Welcome to Business of Cannabis’ new research digest, unpacking the latest clinical evidence shaping cannabis therapeutics.
While headlines often focus on regulatory shifts and market access, the scientific foundation underpinning medical cannabis continues to evolve at a pace, yet rigorous clinical trial data rarely receive the attention it deserves outside academic circles.
With optimism that the US could reschedule cannabis in the coming months, cannabis research could see a wave of investment flood through the research sector, having major implications for its integration into mainstream healthcare.
Beyond the Abstract aims to cut through PR-hype and methodological complexity to deliver a clear-eyed analysis of emerging research, from pain management and neurological conditions to rare disease applications. We’ll examine what the data actually shows, where evidence gaps remain, and how new findings might influence clinical practice and regulatory frameworks across Europe and beyond.
This edition launches with three landmark studies published in recent months: a major systematic review on cannabis for chronic pain, the first randomised controlled trial of vaporised cannabis for acute migraine, and new data on CBD-rich formulations for ADHD symptoms in children with autism spectrum disorder.
For comprehensive access to the latest cannabis clinical trials across chronic pain, epilepsy, oncology, and other therapeutic areas, explore Business of Cannabis’ Cannabis Research Repository, a continuously updated database of human studies, systematic reviews, and real-world evidence.
Cannabis for chronic pain comparable to opioids
A comprehensive systematic review from Oregon Health & Science University has quantified cannabis efficacy for chronic pain, revealing stark differences between THC and CBD-dominant products.
The study, ‘Living Systematic Review on Cannabis and Other Plant-Based Treatments for Chronic Pain: 2025 Update’, marked the fourth and final annual update of the ‘living review’, which continually adapted to ‘identify and synthesise’ new literature as it was published.
It analysed 25 randomised controlled trials (RCTs) involving 2,303 patients, predominantly those with neuropathic pain, finding that high-THC products reduced pain severity by 0.78 points on a 10-point scale compared to placebo. Products with comparable THC-to-CBD ratios performed slightly worse, showing reductions of 0.54 points.
Despite both being THC-based pharmaceuticals, Nabilone demonstrated moderate pain reduction of 1.59 points on a 0-10 scale, while Dronabinol showed minimal effect at just 0.23 points, a statistically significant difference.
Across four RCTs involving 334 patients, synthetic or purified CBD alone was ‘not associated with decreased pain intensity’ versus placebo, with the pooled mean difference actually favouring placebo by 0.40 points (95% CI −0.14 to 1.00). CBD also showed no benefit in terms of function or pain response rates.
Nabiximols (Sativex), and oromucosal spray containing 2.7mg THC and 2.5mg CBD per spray, showed pain reduction of 0.54 points and functional improvement of 0.42 points, both ‘just below the threshold for a small effect’ according to the review’s criteria.
High-THC products carried substantial risks, as evidenced by dizziness in 33% of cases versus 15% with the placebo (relative risk [RR] 2.20), sedation in 24% vs. 16% (RR 1.50), and withdrawal due to adverse events in 14% vs. 7% (RR 1.92).
All 25 trials were short-term only (1-6 months), predominantly enrolled neuropathic pain patients (64%), with mean age 53 years. The review found ‘insufficient evidence’ on cannabis use disorder development, long-term outcomes, or effects beyond neuropathic pain.
The review notes that cannabis products’ pain reduction appears ‘comparable to those observed with prescription opioids, several nonopioid medications, and nonpharmacological interventions,’ though the authors emphasise this cross-trial comparison ‘must be done with extreme caution’ and head-to-head trials are needed.
First RCT shows CBD & THC combination beats placebo for acute migraine
The first randomised, double-blind, placebo-controlled trial of cannabis for acute migraine has demonstrated that vaporised THC combined with CBD outperforms placebo, but in similar findings to the systematic review above, CBD alone shows little benefit.
University of California San Diego researchers enrolled 92 participants who treated 247 migraine attacks with four different vaporised cannabis treatments in randomised order: 6% THC, 11% CBD, 6% THC plus 11% CBD, or placebo.
The THC+CBD combination achieved the primary outcome of 2-hour pain relief in 67% versus 47% with placebo (OR 2.85, p=0.016). Critically, it also met secondary endpoints of pain freedom (35% vs 16%, p=0.017) and most bothersome symptom freedom (60% vs 35%, p=0.005), benefits that persisted at 24 and 48 hours.
THC alone achieved pain relief (69% vs 47%, p=0.008) but failed to reach statistical significance for pain freedom or symptom relief at two hours and showed no sustained benefits. CBD alone demonstrated no superiority to placebo on any measure.
The combination reduced photophobia and phonophobia but not nausea, confirming ‘antimigraine effects rather than THC’s established antiemetic effects.’ Mean subjective highness was lower with THC+CBD (2.4/10) than THC alone (3.5/10), consistent with CBD’s role as a negative allosteric modulator of CB1 receptors.
Researchers noted critical limitations, including single-dose testing (no data on medication overuse headache or cannabis use disorder with repeated use), NIDA cannabis devoid of terpenes and minor cannabinoids, and pain relief rather than pain freedom as the primary endpoint, contrary to current International Headache Society guidelines.
SOMAÍ and Universidade Lusófona Publish Peer-Reviewed Study Validating Full-Spectrum Oil Consistency
CBD-rich cannabis shows behavioural improvement in children with ADHD and ASD
An open-label study from Tel Aviv University has reported behavioural improvements in children with autism and ADHD following CBD-rich cannabis treatment, though the lack of placebo control limits conclusions about causation.
Researchers evaluated 53 children and young adults using the Conners’ Teacher Rating Scale before and after 3-6 months of CBD-rich cannabis oil. Teachers reported statistically significant improvements in anxious-shyness, perfectionism, ADHD index scores, emotional lability, and hyperactive-impulsivity.
Blood analysis revealed no consistent relationship between CBD concentrations and most behavioural changes, except for emotional regulation. Higher CBD levels correlated with greater improvements in emotional lability, suggesting a possible dose-response effect.
The study represents ‘the first prospective study to evaluate the effects of CBD-rich cannabis on ADHD symptoms in children with ASD using standardised teacher-based assessments,’ addressing concerns that parent-reported outcomes may be influenced by expectation bias.
However, the open-label design, where all participants knew they were receiving active treatment, substantially limits interpretation. Authors acknowledge this ‘limits the ability to draw firm conclusions about causation’ and emphasise ‘the need for randomised, controlled trials to confirm efficacy.’
A separate 2025 UC San Diego placebo-controlled trial testing purified CBD (Epidiolex) up to 20mg/kg/day in autistic boys found no significant difference between CBD and placebo groups on behavioural measures, with both groups improving equally, suggesting open-label improvements may reflect placebo effects, natural symptom variation, or regression to the mean rather than pharmacological action
