CBD showed anticonvulsant, anxiolytic, antipsychotic, and anti-addictive properties in preclinical and limited clinical studies, but well-powered controlled trials were lacking for all indications.
Read this if you want to understand the scientific foundation for CBD as a medicine.
CBD showed therapeutic potential across epilepsy, anxiety, psychosis, and addiction
What the researchers found
This landmark review by leading researchers summarized the evidence for CBD across multiple neuropsychiatric conditions. Key findings by indication:
Epilepsy: CBD was anticonvulsant in most animal models. Human evidence was limited to small, uncontrolled studies and anecdotal reports. The antiepileptic mechanisms were not fully understood but involved multiple receptor and channel targets. Trials targeting Dravet and Lennox-Gastaut syndromes were being planned.
Anxiety and psychosis: Preclinical and early clinical evidence supported anxiolytic and antipsychotic properties. CBD appeared well tolerated without the psychoactive effects of THC.
Addiction: Early evidence suggested CBD might reduce drug-seeking behavior through effects on multiple neurotransmitter systems.
Across all conditions, the review concluded that well-powered, double-blind, randomized controlled trials were needed.
Why it matters
This review, published in the leading epilepsy journal by an author team that included key figures in subsequent CBD clinical development, established the scientific framework that guided the clinical trial program leading to FDA approval of Epidiolex.
The numbers in context
Multiple receptor targets identified for CBD anticonvulsant effects. CBD appeared well tolerated in available human data. No well-powered RCTs existed for any CBD indication at the time of publication.
How the study worked
Expert review summarizing presentations from a scientific conference where invited participants reviewed CBD physiology, mechanisms of action, pharmacology, animal model data, and human studies.
What this study cannot tell us
Available human evidence was small-scale and methodologically limited. CBD mechanisms of action were not fully characterized. Drug interactions with antiepileptic medications were unknown. Long-term safety data were lacking.
How to read the evidence
Expert review by leading researchers synthesizing preclinical and limited clinical evidence. Subsequent trials confirmed the epilepsy indication.
When this study was published
Published in 2014. CBD (Epidiolex) received FDA approval for epilepsy in 2018.
The bigger picture
This paper marked a turning point in cannabinoid medicine: the moment when the scientific community formally acknowledged sufficient preclinical evidence to justify rigorous human testing of CBD. The subsequent clinical trials confirmed anticonvulsant efficacy and led to regulatory approval.
Questions still open
- Most questions raised by this review have since been partially answered: CBD proved effective for Dravet and Lennox-Gastaut syndromes. Questions about optimal dosing, drug interactions, and long-term effects continue to be studied.
Common questions
What conditions might CBD help treat?
Is CBD the same as medical marijuana?
Read the original research
Cannabidiol: pharmacology and potential therapeutic role in epilepsy and other neuropsychiatric disorders.
Epilepsia, 55(6), 791-802
Citation
Devinsky, Orrin; Cilio, Maria Roberta; Cross, Helen; Fernandez-Ruiz, Javier; French, Jacqueline; Hill, Charlotte; Katz, Russell; Di Marzo, Vincenzo; Jutras-Aswad, Didier; Notcutt, William George; Martinez-Orgado, Jose; Robson, Philip J; Rohrback, Brian G; Thiele, Elizabeth; Whalley, Benjamin; Friedman, Daniel. (2014). Cannabidiol: pharmacology and potential therapeutic role in epilepsy and other neuropsychiatric disorders.. Epilepsia, 55(6), 791-802. https://doi.org/10.1111/epi.12631
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