A large study published in Molecular Psychiatry reveals that cannabis exposure during pregnancy may influence brain connectivity and behavioural outcomes in children, raising concerns about long-term neurodevelopmental effects.
A large study in Molecular Psychiatry suggests that cannabis exposure in pregnancy may be linked not only to later behavioural and cognitive differences in children, but also to measurable changes in how the brain is wired in late childhood. Using data from more than 10,800 children in the Adolescent Brain Cognitive Development study, researchers found that children exposed to cannabis before birth had higher levels of psychopathology and showed differences across several cognitive tests, compared with unexposed peers.
The analysis separated exposure that occurred before and after the mother became aware of the pregnancy and used resting-state functional MRI to examine large-scale brain network connectivity. The exposed group made up 751 children, or 6.93% of the sample. According to the study, prenatal cannabis exposure was associated with altered connectivity patterns across multiple networks, alongside generally lower performance on most cognitive measures, although one composite measure of fluid cognition was higher.
The most notable finding was that the connectivity patterns tied to prenatal cannabis exposure also overlapped with patterns linked to mental health symptoms and cognitive performance. In other words, the same network differences that appeared in exposed children were, in part, associated with the behavioural and cognitive outcomes the researchers measured. The authors said this raises the possibility that altered functional connectivity could be one pathway connecting prenatal cannabis exposure with later neurodevelopmental risk, though they stressed that not all brain-behaviour links were explained by exposure.
The new paper adds to a growing body of evidence pointing in the same direction. A preprint on human fetal brain tissue suggested prenatal cannabis use may affect neurodevelopment at the molecular level, while a separate scoping review found major methodological gaps in the wider literature on perinatal cannabis exposure. Other recent cohort studies, including work from the HEALthy Brain and Child Development study, have reported associations between prenatal cannabis exposure and differences in neonatal brain development as well as birth outcomes. Taken together, the findings strengthen concern that cannabis use during pregnancy may carry risks that extend beyond birth and into childhood development.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
