Assessing the efficacy of MOTI-4 for reducing the use of cannabis among youth in the Netherlands: A randomized controlled trial (2016)

ENGLISH:
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 6 months (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.
Highlights:
Moti-4 is a tailored, individual brief intervention for youth problematic cannabis use.
Moti-4 had a significant positive influence on cannabis use (almost 50% reduction).
This effect was still present at the 6 month follow-up.
Moti-4 is an effective preventive intervention to address adolescent cannabis use.
FRANÇAIS :
Un essai randomisé contrôlé met en évidence l'efficacité à 6 mois d'une intervention de type motivationnel sur l'usage problématique de cannabis. L'étude a été réalisée aux Pays-Bas auprès d'un échantillon de 71 participants entre 14 et 24 ans, ayant rapporté une consommation de cannabis le mois précédant l'inclusion et 60 individus contrôle. L'étude met en évidence une association entre l'intervention basée sur l'entretien motivationnel, un renforcement du contrôle comportemental et l'auto-évaluation, et une réduction des consommations avec également des dépenses significativement moins importantes en termes d'achat de cannabis comparées à la population contrôle, à 6 mois (p < 0,05) et de consommation. Par ailleurs, être de sexe féminin, avoir deux parents natifs des Pays-Bas et présenter un plus grand contrôle comportemental perçu constituaient des facteurs protecteurs associés aux changements les plus significatifs en termes de modifications des dépenses et de nombre de joints consommés. [Actualités des addictions, 03/06/2016]