Prenatal cannabis exposure linked to blunted brain reward response and psychotic-like experiences in youth

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.

Amir, Carolyn M et al.·medRxiv : the preprint server for health sciences·2024·Moderate Evidencelongitudinal cohort
RTHC-05079Longitudinal cohortModerate Evidence2024RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
longitudinal cohort
Evidence
Moderate Evidence
Sample
N=11,368

What This Study 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).

Key Numbers

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 They Did This

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.

Why This Research 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 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.

What This Study Doesn't 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 Preprint (not yet peer reviewed).

Questions This Raises

  • ?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?

Trust & Context

Key Stat:
652 prenatally exposed youth tracked over 4 years
Evidence Grade:
Large longitudinal cohort (ABCD Study) with neuroimaging, but observational design, significant attrition, and preprint status.
Study Age:
2024 preprint analyzing ABCD Study longitudinal neuroimaging data
Original Title:
Altered neurobehavioral reward response predicts psychotic-like experiences in youth exposed to cannabis prenatally.
Published In:
medRxiv : the preprint server for health sciences (2024)
Database ID:
RTHC-05079

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

What is blunted reward response?

It means reduced brain activation in regions involved in anticipating rewards. This is linked to the dopamine system and has been associated with several psychiatric conditions, including psychosis and depression.

How common was prenatal cannabis exposure in this study?

About 652 out of 11,368 children (roughly 5.7%) had documented prenatal cannabis exposure, based on maternal report.

Read More on RethinkTHC

Cite This Study

RTHC-05079·https://rethinkthc.com/research/RTHC-05079

APA

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

MLA

Amir, Carolyn M, et al. "Altered neurobehavioral reward response predicts psychotic-like experiences in youth exposed to cannabis prenatally.." medRxiv : the preprint server for health sciences, 2024. https://doi.org/10.1101/2024.08.23.24312453

RethinkTHC

RethinkTHC Research Database. "Altered neurobehavioral reward response predicts psychotic-l..." RTHC-05079. Retrieved from https://rethinkthc.com/research/amir-2024-altered-neurobehavioral-reward-response

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.