Netherlands

Moti-4 has been evaluated in one randomized controlled trial in the Netherlands for cannabis usage (Dupont et al., 2016) and there is one pilot study on the effects of Moti-4 on problematic gambling or gaming behaviour (Dupont et al. 2015).

In the RCT (Dupont et al., 2016) a wide array of young adults aged 14-24 years were eligible to participate in Moti-4. This study showed that Moti-4 had a significant positive influence on the indirect measure of money. The stated weekly spend on cannabis was reduced (between T0 and T1 (post-test) p = 0.002; between T0 and T2 (6-month follow-up) p = 0.007). The number of joints smoked weekly was also reduced significantly after six months compared to baseline (p = 0,004). There was no significant reduction concerning weekly smoked joints found directly after the intervention (between T0 and T1, p = 0.932). This study suggests that Moti-4 can be an effective intervention to reduce cannabis use in youth at the 6-month follow-up, but did not include a 12-month follow-up.

The programme has been evaluated in one cluster-randomised trial (RCT) and in one quasi-experimental design in The Netherlands. An adapted version for special education students was studied in a quasi-experimental trial.

The first evaluation study (QED) (Cuijpers et al. 2002) enrolled five regions of municipal health services in the Netherlands. In order to be included in the study, schools had to have an active committee coordinating the drug prevention activities at the school. Students of nine experimental (N = 1156) schools were compared with students of three control schools (N = 774). The groups were compared before the intervention started, 1 year later, 2 years later and 3 years later. The primary outcomes were self-reported frequency of and lifetime use of tobacco, alcohol and marijuana. Two years after the start of the intervention, only effects on alcohol use were found. There was no clear evidence for any effects on attitude towards substance use and on self-efficacy. A secondary analysis studied differential effects in various segments of the student population (Smit et al., 2003). Multivariate logistic regression analysis showed that the effect of the intervention on alcohol use was less favourable in students who disliked school.

The RCT (Malmberg et al. 2014) studied two intervention conditions: the integral programme compared to a limited e-learning module. Structured digital questionnaires were administered pre-intervention and at 32 months follow-up. The primary outcome measures were new incidences of alcohol (life-time and 1-month prevalence), tobacco (life-time and 1-month prevalence) and marijuana use (life-time prevalence). There were no statistically significant intervention effects on any outcome. The study concluded that the programme was either ineffective or implemented inadequately. A secondary analysis (Malmberg et al. 2015) explored whether boys, adolescents of lower educational backgrounds, or adolescents high on personality risk traits would benefit more from the HSD program than others. The results showed that sex, education level and personality characteristics of the participants did not moderate the intervention effects.

A QED (Turhan et al. 2017) aimed at studying HSD’s effectiveness on tobacco and alcohol use in Dutch secondary special education (SE) schools, and whether this depends upon subtypes of SE schools and the level of implementation. Thirteen secondary SE schools spread throughout the Netherlands participated. 363 students were allocated arbitrarily or depending on teacher motivation to either intervention condition (n = 205) or usual curriculum (n = 158). There was no clear evidence for any effects on attitude towards substance use or self-efficacy. While no effects of HSD-SE were found for SEL (learning disabilities/developmental disorders) students, significant adverse effects were found in SEB student (behavioural/emotional difficulties) on both a cognitive and a behavioural alcohol-related outcome measure. SEB students distinguish themselves from SEL students in displaying more oppositional and defiant behaviour, leading to counteracting peer interactions during class. The pilot study concluded that within special education, substance use interventions may need to be targeted at school subtypes, as these may have harmful effects among students with behavioural difficulties.

Although HSD includes a parent component (conference providing parenting skills specifically relevant for preventing alcohol and tobacco use) this is not evaluated in any of the above studies. Nevertheless, Koning et al. 2009 demonstrated in a RCT that combining only the alcohol module of the HSD (student component) programme with a brief parental meeting (parent component) that was integrated in an existing general parents’ meeting at the beginning of each school year (year 1, 2 and 3 in high school) was effective. That is, onset of weekly drinking was postponed up to 52 months after baseline through an increase in strict rule-setting about alcohol and adolescents’ level of self-control. The student only or parent only components were not effective. This was different from the original HSD program in three ways 1) only alcohol use was a target, 2) parents meeting was integrated in general parents meeting which yielded high attendance rates and 3) a school committee, regulations and early detection were not included., in which parental rule-setting behaviour was encouraged as an effective strategy, helped to reduce adolescents’ alcohol use. The latter study was not included in the Xchange evaluation because it is not considered the core of the HSD programme.

The effect of changing bar closing hours have been studied in experimental evaluation designs in Norway (Rossow et al. 2012) and The Netherlands (De Goeij et al., 2012). Conducting an RCT is not possible because of the environmental nature of these measures.

Rossow and colleagues (2012) estimated the effect on violence of small changes in closing hours for on-premise alcohol sales and assessed whether a possible effect is symmetrical. The study demonstrated that each additional 1-hour extension to the opening times of premises selling alcohol was associated with a 16% increase in violent crime. The quasi-experimental evaluation study drew on data from 18 Norwegian cities that extended or restricted the closing hours for on-premise alcohol sales with a maximum of 2 hours. Closing hours were measured in terms of the latest permitted hour of on-premise trading, ranging from 1 a.m. to 3 a.m. The outcome measure comprised police-reported assaults that occurred in the city centre between 10 p.m. and 5 a.m. at weekends. Assaults outside the city centre during the same time window functioned both as a proxy for potential confounders and as a control variable. The data spanned a period of ten years (2000–2010) and included 774 observations. Outcomes from the main analyses suggested that each 1-hour extension of closing hours was associated with a statistically significant increase of 4.8 assaults (95% CI 2.60, 6.99) per 100 000 inhabitants per quarter (i.e. an increase of about 16%). Findings indicate that the effect is symmetrical (extending or restricting). These findings were consistent across three different modelling techniques.

De Goeij and colleagues (2015) studied the implementation of a new alcohol policy in Amsterdam allowing alcohol outlets in two of the five nightlife areas to extend their closing times from 1 April 2009 onwards. The study found that a 1-hour extension of alcohol outlet closing times in some of Amsterdam’s nightlife areas was associated with 34% more alcohol-related injuries. They investigated how levels and trends of hospital reported alcohol-related injuries changed after implementation of this alcohol policy by comparing areas with extended closing times to those without. A before-and-after evaluation compared changes in alcohol-related injuries between intervention and control areas. Participant alcohol-related ambulance attendances were compared between control and intervention areas between 1 April 2006 and 1 April 2009 (respectively n=544 and n=499) and between 1 April 2009 and 1 April 2011 (respectively, n=357 and n=480). The results demonstrate that after 1 April 2009, intervention areas showed a larger change in the level of alcohol-related injuries than control areas [incidence rate ratio 1.34, 95% confidence interval (CI) =1.12, 1.61], but trends remained stable in all areas. This increase was only statistically significant for the following subgroups: 2.00–5.59 a.m., weekend days, men, individuals aged 25–34 years, and people transported to a hospital. However, the increase did not differ between subgroups with statistical significance.

The programme has been evaluated in randomized controlled trials in Finland (2007), the United Kingdom (2020), the Netherlands (2020), and Italy (2016). Evaluations are underway in Estonia, Greece, and the UK (Clarkson et al., 2022). The intervention is also implemented in Spain (Lopez-Catalan et al., 2022) and Belgium. The latter two evaluations are not considered in the Xchange rating because of methodological issues
 
KiVa was developed and first evaluated in Finland. Subsequently, two-thirds of all Finnish comprehensive schools started implementing KiVa in 2011. For this first evaluation, 78 schools were randomly assigned to intervention and control conditions. The first phase (2007-2008), with 8237 pupils, aged 10-12 years in Grades 4-6 in 78 schools, demonstrated significant reductions in pupil-reported bullying and victimisation after one academic year (Kärnä et al., 2011). KiVa was found to significantly reduce (by 17-30% in comparison to control schools) both peer- and self-reported bullying and victimization. The odds of being a victim were about 1.5-1.8 times higher and being a bully was 1.2-1.3 times higher for the control group of students than for intervention school students.
 
Reductions occurred in all nine forms of bullying examined including physical, verbal, and cyber-victimisation (Salmivalli et al., 2011). In phase two (2008-2009 with children aged 7-15 years, Grades 1-9) victimisation and bullying were reduced by approximately a third for intervention schools. Increased empathy and self-efficacy in supporting and defending victims, and reductions in bully-reinforcing behaviour were also reported (Salmivalli & Poskiparta, 2012). Furthermore, anxiety and depression decreased, peer perceptions improved (Williford et al., 2012) and school liking, academic motivation, and performance increased (Salmivalli et al.,2012; Clarkson et al., 2019).
 
A secondary analysis of this Finnish data (Garandeau et al., 2022) applied multilevel structural equation modelling analyses in pre-test and post-test (1 year later) data in the same sample (n=15,103, 399 control and 462 intervention classrooms from 140 schools). The study showed that KiVa had a positive effect after nine months on affective empathy, but not cognitive empathy, independent of students’ gender, initial levels of empathy, bullying, or popularity, nor of school type or classroom bullying norms. Analyses conducted in a sample of 5731 children (baseline Mean age = 11 years; 51% girls) (Garandeau et al., 2023) revealed that the positive effects of KiVa on defending behaviour after 9 months of implementation could partly be explained by the positive effects of the program on two factors (i.e., feelings of responsibility to intervene and expectations that the defending would make the bullying decrease or stop) after 5 months of implementation
 
The age group 10-12 years showed the best result in Finland (Unit 2 lesson curriculum) (Kärnä et al., 2011). Indeed, KiVa’s anti-bullying work is more challenging in Finnish secondary than in its primary schools (Kärnä et al., 2013).
 
The Italian RCT (Nocentini & Menesini, 2016) involved 2042 students in grades 4 and 6 (approx. 8 to 11 years old) in 13 randomly assigned school to intervention group (KiVa) and to the control group (usual school provision). The study focused on different outcomes, such as bullying, victimisation, pro-bullying attitudes, pro-victim attitudes, and empathy towards victims. Multilevel models showed that KiVa reduced bullying and victimisation and increased pro-victim attitudes and empathy toward the victim in grade 4, with ES = 0.24 to -.40. In grade 6, KiVa reduced bullying, victimisation and pro-bullying attitudes, the effect was smaller, but also significant (d>= 0.20). The study showed that the odds of being a victim were 1.93 times higher for a control group than for an intervention group.
 
The Dutch RCT (Huitsing, 2020) evaluated KiVa and KiVa+ among 4383 students in grades 3 – 4 (aged 8-9) from 98 schools who volunteered to participate in the research. The study collected outcome data at five-time points over a period of three years. At the baseline, two-thirds of the participating schools were randomly assigned to the intervention group (KiVa or KiVa+, with an additional intervention component of network feedback to teachers) and one-third to the control group (waiting list, case as usual). The study showed that self-reported victimisation and bullying were reduced more strongly in KiVa-schools compared with control schools, and with stronger effects after two school years of implementation. Moreover, it showed that the odds of being a victim were 1.29 – 1.63 times higher for control group, and the odds of being a bully were 1.19 – 1.66 higher than for KiVa students. There were no significant differences between KiVa and KiVa+.
 
The British two-arm waitlist control cluster RCT (Axford et al., 2020) involved 3214 students (aged 7-11) in 22 primary schools. The schools were randomly allocated to the intervention group and waitlist control group (usual school provision) with a 1:1 ratio. The outcomes targeted were student-reported victimisation and bullying perpetration, teacher-reported child behaviour and emotional well-being, and school absenteeism (administrative reports). There was no statistically significant effect on the primary outcome of child-reported victimisation or the secondary outcomes. The impact on victimisation was not moderated by gender, age or victimisation status at baseline. The trial found insufficient evidence to conclude that KiVa affected the primary outcome. The programme has been rated as Promising by Blueprints for Healthy Youth Development based on the review of studies conducted worldwide.

Licensing data were obtained at local level from the Home Office Alcohol and Late Night Refreshment Licensing data and local areas were coded as ‘passive’, low, medium or highly active based on whether they made use of cumulative impact areas and/or whether any licences for new premises were declined. These data were linked to 2009–2015 alcohol-related hospital admission and alcohol-related crime rates obtained from the Local Alcohol Profiles for England. Population size and deprivation data were obtained from the Office of National Statistics. Changes in directly age-standardised rates of people admitted to hospital with alcohol-related conditions were analysed using hierarchical growth modelling.

Stronger reductions in alcohol-related admission rates were observed in areas with more intense alcohol licensing policies, indicating an ‘exposure–response’ association, in the 2007–2015 period. Local areas with the most intensive licensing policies had an additional 5% reduction (p=0.006) in 2015 compared with what would have been expected had these local areas had no active licensing policy in place (De Vocht et al. 2016).

Local areas in England with more intense alcohol licensing policies had also a stronger decline in rates of violent crimes, sexual crimes and public order offences in the period up to 2013 of the order of 4–6% greater compared with areas where these policies were not in place, but not thereafter (De Vocht et al. 2017b).

An experimental design study used Home Office licensing data (2007– 2012) to identify (1) interventions: local areas where both a cumulative impact zone and increased licensing enforcement were introduced in 2011; and (2) controls: local areas with neither. Outcomes were 2009–2015 alcohol-related hospital admissions, violent and sexual crimes, and antisocial behaviour. Bayesian structural time series were used to create post-intervention synthetic time series (counterfactuals) based on weighted time series in control areas. Intervention effects were calculated from differences between measured and expected trends and showed moderate reductions in alcohol-related hospital admissions and violent and sexual crimes associated with introduction of local alcohol licensing policies (de Vocht et al. 2017a).

Using the same analytic methods (Bayesian structural time–series), a paper with three natural experiments in English local areas of 1000–15000 people each evaluated the impact of local licencing interventions at small spatial scale by using a causal inference framework. Interventions were (a) the closure of a nightclub following reviews; (b) closure of a restaurant/nightclub following reviews and (c) implementation of new local licensing guidance (LLG). Data from emergency department admissions, ambulance call-outs and alcohol-related crime at the lower or middle geographical aggregation level showed that a) closure of the nightclub led to temporary 4-month reductions in antisocial behaviour with no change in other outcomes, b) closure of the restaurant/nightclub did not lead to measurable changes in outcomes, while c) the new licensing guidance led to small reductions in drunk and disorderly behaviour (nine of a predicted 21 events averted), and the unplanned end of the LLG coincided with an increase in domestic violence of two incidents per month (De Vocht el al. 2020).

With an inverted design, a study in Brabant, NL (de Goeij et al. 2017) assessed how youth alcohol consumption trends were related to the development and implementation of integrated policies: six municipalities with stronger declines in youth alcohol consumption between 2007 and 2011 (cases) were compared to four municipalities with weaker declines (controls). Information on the policy process in the same period was obtained through semi-structured in-depth interviews with policy advisors and extracted from policy documents. Municipalities with stronger declines in alcohol consumption involved sectors other than public health and had started to implement interventions that use regulatory or enforcement strategies. Their involvement was facilitated by framing youth alcohol consumption as a safety rather than a health problem, whereby local media played a substantial role.

The programme has been evaluated in four randomised controlled trials in the Netherlands and one quasi-experimental study in the UK.

In a cluster randomised controlled trial in the Netherlands, in which schools were randomised, 118 female adolescents, aged 11 to 15 years, with elevated depressive symptoms participated. Depressive symptoms (but not controlling for baseline values) were significantly different between conditions at posttest and 6-month follow-up, but not at 1-month follow-up.

A second cluster randomised controlled trial in the Netherlands, evaluated the programme on a universal prevention level. Secondary schools in which at least 30% of their pupils lived in low-income areas were eligible. 61 classes including 1440 adolescents aged 11-16 were randomly allocated. A latent growth curve approach found the increase or decrease in depressive symptoms across follow-ups did not differ between the intervention and control condition.

Another cluster randomised controlled trial in the Netherlands, evaluating the programme as universal prevention, randomised 9 schools. 1341 adolescents, with a mean age of 13.9 years participated. There was no significant intervention effect on level of depressive symptoms or the number of adolescents with elevated symptoms at posttest, one and two-year follow-ups. An iatrogenic effect was found at post-test, where adolescents in the intervention condition reported less optimism, less active coping, less social self-efficacy and lower school grades; these effects were not sustained at follow-ups.

A randomised controlled trial, randomising individuals, has also been conducted in the Netherlands 208 Dutch female adolescents (mean age 13 years) with elevated depressive symptoms. The study compared Op Volle Kracht against another intervention (SPARX), a combination of Op Volle Kracht and SPARX and a self-monitoring control group, where participants completed questionnaires weekly to monitor their depressive symptoms. There was a significant time effect across conditions, but there were no significant intervention effects. The control group was not a treatment-as-usual or no-treatment control group, and thus the study cannot be considered to provide definite evidence of intervention ineffectiveness.

The English study included 2910 children aged 11 or 12 years at baseline. There was a significant, positive effect of the intervention on depressive symptoms at posttest (but not at one- or two-year follow-up). No significant effects were found for anxiety or behaviour problems at any post-baseline assessment period.

The programme has been evaluated in several cluster randomised controlled trials, two in the UK - one in Northern Ireland (Ross et al., 2011) three in England (Hennessey et al., 2019, 2021; Panayiotou et al., 2020; Humphrey et al., 2015, 2016; Little et al., 2012) – one in Switzerland (Malti et al., 2011, 2012) and one in Sweden (Eninger et al., 2021). There have also been four quasi-experimental studies, one each in Turkey (Seyhan et al., 2017) and the Netherlands (Goossens et al., 2012) and two in the UK (Curtis & Norgate, 2007; Hughes & Cline, 2014).

One UK trial (Little et al., 2012) was conducted with 5397 children aged 4 to 6 years from 29 schools that were randomised to intervention and 27 schools that were randomised to control. Measures were gathered using five scales from the teacher-completed Strengths and Difficulties Questionnaire and nine scales from the PATHS Teacher Rating Survey. Results indicated that while there were some statistically significant improvements in the intervention group compared to the control group at mid-intervention, these improvements disappeared post-test and no statistically significant differences were observed between groups at immediate post-test.

In another UK trial (Humphrey et al., 2015, 2016), 4516 children aged 7 to 9 years from 45 schools, that were randomly allocated to intervention or control, participated. Of the 14 scales, there was a significant positive intervention effect on 1 measure and a significant negative intervention effect on 2 measures. There was a statistically significant increase in teachers' perceptions of change in children's social–emotional competence in the intervention group. A statistically significant effect favouring the control group was found on SDQ peer problems and SDQ emotional symptoms scales.

Hennessey et al. (2019, 2021) and Panayiotou et al. (2020) used the former sample of (45 schools with 5218 school-aged children). Academic performance was measured with a national curriculum assessment for English, Mathematics and Science. The intervention did not show more effectiveness in improving the academic attainment of children compared to the control group. The results concerning loneliness (KIDSCREEN27) revealed a significant positive effect compared to the control group. Psychological wellbeing, peer social support and school connectedness showed a small, but statistically significant improvement after the PATHS intervention at a 2-year follow-up. However, the intervention had no discernible impact on peer social support and school connectedness.

The study from Northern Ireland (Ross et al., 2011) included 1448 students, aged 4 to 10 years, from 12 primary schools that were evenly randomised to intervention or control. Students were from primary 1 and 2, and 5 and 6; some analysis was reported separately for these groups. For primary 1 and 2, there were no significant effects on teacher-reported behaviour. For primary 5 and 6, there were three significant differences between groups, two of which favoured the control group: reflectivity and perseverance. There was a positive intervention effect on negative affect. There were positive intervention effects that were significant on 4 of 11 observed teacher behaviour: positive behaviour management, supporting peer interaction, supporting mutual respect and understanding, and providing feedback on peer interactions 6 of 20 observed measures of child behaviour also indicated a significant programme effect: compliments others, mutual respect and understanding, involvement, taking turns in play, compliance with playground rules and including others (in play).

The Swiss trial (Malti et al., 2011, 2012) included 1675 first-grade students, with an average age of 7 years, from 56 schools. The trial compared PATHS to Triple P, a group parenting programme. Compared to the control group, children receiving PATHS displayed a significant reduction in aggressive behaviour (based on teacher and parent reports, but not child reports) and in ADHD symptoms (based on teacher reports only, not on parent or child reports). There were no effects on nonaggressive externalising behaviour or on social competence based on any measure. At the two-year follow-up, the effect on teacher-reported aggression and ADHD symptoms was statistically significant, but the effect on prosocial behaviour was not.

The Swedish trial (Eninger et al., 2021), comprised a sample of 285 children, aged 4-5 years from 26 schools. Children were randomly assigned to an intervention group (145 children) or a control group (140 children). The intervention resulted in significant improvements after 6 months in working memory, prosocial play and hyperactive behaviours in the intervention group compared to the control group.

One quasi-experimental study in the UK (Curtis & Norgate, 207) included 287 students, aged 5 to 7 years, from 5 intervention and 3 comparison schools. There were significant intervention effects on all 5 subscales of the SDQ. There was a significant improvement on emotional symptoms, conduct problems, hyperactivity, peer problems, and consideration, for intervention schools but not for the comparison schools. It is important to note that the levels of behavioural and emotional problems were already at a lower level in the comparison schools at pre-test.

The Dutch study (Goossens et al. 2012) included 1333 children aged 5 to 11 years from 18 kindergarten and elementary schools, half of which delivered the intervention and the other half served as control. There was a significant effect on only 1 of 27 outcome measures – emotional awareness - immediately after the intervention.

A quasi-experimental (Hughes & Cline, 2014) evaluated of the Preschool version was conducted in the UK with 57 children, aged 3 to 4 years, from 3 different preschools. One school delivered the full version, while one school delivered an adapted (shortened) version and the third school did not deliver PATHS. There was a significant interaction effect: the full PATHS group significantly improved their receptive emotion vocabulary from pre to post test, while the other groups did not. There was no effect on affective perspective taking skills, or parental measure of behaviour (SDQ). There were significant interaction effects on 6/7 scales of the teacher-reported SDQ: children in the full PATHS version improved significantly while the other two groups did not.

The Turkish study (Seyhan et al., 2017) also evaluated the Preschool version and included 565 children aged 4 to 6 years from 41 classrooms in 4 preschools. There were significant intervention effects on teacher-reported children’s social and emotional skills reflecting interpersonal relationships and emotion regulation, and observed quality of classroom environment. The effect on observed behaviours and management techniques of teachers was not significant. In terms of student-teacher relationship, as reported by teachers, there was no effect on conflict or closeness, but there was a significant effect on dependency. Teachers in intervention group reported significantly more dependency in their relationships with children. Children in the intervention group described their relationships as significantly more positively than did children in the comparison group.

The programme has been evaluated in five quasi-experimental studies, two studies in the Netherlands and one across the Netherlands and Belgium evaluated the programme with delinquent adolescents, while one study from Netherlands and one from Spain evaluated the programme implemented as universal prevention in schools.

In two Dutch studies, delinquent male adolescents aged 12 to 21 years recruited from three/four similar high-security juvenile correctional facilities participated, intervention group participants came from one facility while the control group from the remaining. In one study, 7/20 outcomes (measuring moral development, social information processing and social skills) showed a significant positive intervention effect. In the other study, there a significant positive intervention effect on cognitive distortions. The study also measured recidivism: the more participants from intervention group reoffended (53% v 29% at 12 months, and 86% v 65% at 24 months), but the difference was not significant.

234 incarcerated youth from high-security juvenile correctional facilities participated in the study, conducted across the Netherlands and Belgium. Intervention and control group participants came from different facilities. The majority (69%) were males, and the mean age was approximately 15.5 years. Significant differences were found between the experimental and control groups in the development of social skills and moral value evaluation both of which had a small to moderate effect size as the intervention group remained stable while the control group’s scores decreased. No significant differences were found between the experimental and control groups in the development of cognitive distortions and moral judgment.

Another Dutch study takes a universal preventive approach and was implemented in schools with students with a mean age of 14 years. 9 schools were assigned to groups according to their ability to implement the programme. There was a significant positive effect on self-serving cognitive distortions and attitudes towards antisocial behaviour in the experimental group compared to the control group, but the effect on prevalence of antisocial behaviour and moral judgement was not significantly different between groups.

The Spanish study was also conducted in schools with 89 participants aged approximately 14-16 years, and evaluated an adaption called EQUIPAR, the Spanish version of EQUIP for Educators. The study had mixed effects on thinking errors and no significant effects on victimisation.

The programme has been evaluated in four randomised controlled trials, one each in Norway, Sweden, the UK and the Netherlands.

In Sweden, 156 young people aged 12-17 with a clinical diagnosis of conduct disorder using the DSM-IV-TR were randomly allocated to either receive MST or to continue with treatment as usual. No significant differences between groups was found at post-test or month follow-up  – indicating no effects on child behaviour, social skills, delinquency, alcohol or drug use.

In Norway, 105 young people aged 12-17 years referred for problem behaviour such as law-breaking or other anti-social acts, serious academic difficulties, dysfunctional interpersonal relationships, verbal aggression and threats of hurting others were randomly allocated to MST or regular services. At posttest, there a marginally significant positive intervention effect on internalising and externalisaling behaviour, social competence and family cohesion, but not of family functioning.

In the Netherlands, 256 young people aged 12-18 years displaying severe and violent antisocial behaviour were randomly allocated to MST or usual service. At post-test and six-month post intervention, intervention group adolescents improved significantly more compared to the control group on parent and self-reported externalizing, parent-reported oppositional defiant and conduct disorder, and self-reported property offences. The There were no significant differences in groups in frequency or number of arrests two years after the program ended.   effect on self-reported violence was not significant.

In the UK, 108 young people aged 13-17 years on a court referral order for treatment, supervision, or following imprisonment were randomized into MST or Youth Offending Teams control group. The number of offenses between the two study groups did not differ at post-test, and 6-month follow-up but became significant (p<.001) at the 12-month follow-up assessment. There was a significant difference between groups, favouring MST, on the measure of six-month period of no offences, although the effects at different assessments points is not disentangled. Sub-group analyses showed this was significant for non-violent offences, and not for violent offences. Out of 21 tests for secondary outcome measures, 5 (24%) were significant, including aggression and delinquency.

I a quasi-experimental study in the Netherlands (Eeren et al., 2018), 697 adolescents with an average age of 15 years, were allocated to either the FFT intervention or the MST intervention according to the Risk-Need-Responsivity model. The FFT intervention is thereby seen as the control group. In this aspect, results of the comparison showed no significant differences between outcomes. Only the engagement in school or work after the treatment was higher in the group who completed MST.

The programme has been evaluated in three cluster randomised controlled trials (RCTs) – two in Germany and one in the Netherlands – and three quasi-experimental studies – one in each of Finland, Germany and Switzerland.

The two German RCTs with young people aged approximately 11-15 years. One study followed participants for up to one year after the competition ended, and the second study assessed participants 18 months after the competition ended. They found no effect on self-reported smoking.

The Dutch RCT, which involved 10-14 year olds, found a statistically significant effect favouring the intervention on the number of self-reported smokers at post-test but not 12-months after the competition ended. There was no effect on self-efficacy or attitudes towards smoking.

The Finnish study, with 14 year olds, found a statistically significant effect favouring the intervention for self-reported onset of smoking (defined as smoking daily) at post-test but not one year later.

The German quasi-experimental study, involving children aged 11-14 years, found statistically significant effects favouring the intervention on self-reported prevalence of smoking at post-test and self-reported daily smoking at post-test and six months later.

The Swiss study involved children aged approximately 13 years and did not find any effect on smoking at post-test.