended for the intervention group (or after the waiting period for the control group) (T1), and at 3 months post-program (T2).). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Jul 2026.