Children exposed to cannabis before birth showed blunted brain reward responses that were associated with psychotic-like experiences, suggesting altered dopamine-related circuitry as a mechanism linking prenatal exposure to psychosis risk.
Pregnant individuals considering cannabis use, child psychiatry researchers, developmental neuroscience audiences
652 prenatally exposed youth tracked over 4 years
What the researchers found
Prenatal cannabis exposure (PCE) was longitudinally associated with psychotic-like experiences in youth. Blunted neural response to reward anticipation was associated with psychotic-like experiences, with stronger effects in PCE-exposed youth (all |beta|>0.5, FDR-corrected p<0.05).
Why it matters
With rising prenatal cannabis exposure rates alongside legalization, understanding the neurobiological mechanisms linking early exposure to later psychiatric symptoms is critical for informing public health guidance for pregnant women.
The numbers in context
652 cannabis-exposed youth out of 11,368 at baseline. Effect sizes |beta|>0.5 for blunted reward response and psychotic-like experiences in PCE youth. Data from 22 sites across the US. Tracked across 4 years.
How the study worked
Longitudinal analysis of the ABCD Study tracking children from age 9-10 across baseline (n=11,368), 2-year (n=7,928), and 4-year (n=2,982) follow-ups. Task-related fMRI measured reward anticipation, and 652 youth had prenatal cannabis exposure.
What this study cannot tell us
Prenatal cannabis exposure was maternally reported and likely underestimated. Cannot fully separate cannabis effects from other prenatal exposures or genetic factors. Attrition reduced sample from 11,368 to 2,982 by 4-year follow-up. Preprint (not yet peer reviewed).
How to read the evidence
Large longitudinal cohort (ABCD Study) with neuroimaging, but observational design, significant attrition, and preprint status.
When this study was published
2024 preprint analyzing ABCD Study longitudinal neuroimaging data
The bigger picture
The endocannabinoid system plays a key role in dopamine signaling and brain reward circuitry development. Prenatal cannabis exposure may alter this system during critical developmental windows, producing measurable changes in reward processing that persist into adolescence.
Questions still open
- Does blunted reward response predict full psychotic disorders or remain at the subclinical level? Could early intervention targeting reward processing reduce psychosis risk in prenatally exposed youth?
Common questions
What is blunted reward response?
How common was prenatal cannabis exposure in this study?
Read the original research
Altered neurobehavioral reward response predicts psychotic-like experiences in youth exposed to cannabis prenatally.
medRxiv : the preprint server for health sciences
Citation
Amir, Carolyn M; Ghahremani, Dara G; Chang, Sarah E; Cooper, Ziva D; Bearden, Carrie E. (2024). Altered neurobehavioral reward response predicts psychotic-like experiences in youth exposed to cannabis prenatally.. medRxiv : the preprint server for health sciences. https://doi.org/10.1101/2024.08.23.24312453
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