Children born with fetal alcohol spectrum disorder face a lifetime of emotional instability, learning difficulties, and heightened addiction risk. There’s no drug that targets the biological roots of the condition. Now researchers in Spain report that cannabidiol, the non-psychoactive compound in cannabis, reversed key effects of prenatal alcohol exposure in mice, including anxiety-like behavior, addiction vulnerability, and disrupted gut bacteria.
The study, published in Biomedicine & Pharmacotherapy, found that chronic CBD treatment starting at weaning normalized emotional behavior in both male and female mice exposed to alcohol during development. In females, the treatment completely eliminated their heightened motivation to consume alcohol, bringing it back to the level of healthy controls.
Fetal alcohol spectrum disorder, or FASD, is the leading preventable cause of intellectual disability worldwide. Alcohol exposure in the womb disrupts brain development, leaving lasting damage to emotion regulation and reward processing. Despite affecting millions, there are no approved medications that address the disorder’s underlying biology, only symptomatic interventions.
Repairing the Brain’s Reward Circuitry
The research team at the Institute for Neurosciences focused on the endocannabinoid system, a signaling network that helps regulate emotion, motivation, and stress response. Previous work showed this system gets thrown off balance by prenatal alcohol exposure.
CBD treatment corrected molecular changes in the brain’s reward center, normalizing dopamine receptors and endocannabinoid system components that had been disrupted. These aren’t abstract markers. They’re the machinery that determines how the brain processes pleasure, manages stress, and regulates emotional responses.
“Despite its enormous social and health impact, there is currently no approved pharmacological treatment that targets the root of the disorder,” Jorge Manzanares explains.
Both male and female mice showed anxiety-like and depressive-like behaviors after prenatal alcohol exposure. CBD erased these behaviors in both sexes. But the female response was particularly striking—their motivation to self-administer alcohol dropped to normal levels, suggesting the treatment repaired damage to reward and stress systems.
The Gut’s Role in Brain Damage
Prenatal alcohol doesn’t just damage the brain. It causes long-term dysbiosis—an imbalance of bacteria in the digestive system that appears to worsen emotional distress through the gut-brain axis.
CBD reversed these changes. The treatment increased beneficial bacteria like Akkermansia and Bifidobacterium, which are known for anti-inflammatory properties and maintaining a healthy gut lining. Microbial diversity, which had been disrupted by alcohol exposure, was restored.
The gut effects differed between males and females, reflecting natural sex differences in microbiota composition. This suggests future FASD treatments might need sex-specific approaches.
“Our data suggest that part of the sex differences in vulnerability to FASD may originate in the gut rather than exclusively in the brain,” Francisco Navarrete explains.
The researchers are careful to note this is a preclinical model. They’re not suggesting CBD can counteract alcohol consumption during pregnancy or that it’s a cure. But the work offers a roadmap for developing the first pharmacological treatments that target FASD’s underlying causes rather than just managing symptoms. For now, total abstinence from alcohol during pregnancy remains the only proven protection.
DOI: https://doi.org/10.1016/j.biopha.2025.118791
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