Children exposed to cannabis during pregnancy had higher stress hormone levels at age 6

In a study of 2,577 mother-child pairs, prenatal cannabis exposure (combined with tobacco) was associated with higher cortisol levels in children at age 6, suggesting lasting effects on stress hormone regulation.

Cajachagua-Torres, Kim N et al.·Drug and alcohol dependence·2021·Moderate EvidenceProspective Cohort
RTHC-03039Prospective CohortModerate Evidence2021RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Prospective Cohort
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

Children exposed to cannabis during pregnancy (combined with tobacco) had significantly higher hair cortisol concentrations at age 6 (log-10 difference 0.16, 95% CI 0.04-0.28). This was not mediated by birth weight. Paternal cannabis use and maternal tobacco-only use were not associated with childhood cortisol changes.

Key Numbers

2,577 mother-child pairs; hair cortisol measured at age 6; significant cortisol increase with cannabis+tobacco exposure; no effect from tobacco alone or paternal use; not mediated by birth weight

How They Did This

Population-based prospective birth cohort of 2,577 mothers and children. Parental substance use collected by questionnaire with urine confirmation. Child hair cortisol and cortisone measured at age 6 as biomarkers of long-term HPA-axis functioning.

Why This Research Matters

Elevated cortisol in childhood is linked to increased stress reactivity and vulnerability to mental health conditions. If prenatal cannabis exposure permanently alters the stress hormone system, this could have lifelong health implications.

The Bigger Picture

This adds a specific biological mechanism to concerns about prenatal cannabis exposure, showing that the developing stress response system may be permanently altered, potentially increasing vulnerability to anxiety, depression, and stress-related conditions later in life.

What This Study Doesn't Tell Us

Cannabis exposure was combined with tobacco in most cases, making it difficult to isolate cannabis-specific effects. Self-reported substance use may underestimate true exposure. Hair cortisol reflects average levels and may miss acute fluctuations.

Questions This Raises

  • ?Can the cortisol elevation be attributed to cannabis alone or is the tobacco combination necessary?
  • ?Do these cortisol changes persist into adolescence and adulthood?
  • ?What are the behavioral and mental health consequences of this altered HPA-axis functioning?

Trust & Context

Key Stat:
Higher cortisol levels at age 6 linked to prenatal cannabis exposure
Evidence Grade:
Large prospective birth cohort with objective biomarker measurement, though cannabis and tobacco exposure were difficult to separate
Study Age:
Published in 2021. Long-term follow-up of these children could reveal whether cortisol changes persist and affect health outcomes.
Original Title:
Parental cannabis and tobacco use during pregnancy and childhood hair cortisol concentrations.
Published In:
Drug and alcohol dependence, 225, 108751 (2021)
Database ID:
RTHC-03039

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Enrolls participants and follows them forward in time.

What do these levels mean? →

Frequently Asked Questions

Does cannabis use during pregnancy affect children long-term?

This study found children exposed to cannabis (with tobacco) during pregnancy had elevated cortisol levels at age 6, suggesting lasting changes to the stress hormone system. Tobacco alone did not produce this effect.

What does elevated cortisol in children mean?

Higher cortisol levels indicate altered stress hormone regulation. In children, this may increase vulnerability to anxiety, depression, and stress-related conditions, though the specific consequences need further study.

Read More on RethinkTHC

Cite This Study

RTHC-03039·https://rethinkthc.com/research/RTHC-03039

APA

Cajachagua-Torres, Kim N; Jaddoe, Vincent W V; de Rijke, Yolanda B; van den Akker, Erica L T; Reiss, Irwin K M; van Rossum, Elisabeth F C; El Marroun, Hanan. (2021). Parental cannabis and tobacco use during pregnancy and childhood hair cortisol concentrations.. Drug and alcohol dependence, 225, 108751. https://doi.org/10.1016/j.drugalcdep.2021.108751

MLA

Cajachagua-Torres, Kim N, et al. "Parental cannabis and tobacco use during pregnancy and childhood hair cortisol concentrations.." Drug and alcohol dependence, 2021. https://doi.org/10.1016/j.drugalcdep.2021.108751

RethinkTHC

RethinkTHC Research Database. "Parental cannabis and tobacco use during pregnancy and child..." RTHC-03039. Retrieved from https://rethinkthc.com/research/cajachagua-torres-2021-parental-cannabis-and-tobacco

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.