Mice exposed to cannabis before birth and then stressed during adolescence showed significantly more risk-taking behavior than mice exposed to either factor alone.
Developmental neuroscience researchers, parents interested in prenatal exposure effects, and adolescent health professionals.
Combined exposure increased risk-taking; neither factor alone did
What the researchers found
Prenatal cannabis exposure alone did not significantly affect anxiety, stress coping, or social behavior. However, when combined with chronic adolescent stress, mice showed significantly increased risk-taking behavior on the wire beam bridge task. Sex differences in prefrontal cortex c-Fos expression suggested different neural responses to the combined exposure.
Why it matters
Many children prenatally exposed to cannabis also grow up in stressful environments. This study shows these two factors may interact to produce behavioral effects that neither causes alone, specifically increased risk-taking.
The numbers in context
THC dose: 5 mg/kg daily from GD1-PD10. Adolescent stress: PD28-56. Behavioral testing: PD58+. Co-exposed mice had significantly increased bridge crossing (risk-taking). Sex differences found in prefrontal cortex c-Fos expression.
How the study worked
Mouse dams consumed 5 mg/kg THC in whole cannabis oil daily from gestational day 1 through postnatal day 10. Offspring underwent chronic mild unpredictable stress throughout adolescence (PD28-56) and were tested on a battery of behavioral tasks starting at PD58.
What this study cannot tell us
Animal study using oral whole cannabis oil, which differs from typical human consumption. Mouse behavior may not translate to human risk-taking. The stress paradigm (chronic mild unpredictable stress) is standardized but artificial.
How to read the evidence
Well-controlled animal study with dose-controlled exposure, but translating mouse behavioral tests to human risk-taking is uncertain.
When this study was published
2026 animal study.
The bigger picture
The interaction between prenatal cannabis exposure and later-life stress aligns with the broader two-hit hypothesis in psychiatry, where early biological vulnerabilities combine with later environmental stressors to produce adverse outcomes that neither hit causes independently.
Questions still open
- Does prenatal cannabis exposure sensitize the developing brain to later stress in humans? Could the sex differences in prefrontal cortex responses explain different vulnerability patterns in boys versus girls?
Common questions
Does prenatal cannabis exposure make kids take more risks?
Were there sex differences?
Read the original research
Prenatal and early postnatal cannabis exposure interactions with adolescent chronic stress on anxiety-like, depression-like, and risk-taking behaviour.
Psychopharmacology, 243(2), 339-368
Citation
Peterson, Colleen S; Ifionu, Ijeoma; Hamood, Fatima; Semizeh, Hadi; Ali, Ahmad; Noble, Duncan; Qiao, Min; Borgland, Stephanie L. (2026). Prenatal and early postnatal cannabis exposure interactions with adolescent chronic stress on anxiety-like, depression-like, and risk-taking behaviour.. Psychopharmacology, 243(2), 339-368. https://doi.org/10.1007/s00213-025-06822-x
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