Self-Guided Online Program Helps Cannabis Users Meet Their Reduction Goals in Two Weeks

A two-week online self-guided intervention using mental contrasting with implementation intentions helped 69% of participants meet their cannabis reduction goals, compared to 49% in the control group, with reductions maintained at three months.

Kroon, E et al.·Drug and alcohol dependence·2025·Moderate EvidenceRandomized Controlled Trial
RTHC-06864Randomized Controlled TrialModerate Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Randomized Controlled Trial
Evidence
Moderate Evidence
Sample
N=168

What This Study Found

The MCII group achieved objective reduction goals at 69%, vs. 49% for control (SMART goals alone). Adding cue-control did not improve outcomes (60%). All groups reduced grams per week, maintained at 3-month follow-up. Two-week retention was high in the MCII group.

Key Numbers

168 participants; 69% MCII group met goals vs. 49% control; 60% MCII + cue-control; reductions maintained at 3 months.

How They Did This

Pilot RCT with 168 adults using cannabis weekly (severe CUD on average). Three conditions: SMART goals only, SMART + MCII, SMART + MCII + cue-control. Two-week primary endpoint with 3-month follow-up.

Why This Research Matters

Many cannabis users prefer self-help over formal treatment. This brief, accessible online program can meaningfully help people meet their own reduction goals.

The Bigger Picture

Self-guided digital interventions could fill a major gap in cannabis treatment, reaching the large population of users who would never enter a clinic.

What This Study Doesn't Tell Us

Pilot/feasibility scale. No blinding. All groups reduced use. Grams per week reduction was similar across groups despite goal achievement differences.

Questions This Raises

  • ?Why did cue-control not add benefit?
  • ?Would a larger trial confirm these results?

Trust & Context

Key Stat:
69% of the MCII group met their cannabis reduction goals
Evidence Grade:
Randomized design with meaningful effect sizes, but pilot scale and lack of blinding limit evidence strength.
Study Age:
2025 pilot feasibility RCT with 3-month follow-up.
Original Title:
Back on track: Feasibility and efficacy randomized trial of a two-week online self-guided intervention for cannabis use reduction.
Published In:
Drug and alcohol dependence, 277, 112943 (2025)
Database ID:
RTHC-06864

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled TrialGold standard for testing treatments
This study
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Participants are randomly assigned to treatment or placebo groups to test cause and effect.

What do these levels mean? →

Frequently Asked Questions

Can you reduce cannabis use without formal treatment?

This study suggests a brief self-guided online program can help many weekly cannabis users meet their own reduction targets.

What is MCII?

Mental contrasting with implementation intentions: you imagine your goal, contrast it with obstacles, and create if-then plans. It outperformed goal-setting alone.

Read More on RethinkTHC

Cite This Study

RTHC-06864·https://rethinkthc.com/research/RTHC-06864

APA

Kroon, E; Elsey, J W B; Kuhns, L N; Rietveld, P; De Vries, O; Larsen, H; Wiers, R W H J; Cousijn, J. (2025). Back on track: Feasibility and efficacy randomized trial of a two-week online self-guided intervention for cannabis use reduction.. Drug and alcohol dependence, 277, 112943. https://doi.org/10.1016/j.drugalcdep.2025.112943

MLA

Kroon, E, et al. "Back on track: Feasibility and efficacy randomized trial of a two-week online self-guided intervention for cannabis use reduction.." Drug and alcohol dependence, 2025. https://doi.org/10.1016/j.drugalcdep.2025.112943

RethinkTHC

RethinkTHC Research Database. "Back on track: Feasibility and efficacy randomized trial of ..." RTHC-06864. Retrieved from https://rethinkthc.com/research/kroon-2025-back-on-track-feasibility

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.