What topics does this cannabis study cover?

This study covers research on: THC, Addiction, Mental Health.

Where was this research published?

Published in Preventive medicine on September 25, 2026.

Review finds substance policies can trigger mixed cross-use effects

Q: What did this research study find?

The review included **95 studies** and **250 evaluations** of how tobacco, cannabis, and alcohol policies relate to use of other substances.

From population outcomes to demand curves: A systematic review of cross-substance effects of tobacco, cannabis, and alcohol policies.

Preventive medicine • September 25, 2026 • Highly Relevant

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AI Summary

This systematic review asked whether policies targeting tobacco, cannabis, or alcohol also change use of the other substances. The authors searched four research databases through February 4, 2026, and included 95 studies contributing 250 evaluations of cross-substance relationships. Most evaluations came from real-world policy research, while a small number used behavioral economics experiments; the abstract does not describe a single enrolled human sample or one common intervention and comparison.

Across the evaluations, independence—no clear cross-substance response—was most common (105 evaluations), followed by complementarity, in which substances changed in the same direction (71), and substitution, in which they changed in opposite directions (39). Four evaluations reported mixed relationships, and 31 reported no effect on the substance directly targeted by the policy. Patterns differed by policy type, substance combination, and population, with subgroup analyses often revealing effects that were not visible in overall estimates. The review concludes that policy assessments should routinely measure outcomes beyond the intended substance. As an abstract-based summary, this review cannot establish one universal cross-substance effect or determine the size or clinical importance of individual policy impacts; the abstract also notes that experimental evidence remains limited.

💡 Key Findings

The review included 95 studies and 250 evaluations of how tobacco, cannabis, and alcohol policies relate to use of other substances.

High

90%

Independence was the most common cross-substance pattern (105 evaluations), followed by complementarity (71) and substitution (39).

High

90%

Cross-substance effects varied by policy type, substance combination, and population, and subgroup patterns were often not apparent in aggregate estimates.

High

85%

Behavioral economic findings were broadly consistent with real-world policy evaluations, but experimental evidence remains limited.

High

85%

The review concludes that policy evaluations should routinely assess outcomes beyond the substance directly targeted.

High

90%

📄 Original Abstract

OBJECTIVE: Tobacco, cannabis, and alcohol use frequently overlap, so policies targeting one substance may also affect use of others. This review aimed to synthesize evidence from policy evaluation and behavioral economics on the own- and cross-substance effects of tobacco, cannabis, and alcohol policies. METHODS: We searched PubMed (1946), PsycINFO (1600), CINAHL Complete (1937), and Web of Science (1900) through February 4, 2026, for studies evaluating price-related and regulatory policies targeting tobacco, cannabis, or alcohol. RESULTS: Ninety-five studies contributed 250 evaluations of cross-substance relationships, including 245 real-world policy evaluations and five behavioral economic evaluations. Across evaluations, independence was most common (n = 105), followed by complementarity (n = 71) and substitution (n = 39); four evaluations reported mixed relationships, and 31 reported no own-substance effect. The direction and consistency of effects varied across policy domains and substance combinations, and heterogeneity analyses frequently identified subgroup-specific patterns not apparent in aggregate estimates. CONCLUSIONS: Substance use policies can have effects beyond their intended targets, with cross-substance responses varying by policy type, substance combination, and population. Behavioral economic findings were broadly consistent with real-world policy evaluations, although experimental evidence remains limited. Comprehensive policy evaluations should routinely assess cross-substance outcomes to better characterize the full public health impact of substance-related policies.

Paper Type

📄 Research

Publication

Journal: Preventive medicine
Published: September 25, 2026
PMID: 42790649
DOI: 10.1016/j.ypmed.2026.108665

Authors (8)

Roberta Freitas-Lemos Medical University of South Carolina, Charleston, SC, USA. Electronic address: rflemos@vtc.vt.edu.
Ana Carolina de Lima Bovo Medical University of South Carolina, Charleston, SC, USA.
Laura E Bruckner Virginia Tech, Blacksburg, VA, USA.
Madeleine G Mason Francis Marion University, Florence, SC, USA.
Fábio Henrique Baia Universidade de Rio Verde (UniRV), Rio Verde, Goiás, Brazil.
+3 more authors