Two longitudinal studies found that prenatal cannabis exposure was associated with DNA methylation changes in genes involved in brain development, detectable at birth, age 7, age 15-17, and age 27.
Epigenetics researchers, developmental neuroscientists, obstetricians counseling pregnant patients about cannabis.
Prenatal cannabis exposure left DNA methylation marks in brain development genes through age 27
What the researchers found
Prenatal cannabis exposure was associated with genome-wide significant DNA methylation differences at birth, 7 years, 15-17 years, and 27 years. Several genes (LZTS2, NPSR1, NT5E, CRIP2, DOCK8, COQ5, LRP5) showed shared methylation changes across multiple time points. Functional pathway analysis consistently showed enrichment for neurodevelopment, neurotransmission, and neuronal structure pathways across all timepoints in both cohorts.
Why it matters
This is among the most comprehensive evidence that prenatal cannabis exposure creates lasting epigenetic changes in offspring. The persistence of changes from birth through age 27, replicated across two cohorts and two countries, strengthens the case that prenatal cannabis exposure has long-term biological consequences.
The numbers in context
Two cohorts (ALSPAC UK, CHDS New Zealand); DNA methylation assessed at 0, 7, 15-17, and 27 years; 7 genes showed shared changes across multiple timepoints; neurodevelopment pathways enriched across all timepoints.
How the study worked
Epigenome-wide association study using two longitudinal cohorts: ALSPAC (UK, examined at 0, 7, and 15-17 years) and CHDS (New Zealand, examined at ~27 years). Examined DNA methylation differences associated with prenatal cannabis exposure alone and co-exposure with tobacco.
What this study cannot tell us
Cannot prove that methylation changes cause functional problems. Prenatal exposure is based on maternal self-report. Cannot fully separate cannabis effects from tobacco co-exposure or other confounders. Different cohorts and timepoints used different methylation platforms.
How to read the evidence
Strong: Multi-cohort, multi-timepoint epigenome-wide study replicated across two countries (UK and New Zealand) with consistent pathway enrichment at every age examined.
When this study was published
Published in 2025 using longitudinal data spanning birth to age 27.
The bigger picture
Epigenetics represents a mechanism by which environmental exposures during pregnancy can have lasting effects on offspring without changing the DNA sequence itself. This study provides a molecular link between the epidemiological evidence of prenatal cannabis effects and the neurodevelopmental outcomes observed in exposed children.
Questions still open
- Do the identified methylation changes actually translate to altered gene expression and brain function? Are these changes reversible, or do they persist throughout life? Could epigenetic markers serve as biomarkers for prenatal cannabis exposure?
Common questions
What is DNA methylation?
Does this mean prenatal cannabis permanently changes a child's DNA?
Read the original research
Prenatal cannabis exposure is associated with alterations in offspring DNA methylation at genes involved in neurodevelopment, across the life course.
Molecular psychiatry, 30(4), 1418-1429
Citation
Noble, Alexandra J; Adams, Alex T; Satsangi, Jack; Boden, Joseph M; Osborne, Amy J. (2025). Prenatal cannabis exposure is associated with alterations in offspring DNA methylation at genes involved in neurodevelopment, across the life course.. Molecular psychiatry, 30(4), 1418-1429. https://doi.org/10.1038/s41380-024-02752-w
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