While cannabis use prevalence is 9.9% in the EU among all adults, the prevalence among European young adults (15-24 years) is notably higher (18.6%). At the same time, young adults are the least likely to seek professional help for it. Traditional treatment brings with it barriers like: lack of awareness, time, cost, and stigma. What if youth could get help directly on their smartphones?
Peer Network Counselling – text (PNC-txt) is a 4-week long automated text-message intervention to help reduce cannabis use among youth with cannabis use disorder (CUD). It is based on principles of motivational interviewing (MI), a counselling approach that guides clients to channel their own intrinsic motivation and use it for positive change.
Over 4 weeks, participants received around 160 personalised messages i.e. approximately every other day, touching on topics like their own cannabis use patterns, the behaviour of their close friends, and the places in their daily life where cannabis use typically occurs. The content of these messages is based on information collected from participants at the start of the study such as cannabis use, peer relations, and plans for change. Moreover, the text messages are interactive and are updated based on participant feedback over the four weeks.
CORE
- Both the PNC-txt and the waitlist control group showed reductions in cannabis use that were not significantly different from one another.
- PNC-txt was helpful in increasing readiness to change cannabis use behaviours.
- PNC-txt also promoted the use of behavioural strategies to reduce the negative consequences of cannabis use.
- Increased readiness to change and use of behavioural strategies were linked to lower cannabis use up to 6 months later among those who used PNC-txt.
- Readiness to change cannabis use and the use of cannabis harm reduction strategies are strong candidates for the treatment of youth with CUD.
RESEARCH METHODS
WHAT? The aim of the study was to test whether PNC-txt would help young adults reduce using cannabis. Moreover, the researchers were interested in HOW PNC-txt works, namely the mechanisms of change. Therefore, they also studied processes targeted in PNC-txt such as peer network health, readiness to change, and the use of protective behavioural strategies.
WHO? 1078 young adults (18-25 years) with CUD from Tennessee and Colorado in the USA. They used cannabis on an average of 26 out of the past 30 days at the start of the study, indicating this was a group with very frequent, heavy use.
HOW? In this randomised controlled trial, participants either received PNC-txt or were assigned to a waitlist group that also served as the control group. They were followed from the start of the study with measurements at the end of the 4-week intervention period and after 6 months.
FINDINGS
- Broadly, the PNC-txt group did not have significantly reduced cannabis use compared to the control group.
- However, participants who used PNC-txt showed greater increases in their motivation to reduce cannabis use and their use of harm-reduction strategies after just 1 month, compared to the control group.
- These increases in motivation and harm-reduction strategies in turn predicted lower cannabis use at the 6-month follow-up in the PNC-txt group.
- The program worked equally well for participants living in rural and urban areas, suggesting good reach across geographic settings.
- Larger effect sizes were observed among those with the most frequent cannabis use at the start, suggesting the program may be especially valuable for the heaviest users.
DETAILS
Mason, M. J., Coatsworth, J. D., Riggs, N. R., Russell, M., Mennis, J., Zaharakis, N., & Brown, A. (2025). Text message-delivered cannabis use disorder treatment with young adults: A large randomized clinical trial. Journal of Substance Use & Addiction Treatment, 170. https://doi.org/10.1016/j.josat.2024.209611
This sci-fly was written by Suhaavi Kochhar (Radboud University) for RAD-blog, the blog about smoking, alcohol, drugs and diet.