Treating Alcohol Addiction Also Reduces Cannabis and Cigarette Use — Even When That's Not the Goal

Participants in an alcohol use disorder trial spontaneously reduced cigarette and cannabis use without being prompted, and cannabis reduction in early treatment was inversely associated with alcohol consumption.

Belnap, Malia A et al.·Alcohol and alcoholism (Oxford·2026·Moderate Evidenceclinical-trial
RTHC-08115Clinical TrialModerate Evidence2026RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
clinical-trial
Evidence
Moderate Evidence
Sample
N=102

What This Study Found

Cigarette use declined significantly over 12 weeks (p=.002); cannabis decreased early (p=.006) then rebounded (p=.03); early cannabis reduction was negatively associated with drinks per drinking day, suggesting a compensatory relationship.

Key Numbers

102 participants (61M/41F); significant cigarette reduction (p=.002); cannabis decrease early (p=.006) then increase (p=.03); cannabis changes inversely associated with drinks/drinking day (p<.05).

How They Did This

Secondary analysis of a 12-week RCT of ibudilast for AUD (N=102), examining unprompted changes in cigarette and cannabis use and their associations with drinking outcomes.

Why This Research Matters

The finding that treating one substance problem can ripple across others challenges the single-substance treatment model — and suggests comprehensive substance use screening should be standard in addiction trials.

The Bigger Picture

The early cannabis reduction followed by rebound could represent a substitution pattern — patients may initially reduce all substances but then return to cannabis as a coping alternative to alcohol.

What This Study Doesn't Tell Us

Secondary analysis not powered for these outcomes; relatively small sample; co-occurring use patterns make it difficult to isolate individual substance effects; ibudilast effects on other substances unknown.

Questions This Raises

  • ?Is the cannabis rebound a substitution effect?
  • ?Would targeting all three substances simultaneously improve outcomes?
  • ?Should AUD trials routinely track cannabis and tobacco use?

Trust & Context

Key Stat:
Evidence Grade:
Secondary analysis of a well-designed RCT with appropriate statistical methods, but limited by small sample and post-hoc nature.
Study Age:
Published in 2026, contributing to the growing evidence for comprehensive substance use assessment in addiction treatment.
Original Title:
Reductions in cigarette and cannabis use during a randomized clinical trial for alcohol use disorder.
Published In:
Alcohol and alcoholism (Oxford, Oxfordshire), 61(2) (2026)
Database ID:
RTHC-08115

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

Does treating alcohol addiction affect other substance use?

Yes — participants in this alcohol treatment trial spontaneously reduced cigarette and cannabis use without being asked to, suggesting treatment effects can extend beyond the targeted substance.

Is cannabis use related to alcohol consumption?

This study found an interesting pattern: early cannabis reduction was associated with lower alcohol consumption, but cannabis use rebounded later in treatment — possibly as a substitute coping mechanism.

Read More on RethinkTHC

Cite This Study

RTHC-08115·https://rethinkthc.com/research/RTHC-08115

APA

Belnap, Malia A; McManus, Kaitlin R; Kirsch, Dylan E; Grodin, Erica N; Ray, Lara A. (2026). Reductions in cigarette and cannabis use during a randomized clinical trial for alcohol use disorder.. Alcohol and alcoholism (Oxford, Oxfordshire), 61(2). https://doi.org/10.1093/alcalc/agag006

MLA

Belnap, Malia A, et al. "Reductions in cigarette and cannabis use during a randomized clinical trial for alcohol use disorder.." Alcohol and alcoholism (Oxford, 2026. https://doi.org/10.1093/alcalc/agag006

RethinkTHC

RethinkTHC Research Database. "Reductions in cigarette and cannabis use during a randomized..." RTHC-08115. Retrieved from https://rethinkthc.com/research/belnap-2026-reductions-in-cigarette-and

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.