Ineffective parenting is a well-established risk factor for the development of externalizing behavior problems in children [
]. The role of parenting in the emergence and maintenance of problematic child behavior is cogently explicated in Patterson’s Social Interaction Learning (SIL) model [
]. Briefly, the SIL model assumes that ineffective rearing practices have a direct detrimental influence on the behavior of the child, thereby hindering its healthy social-emotional development. More precisely, persistent coercive parenting—which is characterized by hostility and holding power over children via punitive or psychologically controlling means—can promote overt forms of externalizing behavior problems, such as noncompliance, temper tantrums, and verbal and physical aggression, which in turn are maintained by negative reinforcement of the parents [
]. Contextual factors, such as socio-economic disadvantage, parental psychopathology, and child temperament, are assumed to have a negative impact on parenting quality. For example, research has shown that parents of children with Attention Deficit Hyperactivity Disorder (ADHD) are less rewarding and consistent, display lower levels of warmth and involvement, and more often use physical discipline in comparison to parents of children without ADHD [
]. When children become more negative in their behavior, they are harder to discipline, which leads to parents using even more aversive strategies [
]. In this way, families become entangled in a downward spiral of negativity.
The antisocial behaviors acquired at home also tend to generalize to other social settings, such as school and sporting clubs [
]. Within the peer group, the antisocial behavior can lead to rejection by normal, prosocial peers. In turn, this can lead to associations with deviant peer groups [
] in which it pays off to show negative behaviors like lying, stealing, and vandalism [
]. However, parents also make a contribution to such deviant behavior by poor monitoring of the whereabouts and behaviors of their children outside the home environment. It enables youngsters to wander away from home and to engage in, for example, drug use and criminality [
]. These antisocial behaviors in childhood may take the form of an Oppositional Defiant Disorder (ODD) or Conduct Disorder [CD;
], which have been shown to be possible precursors of Antisocial Personality Disorder in adulthood [
The fact that externalizing behavior problems in children can have significant negative long-term consequences, underlines the importance of early intervention programs. Many of these programs focus on the improvement of parenting practices and there is indeed evidence showing that the enhancement of positive and more effective parenting is an important mechanism that promotes children’s prosocial behavior [
]. A good example of an intervention that is based on the key principles of the SIL model is parent management training—Oregon model (PMTO). The program is especially developed for the parents of children between 4 and 12 years of age showing the severe behavior problems associated with ODD or CD and aims to teach parents how to reduce coercive parenting practices and to replace these with five effective parenting practices: encouragement (i.e., stimulation of prosocial behaviors in the child by using scaffolding techniques and positive reinforcement), effective discipline (i.e., consistent use of mild sanctions like giving a time out), monitoring (i.e., knowing the child’s friends and keeping track of its activities), problem solving (i.e., responding effectively to rule-breaking behaviors and settling arguments with the child), and positive involvement [i.e., giving love and warm attention and engaging in fun activities with the child [
Initial studies conducted in the Unites States (US) have demonstrated that PMTO is an effective intervention for reducing externalizing child behavior problems [e.g.,
]. For instance, in the study by Forgatch and DeGarmo [
], 238 recently divorced mothers were randomly assigned to PMTO or a no intervention control condition. After 12 months, it was found that in the PMTO condition the effective parenting practices had significantly improved compared to the control condition. At a long term follow-up, 9 years after the PMTO intervention, there was still a significant difference between the boys in the PMTO condition and the control group with the former showing lower levels of delinquency, criminal activities, and convictions [
]. Furthermore, PMTO has also been shown to be effective in newly formed families consisting of biological mothers and stepfathers: again, parenting practices improved and behavior problems of the child decreased, as compared with newly formed families who did not receive an intervention [
]. Finally, in foster families, researchers found a success rate of permanent placements of 90 % for PMTO versus 64 % for Care As Usual (CAU) at an assessment which took place at 24 months after the interventions. PMTO was also significantly associated with reductions of stress for both the children and the foster parents [
The first randomized controlled trial (RCT) on the effectiveness of PMTO conducted outside of the US was completed in Norway, in which 112 clinically referred boys and girls aged between 4 and 12 years were randomly assigned to either PMTO or CAU [
]. Results indicated that PMTO was superior to CAU on the post-treatment outcome measures relating to effective discipline, obedience of the child, child-initiated negative behaviors and externalizing behavior problems. The effect of PMTO appeared to be moderated by the age of the child: that is, the intervention proved to be more effective in children below 8 years of age than among older children [
]. Further, at a 1-year follow-up, the differences between PMTO and CAU on child behavior problems and parental discipline were no longer significant [
]. A highly similar RCT was conducted in Iceland by Sigmarsdóttir et al. [
], who also allocated clinically referred children with behavior problems aged 5–12 years (
= 102) to either PMTO or CAU. PMTO was found to be more effective than CAU in improving general child adjustment post-treatment, although the only significant effect was documented for social skills. Surprisingly, this study did not obtain support for the idea that PMTO would have a positive effect on parenting skills [
Although PMTO is proven to be effective in the US, Norway and Iceland, this does not necessarily guarantee that this intervention also works in other countries. Therefore, the present study evaluated the effectiveness of PMTO in The Netherlands. One-hundred-and-forty-six families of clinically referred children with externalizing behavior problems aged between 4 and 11 years were included. The majority of the children (
n = 96) was randomly assigned to either PMTO or CAU (in two treatment centers, such randomization was not possible as they only offered one of these interventions). Effects of PMTO and CAU were examined by means of measures of child externalizing behavior, parenting skills, and parental stress and psychopathology, which were administered at baseline, and three follow-up measurements after 6, 12, and 18 months. Parents’ treatment satisfaction was also evaluated after 6, 12, and 18 months. In addition, effect size and clinically significant change in children’s externalizing behavior problems was examined and compared across both treatment conditions, and several possible moderators of the effects produced by PMTO were explored (i.e., child, parent, and family variables). The following hypotheses were tested: (1) PMTO will result in greater improvements of children’s behavior problems, parenting skills, and parental stress and psychopathology than CAU; (2) PMTO will be associated with higher treatment satisfaction of parents as compared to CAU; and (3) PMTO will show a greater proportion of clinically significant change than CAU. With regard to moderator effects, predictions were less obvious, although it can be hypothesized that PMTO is more effective in families displaying the characteristics that are the target of this intervention (i.e., poor parenting skills) or that facilitate the application of the newly acquired skills in daily life (e.g., higher educational level of parent).
The present study compared the effectiveness of PMTO and CAU in Dutch children who had been referred to child care organizations because of externalizing behavior problems. It was hypothesized that the PMTO treatment would result in a greater reduction of externalizing behavior problems in children, greater improvements in effective parenting skills, and less parenting stress and parental psychological complaints as compared to CAU. Furthermore, it was expected that parents in the PMTO condition would be more satisfied with the treatment than parents in the CAU condition. Finally, it was hypothesized that children who had received PMTO would more often show clinically significant change than children treated with CAU.
In contrast with our expectations, the results revealed no statistically significant differences in effectiveness between PMTO and CAU on the primary treatment outcome measures of parent-reported externalizing behaviors. That is, children in both conditions showed a significant decrease in CBCL externalizing and PDR scores within the first 6 months of treatment, after which symptom levels remained fairly stable. For parent-rated internalizing and total behavior problems, a similar pattern was found: in both treatment conditions significant decreases were found during the first 6 months, but no evidence was obtained that children in the PMTO condition fared better than those who received CAU. The fact that internalizing symptoms were also reduced following interventions which essentially target externalizing problems, suggests that either non-specific treatment factors were at work or that both interventions were capable of tackling a process underlying both types of problems. However, a reduction of internalizing behavior problems is a common finding in studies evaluating parent training programs for externalizing behavior problems [e.g.,
]. No effects were found for teacher-reported behavior problems. One explanation for this unexpected result might be that children’s behavior problems are less apparent at school and that, therefore, change was less noticeable. Indeed, the data indicated that teachers in general reported less problem behavior as compared to parents. Alternatively, it is also possible that the positive treatment effects did not generalize to the school setting and that the interventions are only effective in the context where they have been implemented (i.e., at home).
The finding that PMTO did not result in a greater decrease of externalizing behavior problems than CAU, is in contrast with the results of previous studies showing a superiority of PMTO over control interventions [e.g.,
]. However, it is important to note that most of the earlier studies that have been conducted in the United States compared PMTO to a waiting list control condition. The families included in the control condition of our study also received a proper treatment, which turned out to be rather effective in reducing children’s externalizing problems. Our findings seem to be more in line with the results of two PMTO effectiveness studies conducted in Norway and Iceland, which also included a control group that received an alternative treatment [
]. The Norwegian study demonstrated that PMTO initially resulted in a larger decrease in problem behaviors than CAU, but also found that this difference was no longer significant at one-year follow-up [
]. In the Icelandic study, PMTO produced a better treatment effect than CAU on children’s social skills, but not on behavior problems [
]. It is noteworthy that the effect size of CAU in our study was generally larger than that obtained in the other studies, which indicates that the general treatment offerings for children with externalizing problems in The Netherlands appears to be of good quality. This probably is a result of the fact that many psychologists in this country are trained to apply cognitive-behavioral techniques, which seem to be an important ingredient of effective interventions for children with externalizing problems [
]. In addition, PMTO is not the only treatment for externalizing behavior problems in The Netherlands that was not more effective than CAU [e.g., Triple P;
Contrary to our expectations, no significant differences between PMTO and CAU were found with regard to the application of effective parenting skills. Only three significant findings on parenting skills emerged. The first one was that parents in both conditions reported a significant increase in self-reported discouragement of undesirable behaviors over time. This suggests that parents in general became more responsive to the misbehaviors of their child. Second, parents reported an increase in their overall use of self-reported effective parenting practices over time. Third, when analyzing the behavioral observation data on parenting behavior, neither PMTO nor CAU showed significant improvement in parenting skills over time for the main caregiver. However, a difference between PMTO and CAU was found for interpersonal atmosphere of the second caregiver. The second caregiver who had received PMTO demonstrated a more positive interpersonal atmosphere over time as compared to the second caregiver who had received CAU.
PMTO, as derived from the SIL model, assumes that the reduction of problematic child behavior is mediated by improvements in parenting skills. In particular effective discipline is thought to be an important target mechanism involved in the elimination of child externalizing problems [
]. Note, however, that this could only be demonstrated with the self-report measure in our study, and this may be due to several reasons. First of all, the observational tasks we used did not elicit particularly high levels of negative behaviors in the child, so parents hardly had to discipline their child during these assessments. Even at baseline, when children were expected to show clear signs of externalizing behavior, the frequency of such problems was less than one out of the seven observation tasks. A second explanation concerns the (un)reliability of the observations. It should be noted that not all parenting scales had satisfactory inter-rater reliability (e.g., discipline). Further, one could argue that the SITs were too well-structured for the oppositional-defiant behavior of the child and the accompanying parenting responses to emerge, which of course questions the ecological validity of our observation measure. Still, it eludes us why our children ‘behaved so well’ during the tasks, because we used tasks very similar to the ones used in the original studies [e.g.,
]. One difference is that our SITs were typically administered in a plain room with few distractors, while in the original studies toys and other distractors were available and present in the room. Similar points of critique can be raised regarding the self-report measure of parenting skills. The internal consistency of five out of six subscales of the CWL was unsatisfactory, and there are data that seriously question the validity of this measure [
]. Nevertheless, the two reliable scales of the CWL (discouraging undesirable behavior and CWL total score) did show a positive treatment effect.
In both conditions, significant reductions of parenting stress and parental psychopathology within the first 6 months were found, with no significant differences observed between PMTO and CAU. These results indicate that parents generally felt better as a result of both types of treatment. Apparently, the improvements in their child’s behavior make parents feel less stressed during daily interactions with their child, which may well translate into an overall improved sense of well-being, although the direction of this effect may also be reversed: receiving treatment may boost parental self-efficacy and well-being, which in turn has a positive impact on children’s behavior [e.g.,
Although it was expected that parents in the PMTO condition would be more satisfied with the treatment compared to CAU, this was not confirmed by our results. Parents receiving PMTO were just as satisfied as parents receiving CAU. However, it may well be that treatment satisfaction is intimately related to treatment effectiveness. Since PMTO appeared to be equally effective as CAU, it was not surprising that parents were also comparably satisfied with both types of interventions.
Not all children profited equally from the PMTO and CAU interventions. A detailed analysis (combining reliable change and clinical cut-off) indicated that 17 % of the children within the PMTO group recovered and 46 % showed reliable improvement in externalizing behavior. In comparison, in the CAU condition 10 % of the children recovered and 43 % reliably improved. Yet, these differences between PMTO and CAU in reliable change were not significant, implying that PMTO did not yield more clinically significant change, which is in accordance with our results discussed above. To determine if some children benefited more from PMTO than others, several possible moderators were examined. Only one moderator effect was found: children who improved or recovered had significantly higher parent-rated externalizing behavior problems at baseline as compared to children who did not change or worsened. Thus, especially children with serious externalizing behavior problems appeared to benefit more from PMTO. This result is probably due to the fact that there was simply more room for improvement for these children. Possibly, more moderator effects would have been found when using only the recovered and deteriorated children in the comparison. However, in the present study, these subgroups were too small to conduct such analyses.
A number of limitations of the present study should be mentioned. First, although the study was originally designed as a RCT, due to practical constraints, we had to continue as a quasi-experimental investigation about halfway through the study. This also resulted in an unequal number of families in the PMTO and CAU conditions. Second, we did not have information about the actual number of treatment sessions that families in both conditions received, and therefore we were not able to control for treatment exposure. Also, information on medication use was not systematically documented. Third, as described above, the assessment of parenting practices appeared to be quite problematic, and this appeared true for both the self-report measure (CWL) and the observations (SITs). With regard to the observational index, an additional shortcoming was that coders not always remained blind to treatment condition and time-of-assessment (i.e., T0, T1, T2, T3), because of (unwanted) comments about the treatment made by parents or the assessor during the interaction tasks.
In spite of these limitations, we can conclude that a PMTO intervention produced positive effects in a clinically referred sample of children with externalizing problems in the Netherlands. More precisely, this treatment was effective in reducing children’s problem behaviors (even showing a quite large effect size), increasing the use of self-reported effective parenting practices, and reducing parenting stress and psychopathological symptoms of the parents, albeit no more effective than CAU. For both conditions, the improvements were most evident during the first 6 months of the study and remained stable until 18 months after baseline. Although many effects of the present study were in favor of PMTO and comparable to the effects of PMTO in other European countries, CAU in our study appeared to perform better than the control conditions in most other studies. It is remarkable to note that many of the CAU interventions performed within the Dutch youth care system also include the therapeutic ingredients, such as the use of ‘time out’ for disciplining and rewarding desired behaviors, that are considered important in PMTO. In a future study, the cost-effectiveness of PMTO will be compared to CAU. Annual youth service costs have been rising steadily over the past decade in The Netherlands, and a cost-benefit analysis will provide policy makers and insurance companies with quality information to guide decision-making, in the interest of young children, families and society at large.