ICAN: an online training to reduce cannabis use.

Rationale:
It is estimated that almost 1% of European adults uses cannabis daily or almost daily. Regular cannabis use is associated with various adverse (mental) health effects. Regular cannabis users are at risk for dependence. There are effective treatments available for cannabis users. However, the majority of cannabis users does not seek help. Internet-delivered interventions have several advantages over traditional face-to-face treatments.Online interventions are characterized by a high degree of anonymity, this minimizes the fear of being stigmatized. Besides, they are easily accessible. Several online interventions for cannabis users have been developed. In a recently published meta-analysis on computerized interventions to reduce cannabis use, results showed a small but significant effect in favor of computerized interventions compared to control conditions. Thus, online interventions for cannabis use are effective and have several advantages over face-to-face treatments. Therefore, they may have the potential to improve treatment utilization among regular cannabis users. It remains unclear whether online interventions are able to motivate cannabis users to utilize specialized treatment services. Increasing drug treatment utilization also does not appear to be an explicit goal of the existing cannabis interventions. Given the low numbers of cannabis users entering treatment, it seems important to focus on increasing motivation to enter treatment. Interventions that aim to increase drug treatment utilization are often based on the principles of the Screening Brief Intervention and Referral to Treatment (SBIRT) approach. This research project aims to evaluate the effectiveness of an online self-help
training with adherence focused guidance for cannabis users to motivate and support them to stop or reduce their cannabis use and to refer them to treatment. The online training, a progressive web app, is based on the principles of the Screening Brief Intervention and Referral to Treatment (SBIRT) approach.

Objective: To test if an internet-based self-help training (screening, personalized feedback, brief intervention and referral to treatment) for reducing cannabis use shows favorable effectiveness (effect size d =.40) compared to the control condition (screening, feedback, online information brochure) on cannabis use 6 months post-randomisation.

Study design: A double blind randomised controlled trial will be carried out with a duration of 6 months in an online setting. The trial will be 2 armed (active internet-based self-help training x passive online information brochure).

Study population: Dutch non-treatment seeking frequent cannabis users, 18+ years old (meeting in/exclusion criteria).

Intervention: The online training, a progressive web app, is based on the principles of the Screening Brief Intervention and Referral to Treatment (SBIRT) approach. The brief intervention component is based on cognitive behavioral therapy and motivational interviewing techniques.

Main study parameters/endpoints: The primary outcome variable is the number of smoking days in the past 7 days, assessed 6 months post-randomisation using the Timeline Followback method.

We hypothesize that the online training will be more effective in reducing cannabis use and improving attitudes towards seeking help than the control condition (passive online information brochure).

Measurement waves will take place at baseline and 6 weeks, 3 months and 6 months post-randomisation.

The online training, a progressive web app, is based on the principles of the Screening Brief Intervention and Referral to Treatment (SBIRT) approach. The brief intervention component is based on cognitive behavioral therapy and motivational interviewing techniques.