MONTREAL LONGITUDINAL EXPERIMENTAL STUDY

Principal Investigator: Richard E. Tremblay

Level of Intervention: Indicated

Target Population: Aggressive 7-9 year old children

References: Tremblay, Masse, Pagani, & Vitaro (1996); Tremblay, Vitaro, Bertrand, LeBlanc, Beauchesne, Boileau, & David (1992).

Theory (Risk & Protective Factors Targeted):
Based on the early starter model of antisocial behavior, aggressive behavior still present upon entrance to Kindergarten may reflect a failure to learn developmentally appropriate inhibition or use of prosocial strategies to achieve goals. Adults perceive these children as deviant and they are often rejected peers. It is hypothesized that given that gender and SES are both strong correlates of physical aggression and interact, it is likely that long-term risk is increased for low-income boys.

Based on research showing that both factors affect the development of disruptive behaviors, the intervention simultaneously targets parent behavior and child social skills.

Description of Intervention:
Based on model developed at Oregon Social Learning Center (Patterson, 1982; Patterson, Reid, Jones, & Conger, 1975). Parent training is targeted at improving parental behavior (e.g. improve monitoring & positive reinforcement, teach effective, non-punitive discipline, improve coping with crisis) and child social skill training in order to reduce aggressive behavior in the children.

Parent Training Component
Each member of a multidisciplinary team was assigned to work with 12 families. Sessions were scheduled every 2-3 weeks over 2 year period. Families received different amounts of intervention (average 20 sessions) based on need; no family received more than 46 sessions (mean = 17.4 sessions). Consultants helped parents generalize the skills they were learning. There was some contact between the professional consultants and the children’s teachers.

Social Skills Training Component
A member of the multidisciplinary team that was not working with the family implemented the program in the schools at lunchtime. Target children were placed in groups with 3-5 teacher-identified prosocial peers. Sessions used coaching, peer modeling, and role playing techniques. Reinforcement contingencies were also implemented to encourage use of positive behavior. During the first year of the program, 9 sessions focused on developing prosocial skills (e.g. group entry, help seeking). The second year consisted of 10 sessions focused on developing self-control skills (e.g. following rules, managing anger-inducing situations).

As part of another program, one subset of the sample (n=25) received additional training in the use of fantasy and another subset (n=9) received a program designed to be critical of television.

Research Subjects:
The subjects were 166 Caucasian, Canadian-born males, primarily low-income, with French-speaking parents. Boys with disruptive behavior scores > 70th percentile (N=259) on the Social Behavior Questionnaire (SBQ; Tremblay et al., 1991) that also met other selection criteria (i.e. ethnicity and education) were eligible for participation (n=249). Children whose parents had more than 15 years of school were excluded from participation. Mean age of subjects was 6.1 years.

Research Design:
Teachers in 53 Montreal schools with lowest SES index assessed all male students in their classes (1,161 boys). Eligible subjects were randomly assigned to treatment group (N=43), control group (N=41), or an attention-placebo control group (N=82). Normative data were provided from a sample (n = 1,000) drawn from the same population as the treatment subjects. Intervention was administered from September 1985 to June 1987.

Outcomes:
Measures included parent ratings of disruptive, anxious, inattentive, and prosocial behavior were drawn from the SBQ. School records provided data regarding class placements. The Pupil Evaluation Inventory (PEI; Pekarik, Prinz, Liebert, Weintraub, & Neale, 1976) was used to assess disruptive behavioral, withdrawal and likability according to peers. Children were asked to provide information regarding delinquency, gang membership, sexual activity, and academic motivation.

At pre-test, mean levels for treatment groups were typically midway between the attention placebo-control and control groups on teacher ratings of behavior but these differences were not statistically significant. Overall, no differences in terms of who consented for treatment but higher levels of consents in families of boys who were frequent fighters (p<.01). The groups of disruptive boys (treatment, control, attention-placebo control) did not differ significantly on demographic variables except that in the treatment group, mother’s last occupation was of a significantly lower level than that of control group mothers. The sample of disruptive boys and the normative comparison group differed significantly in a number of ways. Families with disruptive sons were more disadvantaged (p<.001) and both parents tended to have lower levels of education (p<.001). The total family income for these families was lower than that of the comparison families (p<.001) and the parents were younger when their son was born (p<.001) compared to the normative group.

There were limited significant differences between groups at post-test and follow-up. At age 12, the placebo-control group was rated as significantly more inattentive (p<.05).

Post-test (age 9 & 10)
Treatment boys were significantly more likely to be in age-appropriate regular grade compared to both control groups (p<.05) at age 10. There were no significant differences on teacher ratings of fighting post-treatment (age 9 or 10) or on School Adjustment Index at age nine.

There was a short-term "paradoxical" impact on mother’s perceptions of child antisocial behavior. Post-treatment, mothers of treatment boys reported that their sons were more disruptive (p<.02), more inattentive (p<.05), & fought more (p<.003) than mothers of non-treated boys. These differences were no longer present at age 10,11, or 12. The authors presented data that suggested this finding was due to increased monitoring and accuracy of maternal reports.

Follow-up (age 11 & 12)
At age 12, treatment boys were rated by teachers as significantly less likely to be engaged in fighting compared to controls (p<.03). Treatment boys were significantly less likely to be classified as having serious difficulties compared to controls (22% vs. 44%) and were more likely to be rated as being well-adjusted (29% vs. 19%) or having only some difficulties (p<.05) based on the School Adjustment Index (composite of teacher & peer ratings of disruptive behavior and class placement).

The authors used discriminant function analysis to examine how treatment, as a factor along with early behavior problems and family adversity, predicted the presence or absence of serious difficulties at age 11-12. Results indicated that treatment explains part of adjustment outcome after level of family adversity was taken into account and is a better predictor than pre-treatment level of behavior problems. The discriminant function correctly classified 69% of the subjects (69% true positives & 69% true negatives).

Using self-report data across ages 10-12, results indicated that treatment boys engaged in significantly less delinquent activity compared to controls (p<.003 to p<.05).

Early Adolescent Outcomes
Across early adolescence (age 11 to 15), treated boys less likely to report gang membership (p<.01), drinking to the point of being drunk (p<.02) or taking drugs (p<.05). Group differences on teacher-reported disruptiveness did not remain significant when levels were compared from age 10 to age 15.

Strengths & Limitations:
The Montreal Longitudinal Experimental Study is a preventive intervention for children at risk for developing antisocial behavior due to early behavior problems. It is a multi-component program that targets risk factors within the child and the family. The evaluation of the program has been ongoing for the past decade and although the initial results were minimal, they have strengthened over time. There were no program effects until one year after the intervention and changes in problem behaviors were not evident until three years post-intervention and beyond. It is promising that an intervention conducted in elementary school has been shown to improve a variety of negative adolescent outcomes (e.g. gang involvement, substance use, delinquency). While the design was strong (i.e. randomized clinical trial) and the long-term outcomes are impressive, there are some issues that should be considered when interpreting these findings. First, it is important to recognize that this program was conducted on a sample that was entirely male and 100% Caucasian. The intervention dosage was also not consistent between participants. Families received different dosages at discretion of the consultants and six families in the treatment condition did not receive any of the parenting sessions. Multiple informants were used to measure outcomes, which is important, but no observational measures utilized. There has been no independent replication.

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