Stages of Change Model has Limited Value in Explaining the Change in Use of Cannabis among Adolescent Participants in an Efficacious Motivational Interviewing Intervention.

Previously, a Dutch randomized controlled trial evaluating an intervention aimed at changing adolescents' cannabis use, called Moti-4, has shown its efficacy. A secondary analysis of the Moti-4 data investigated the process of change specified by the Stage of Change (SOC) model in cannabis use during the trial. Seventy-one Moti-4 participants and 60 controls were recruited for the study with a pre-test, post-test (T1), and six-month follow-up (T2). All participants showed signs of problematic cannabis use. No contribution of the Moti-4 intervention to a change in SOC between T1 and T2 was found. Although motivation for treatment and motivation for change can be conceived as independent predictors of treatment outcome, the SOC a person is in does not mediate the effect of the intervention on change in cannabis use. However, a reduction in cannabis use was associated with a positive change in "action willingness," in line with the SOC model. In contrast to model expectations, a higher score on "contemplation" is associated with a higher cannabis consumption. Results highlight both the limitations and usefulness of the SOC model. Future interventions may focus more on the stage of "action willingness," as well as on perceived social norms.

Assessing the Efficacy of MOTI-4 for Reducing the Use of Cannabis Among Youth in the Netherlands: A Randomized Controlled Trial.

The Moti-4 intervention, in which motivational interviewing, self-monitoring, and strengthening behavioral control are used, was developed in the Netherlands in response to several rapid assessments of problematic use of cannabis among vulnerable adolescents. The main goal of the study reported in this article was to determine whether the Moti-4 intervention was able to reduce two outcome measures pertaining to the level of cannabis use; the amount of Euros spent a week on cannabis and the mean number of cannabis joints (cigarettes) smoked in a week. In a randomized controlled trial (RCT) with a 6-month follow-up, 27 trained Dutch prevention workers recruited 71 Moti-4 participants and 60 controls assigned to usual care. Participants were Dutch youth aged 14-24 years who had used cannabis during the preceding month. At baseline (T0), post-test (T1) and 6-month follow-up (T2), participants completed a questionnaire with 51 items. The 27 prevention workers also completed a checklist to assess the fidelity of delivering each item to each participant in the Moti-4 protocol. Multilevel and binary logistic regression was used to assess the impact of the prevention worker and 14 participant variables on the likelihood of drop-out. Mean scores for cannabis use outcome measures by Moti-4 participants and controls at baseline, T1 and T2 were compared using paired sample t-tests. Top-down multiple regression was used to assess relationships between Moti-4 and 13 other variables on the one hand and changes in weekly cannabis use at T1 and T2 on the other. The Moti-4 experimental condition had a significant and positive influence in reducing the level of expenditure on cannabis (p<0.05). There was no significant difference in outcome, neither for the 4 participating institutes nor for the professionals implementing the intervention. Baseline cannabis use was the strongest predictor (p<0.001) of weekly cannabis expenditure at posttest and 6-month follow-up. This effect was still present at T2. Being female, having two Dutch parents and perceived behavioral control also made significant positive contributions (p<0.05). Attitude at baseline was only related to cannabis expenditure after 6months (p=0.005). At T2 Moti-4 participants were found to have a significant reduction in the number of joints smoked weekly compared to T0 (on the average 4 joints). The study demonstrated that Moti-4 is an effective intervention to reduce cannabis use in youth.

Developing the Moti-4 intervention, assessing its feasibility and pilot testing its effectiveness.

BACKGROUND: The Moti-4 intervention was developed to prevent addiction and other health problems among vulnerable adolescent cannabis users. The aims of Moti-4 are to reduce the use of cannabis among adolescents and to encourage their motivation to change their behavior. METHODS: Intervention Mapping, a systematic approach to developing theory- and evidence-based interventions, was used to develop a protocol for the intervention. The process of developing the intervention also used the method of responsive evaluation to explore the opinions of the immediate target group and intermediaries (N = 31). Feasibility was assessed in 9 interviews and analyzed in grids. A quantitative pilot analysis involving a pre- and post-assessment in 31 subjects assessed whether the intervention was able to reduce drug use and would change intentions to change drug use behavior. RESULTS: Using Intervention Mapping resulted in the development of a substantial four-session intervention with a clear manual and training for prevention workers. The choice of 12 consecutive steps was based on the Trans Theoretical Model of Behavior Change, Motivational Interviewing, Theory of Planned Behavior and the Self Determination Theory. Positive aspects of working with Moti-4 were assessed in a feasibility study. Criticism by users has led to improvements to the manual. In the pilot study, the average weekly amount spent on cannabis decreased significantly from an average € 17.77 to € 11,95 in the period after the intervention, with a medium effect size (d = 0.36). Likewise, a significant decrease was found in the frequency of use during the past week, from 4.3 to 2.4 (d = .52). As to motivation to change, a statistically significant increase was found in planning (d = .44) and a large increase in the desire to stop (d = .76). The change in the motivation to smoke less cannabis was small. CONCLUSION: Intervention Mapping proved to be a useful approach for the development of the intervention, using a productive combination of theory and community knowledge. The pre- and post-test pilot study showed that the intervention generally brought about a considerable positive change in the two principle targets, cannabis use and motivation. There is a need for further (controlled) research into its effectiveness and implementation as a standard method in addiction prevention services.

The application of the rapid assessment and response methodology for cannabis prevention research among youth in the Netherlands.

BACKGROUND: Drug prevention methods tailored to specific target groups have become increasingly important. There is a growing need to find ways to rapidly assess and situate target groups in their particular contexts. This need is associated with the implementation of evidence-based interventions (EBIs) for these specific target groups. METHOD: This article describes the application of Rapid Assessment and Response (RAR) as a necessary first step in designing and implementing a prevention intervention plan for problematic cannabis use among "loitering" youth in the South of the Netherlands. Seven RAR studies were conducted using an innovative stepwise model in which the prevention field worker is central. RESULTS: The normative structure for the use of cannabis was found to vary across the neighborhoods of the RAR studies and emerged as the focal point in designing a suitable response. The RAR studies also identified the need in the prevention toolbox for a tailored, low-threshold, effective, individual brief intervention for youth problematic cannabis use. CONCLUSION: The RAR was found to provide a powerful methodology for detecting target groups and generating contextual and normative data that enable the prevention field worker to select and adapt from the spectrum of existing Evidence based Interventions (EBIs) or develop the most promising model for implementation with the specific target group.