Children exposed to marijuana before birth showed more behavioral problems by age 3.5

In a prospective cohort study, children exposed to marijuana during pregnancy showed more sleep problems, withdrawal symptoms, externalizing behaviors, and aggressive/oppositional behaviors at age 3.5, but no differences in executive functioning.

Murnan, Aaron W et al.·Journal of applied developmental psychology·2021·Moderate EvidenceProspective Cohort
RTHC-03369Prospective CohortModerate Evidence2021RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Prospective Cohort
Evidence
Moderate Evidence
Sample
N=63

What This Study Found

Compared to non-exposed children, those with prenatal marijuana exposure had significantly more sleep-related problems, withdrawal symptoms, externalizing problems including aggressive behaviors and oppositional defiant behaviors at age 3.5. Executive functioning did not differ between groups.

Key Numbers

63 children assessed at age 3.5; prenatal exposure from self-report + medical chart + urine toxicology; significant differences in sleep, withdrawal, externalizing, aggression, and oppositional behaviors; no differences in executive function

How They Did This

Prospective prenatal cohort in Columbus, Ohio. Prenatal marijuana exposure was determined from maternal self-report, medical chart abstraction, and urine toxicology. At age 3.5, 63 children completed tasks assessing executive function, visual-spatial ability, emotion regulation, and aggressive behavior. Caregivers reported on behavior.

Why This Research Matters

Today's marijuana is significantly more potent than in previous decades, making earlier studies on prenatal exposure potentially less relevant. This cohort was exposed to contemporary, higher-potency marijuana, providing more current data on early childhood outcomes.

The Bigger Picture

The finding that behavioral problems are detectable by age 3.5 but cognitive differences are not suggests prenatal marijuana exposure may affect emotional regulation and behavior before measurably affecting cognitive development.

What This Study Doesn't Tell Us

Small sample of 63 children. Cannot fully control for other prenatal exposures and socioeconomic factors that correlate with marijuana use. Self-reported exposure may underestimate actual use. Single assessment at 3.5 years.

Questions This Raises

  • ?Will executive function differences emerge at older ages?
  • ?Are these behavioral effects permanent or transient?
  • ?Does the dose and timing of prenatal exposure affect outcomes?
  • ?How does prenatal marijuana exposure interact with postnatal environment?

Trust & Context

Key Stat:
More sleep problems, aggression, and oppositional behavior at age 3.5 with prenatal exposure
Evidence Grade:
Prospective design with multiple exposure verification methods, but small sample and potential confounding.
Study Age:
Published in 2021.
Original Title:
Behavioral and Cognitive Differences in Early Childhood related to Prenatal Marijuana Exposure.
Published In:
Journal of applied developmental psychology, 77 (2021)
Database ID:
RTHC-03369

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 prenatal marijuana exposure affect children's behavior?

This study found children exposed before birth had more sleep problems, withdrawal symptoms, and aggressive/oppositional behaviors at age 3.5, though executive functioning was not affected.

Is today's marijuana more concerning during pregnancy?

The researchers note that today's marijuana is significantly more potent than what was studied in earlier decades, making these findings on contemporary exposures particularly relevant.

Read More on RethinkTHC

Cite This Study

RTHC-03369·https://rethinkthc.com/research/RTHC-03369

APA

Murnan, Aaron W; Keim, Sarah A; Yeates, Keith Owen; Boone, Kelly M; Sheppard, Kelly W; Klebanoff, Mark A. (2021). Behavioral and Cognitive Differences in Early Childhood related to Prenatal Marijuana Exposure.. Journal of applied developmental psychology, 77. https://doi.org/10.1016/j.appdev.2021.101348

MLA

Murnan, Aaron W, et al. "Behavioral and Cognitive Differences in Early Childhood related to Prenatal Marijuana Exposure.." Journal of applied developmental psychology, 2021. https://doi.org/10.1016/j.appdev.2021.101348

RethinkTHC

RethinkTHC Research Database. "Behavioral and Cognitive Differences in Early Childhood rela..." RTHC-03369. Retrieved from https://rethinkthc.com/research/murnan-2021-behavioral-and-cognitive-differences

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.