What Thousands of Scientific Papers Reveal
A bibliometric analysis of Cannabis sativa research trends, challenges, and future directions
In 1843, a British physician named William O'Shaughnessy published a revolutionary paper describing how cannabis extracts could treat patients suffering from tetanus, hydrophobia, and cholera 3 . This groundbreaking study marked one of the first scientific investigations into cannabis's medicinal properties—but for nearly a century after, legal restrictions would severely limit research into this controversial plant 3 .
Bibliometrics is the statistical analysis of scientific publications that allows researchers to examine vast collections of studies simultaneously, revealing patterns in research landscapes 4 .
Cannabis has been used medicinally for thousands of years, but its journey through the scientific literature has been anything but straightforward. Analysis of research trends reveals four distinct periods in how scientists have approached this complex plant 3 :
Cannabis mentioned primarily as a botanical curiosity, with most reports focusing on hemp fiber quality and occasional references to traditional medicines 3 .
Beginning with O'Shaughnessy's systematic investigation of Cannabis indica, this evidence-based approach opened the door to serious scientific inquiry 3 .
Strict legal classifications severely limited cannabis studies, relegating the plant to the category of illicit drug with few scientists exploring potential benefits 3 .
Beginning when California became the first state to legalize medical cannabis in 1996, this policy shift triggered an unprecedented research explosion that continues today 3 .
The numbers behind the cannabis research boom are striking. A comprehensive bibliometric analysis published in 2022 identified 29,802 scientific publications on cannabis and cannabinoids published between 1829 and 2021 4 .
Annual increase in publications (2012-2022) 2
Publications from the United States 4
Peak publications in 2021 1
The United States has dominated cannabis research, producing 12,420 publications—far surpassing the second and third most productive countries, the United Kingdom (2,236) and Canada (2,062) 4 . This geographic concentration reflects both the early legalization of medical cannabis in these countries and the significant research funding allocated to cannabinoid studies.
Bibliometric analysis reveals fascinating patterns in what aspects of cannabis scientists choose to study. The research has traditionally clustered in several key domains:
| Research Domain | Percentage | Primary Focus |
|---|---|---|
| Pharmacology & Pharmacy | 31.7% | Therapeutic applications, drug development 8 |
| Neuroscience | 16.24% | Neurological effects, brain mechanisms 8 |
| Clinical Neurology | 12.17% | Treating neurological disorders |
| Psychiatry | 10.90% | Mental health applications |
| Biochemistry & Molecular Biology | 7.88% | Fundamental plant biology 1 8 |
Perhaps the most significant trend has been the shift in focus from recreational use and abuse potential toward medical applications. Recent years have seen growing research into therapeutic applications for conditions including epilepsy, anxiety, schizophrenia, and chronic pain 8 .
A dedicated bibliometric analysis of CBD research identified 3,555 publications between 2004 and 2021, with remarkable growth following the 2018 FDA approval of Epidiolex for treating seizure disorders 8 .
To understand how bibliometric analysis actually works, let's examine a recent landmark study that exemplifies the approach. Published in 2024 in Cannabis and Cannabinoid Research, this study aimed to comprehensively map the entire field of cannabis research 1 .
The research team followed a systematic protocol registered in the International Prospective Register of Systematic Reviews to ensure scientific rigor 1 .
The analysis revealed that research productivity peaked in 2021 with 1,481 publications—a reflection of the growing interest and investment in cannabis science 1 .
The study identified significant knowledge gaps, particularly in the areas of "Neurosciences" (1.59% of publications) and "Biochemistry, Genetics, and Molecular Biology" (0.79%) relative to their importance in understanding cannabis's effects and improving cultivation 1 .
Modern cannabis bibliometric research relies on a sophisticated array of digital tools and databases that enable scientists to process thousands of publications simultaneously 1 4 .
Comprehensive publication database with global coverage
DatabaseCitation indexing and search platform
DatabaseConstructing and visualizing bibliometric networks
SoftwareVisualizing trends and patterns in scientific literature
SoftwareAnalyzing temporal, spatial, and network data
SoftwareBiomedical and life sciences literature
DatabaseThese resources allow researchers to move beyond simple publication counts to analyze citation networks (which papers influence others), co-authorship patterns (collaboration networks), and keyword co-occurrence (how research topics relate to each other) 4 . For example, by analyzing which terms frequently appear together, researchers can identify emerging subfields before they become widely recognized.
Bibliometric analysis does more than document the past—it helps predict the future. Based on current trends and identified gaps, several promising research directions are emerging 1 2 :
The focus will likely continue shifting from recreational use and adverse effects toward therapeutic applications, particularly for neurological disorders, pain management, and mental health conditions 8 .
The relatively under-explored areas of cannabis genetics and biochemistry represent significant opportunities, especially with advances in genomic technologies that could revolutionize crop improvement and compound production 3 .
While the U.S., U.K., and Canada currently dominate cannabis research, countries like Morocco have shown recent steady growth (14.31% annual growth rate) and high international collaboration rates (51.72%), suggesting a globalization of cannabis science 2 .
As the field matures, research is becoming more specialized, with increased focus on specific cannabinoids (like CBD), their mechanisms of action, and potential applications 8 .
Future studies will likely focus more on translating research findings into practical guidelines for medical use, cultivation standards, and regulatory frameworks 2 .
Bibliometric analysis has revealed both the remarkable growth and the significant imbalances in cannabis research. From a handful of studies in the 19th century to thousands of papers annually, the scientific journey of cannabis reflects our evolving understanding of this complex plant—from illicit substance to promising medicine.
As research continues to expand, bibliometric methods will become increasingly valuable for navigating the flood of new studies and ensuring that limited research resources are directed toward the most promising areas. For students considering entering the field, clinicians seeking evidence-based guidance, or investors evaluating emerging trends, these analytical approaches offer invaluable maps to the evolving landscape of cannabis science.
The journey of cannabis research—from botanical curiosity to controversial drug to promising medicine—demonstrates how science can evolve when provided with the freedom to explore. Thanks to bibliometric analysis, we can now trace this journey not through anecdotes, but through the objective evidence of thousands of scientific publications, each adding another piece to our understanding of one of humanity's oldest, yet most recently rediscovered, medicinal plants.