Secondhand cannabis and tobacco exposure linked to lower cognitive scores in youth

Among 5,580 youth in the ABCD Study, secondhand and environmental exposure to cannabis and tobacco smoke was associated with worse cognitive performance, even without direct use.

Wade, Natasha E et al.·Biological psychiatry global open science·2023·Moderate EvidenceCross-Sectional
RTHC-05007Cross SectionalModerate Evidence2023RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Cross-Sectional
Evidence
Moderate Evidence
Sample
N=5,580

What This Study Found

Secondhand cannabis and tobacco exposure in youth were independently associated with lower cognitive performance across multiple domains, suggesting passive exposure may carry cognitive risks during brain development.

Key Numbers

N=5,580 youth from ABCD Study. Both secondhand cannabis and tobacco exposure associated with lower cognitive performance scores.

How They Did This

Cross-sectional analysis of ABCD Study year-2 follow-up data (N=5,580, 48% female). Assessed cognitive performance in relation to secondhand or environmental exposure to cannabis and tobacco smoke.

Why This Research Matters

As cannabis legalization increases, more children may be exposed to secondhand cannabis smoke. If passive exposure affects cognition during critical brain development periods, it has major implications for household cannabis policies.

The Bigger Picture

Decades of research established the harms of secondhand tobacco smoke. The equivalent research for cannabis is just beginning. These early findings from the largest US youth brain study suggest similar concerns may apply to cannabis.

What This Study Doesn't Tell Us

Cross-sectional design cannot establish causation. Exposure was likely measured via self/parent report. Children exposed to secondhand smoke may differ from unexposed children in many ways (family socioeconomic status, other environmental exposures). Cannot distinguish direct effects of smoke exposure from correlated household factors.

Questions This Raises

  • ?What level of secondhand cannabis exposure produces measurable cognitive effects?
  • ?Would longitudinal ABCD data show progressive cognitive impact with continued exposure?

Trust & Context

Key Stat:
5,580 youth; secondhand cannabis exposure linked to lower cognitive performance
Evidence Grade:
Large well-established cohort study. Cross-sectional design and potential confounding limit causal inference.
Study Age:
Published 2023.
Original Title:
Clouding Up Cognition? Secondhand Cannabis and Tobacco Exposure Related to Cognitive Functioning in Youth.
Published In:
Biological psychiatry global open science, 3(2), 233-242 (2023)
Database ID:
RTHC-05007

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

A snapshot of a population at one point in time.

What do these levels mean? →

Frequently Asked Questions

Can secondhand cannabis smoke affect children's brains?

This study found an association between secondhand cannabis exposure and lower cognitive scores in nearly 6,000 youth. While it cannot prove the smoke caused the cognitive differences, it raises concerns that parallel established findings about secondhand tobacco smoke and child development.

How are children exposed to secondhand cannabis smoke?

Children can be exposed when adults use cannabis in shared living spaces, vehicles, or outdoor areas near children. With increasing legalization and the finding that many households lack cannabis-free air rules, children's exposure may be growing.

Read More on RethinkTHC

Cite This Study

RTHC-05007·https://rethinkthc.com/research/RTHC-05007

APA

Wade, Natasha E; McCabe, Connor J; Wallace, Alexander L; Gonzalez, Marybel R; Hoh, Eunha; Infante, M Alejandra; Mejia, Margie Hernandez; Haist, Frank. (2023). Clouding Up Cognition? Secondhand Cannabis and Tobacco Exposure Related to Cognitive Functioning in Youth.. Biological psychiatry global open science, 3(2), 233-242. https://doi.org/10.1016/j.bpsgos.2022.01.010

MLA

Wade, Natasha E, et al. "Clouding Up Cognition? Secondhand Cannabis and Tobacco Exposure Related to Cognitive Functioning in Youth.." Biological psychiatry global open science, 2023. https://doi.org/10.1016/j.bpsgos.2022.01.010

RethinkTHC

RethinkTHC Research Database. "Clouding Up Cognition? Secondhand Cannabis and Tobacco Expos..." RTHC-05007. Retrieved from https://rethinkthc.com/research/wade-2023-clouding-up-cognition-secondhand

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.