THC Research

Cannabis shows promise as a therapeutic option for Crohn's disease, demonstrating higher remission rates. However, quality of life was significantly better in the placebo group, highlighting the need for larger, standardized research studies.

In this landmark comparison of 90 trials with 22,028 patients, cannabis was found to be similarly effective to opioids for chronic pain relief, but with a critical advantage: patients on cannabis were 45% less likely to stop treatment due to adverse events compared to those on opioids.

This 2024 systematic review of 15 studies found that most research shows 42-66% pain reduction with CBD or CBD+THC. However, 3 studies found no benefit, and the evidence overall is limited by small study numbers and varied methods.

These 2024 clinical practice guidelines, based on 70 studies, conclude that cannabis-based medicines show "moderate benefit" for chronic pain and also help related conditions like sleep problems and anxiety. The guidelines provide practical dosing and titration recommendations for clinicians.

THC significantly increases heart rate (~17 bpm), arterial stiffness, and reduces cardiac function—effects that could increase cardiovascular risk. CBD did NOT cause these cardiovascular effects. Smoking vs vaping THC made no difference.

Cannabinoids used for medical purposes in children and adolescents were associated with an increased risk of adverse events, including 3x higher withdrawal rates due to adverse events and nearly 2x higher serious adverse events compared to controls.

There was no benefit, perhaps worsened cognition and sleep, and there were many mild adverse events. The brief duration and strong placebo response limits interpretation of effects.

Clinicians should recommend against using cannabis or cannabinoids as a cancer-directed treatment unless within the context of a clinical trial. Cannabis may improve refractory chemotherapy-induced nausea and vomiting when added to standard antiemetics.

This comprehensive umbrella review of 101 meta-analyses found high-certainty evidence that CBD effectively reduces seizures in epilepsy, and cannabis-based medicines help chronic pain (30% pain reduction), MS spasticity, and IBD—but also identified clear risks during pregnancy, for mental health, and while driving.

These consensus guidelines from the American Society of Regional Anesthesia address managing surgical patients who use cannabis. Key points: cannabis users may need higher anesthetic doses, be at increased risk for negative outcomes, and should disclose use to surgical teams.

This 2023 review of 77 articles concludes that medical cannabis provides adequate pain management for chronic nonmalignant pain. THC and CBD work through the endocannabinoid system to reduce pain perception and symptom frequency.

Moderate-certainty evidence shows that nabiximols (THC/CBD spray) and THC are ineffective for relieving moderate-to-severe cancer pain that does not respond to opioids.

Treatment with THC and CBD reduced tics and may reduce impairment due to tics, anxiety, and obsessive-compulsive disorder, although in some participants this was associated with slowed mentation, memory lapses, and poor concentration.

The present study shows minimal benefit of combining dronabinol (10 mg) and hydromorphone (4 mg) for analgesia and improving physical functioning in adults with knee osteoarthritis.

This scoping review found cannabis has been shown useful for both acute and chronic pain, with the strongest evidence for MS-related pain and as an adjunct in cancer pain. However, evidence is weak for neuropathic pain, rheumatic conditions, and headache, and there is no strong evidence for using cannabis to reduce opioid use.

This Cochrane review found that cannabis-based medicines may reduce spasticity and chronic pain in multiple sclerosis, but evidence quality is limited. Nabiximols (Sativex) shows the most evidence for MS spasticity, though side effects are common.

Cannabis withdrawal is real and affects approximately half of regular cannabis users. Symptoms—including anxiety, irritability, sleep problems, and depressed mood—typically start 24-48 hours after stopping and peak at days 2-6. No medications are approved specifically for cannabis withdrawal.

Cannabis users had significantly worse outcomes after surgery: higher pain scores, higher opioid consumption, and more sleep disturbance than non-users. This suggests preoperative cannabis use is a risk factor for postoperative pain.

Cannabinoids are effective therapeutics for several medical indications if their specific pharmacological properties are considered. Different cannabinoids have different evidence levels for different conditions.

Medical cannabis and cannabinoids may improve impaired sleep among people living with chronic pain, but the magnitude of benefit is likely small.

Cannabinoids provide moderate pain relief for chronic neuropathic pain, with patients 1.5 times more likely to experience 30% or greater pain reduction compared to placebo.

Analyzing 32 clinical trials with 5,174 patients, this BMJ meta-analysis found that medical cannabis provides a small but real improvement in chronic pain—about 10% more patients experience meaningful relief compared to placebo. Sleep quality also improved, though side effects like dizziness occur in some patients.

In this controlled trial, a medicinal cannabinoid extract significantly improved chronic insomnia—patients slept over an hour longer and fell asleep 8 minutes faster. Insomnia severity scores improved by 5 points, and patients reported better sleep quality and feeling more rested upon waking.

THC impairs driving performance and increases crash risk, with effects lasting 8 hours or more with oral products. Patients should avoid driving during treatment initiation and for several hours or more after each dose.

The endocannabinoid system (ECS) regulates pain, mood, appetite, memory, and immune function. Because this system is involved in so many conditions—from chronic pain to neurological diseases—cannabis-based medicines have potential for treating diverse disorders.

This meta-analysis of 5 RCTs with 934 patients found NO evidence that cannabis helps cachexia (cancer wasting syndrome). Appetite, weight, and quality of life did not improve compared to placebo. There is currently insufficient evidence to recommend cannabinoids for cachexia.

Evidence for efficacy of these cannabinoid interventions in autism spectrum disorder are mixed and insufficient. Further testing of cannabinoids in ASD is recommended.

All treatment groups, including placebo, showed good tolerability and significant improvements in PTSD symptoms during three weeks of treatment, but no active treatment statistically outperformed placebo in this brief, preliminary trial.

THC may help you fall asleep faster initially, but long-term use can disrupt sleep quality. CBD shows promise for anxiety-related insomnia without the tolerance issues of THC.

In this 8-week controlled trial, women with fibromyalgia taking THC-rich cannabis oil showed significantly improved quality of life scores compared to placebo. Pain, fatigue, ability to work, and overall well-being all improved—with no intolerable side effects.

Cannabis affects the developing adolescent brain differently than adult brains. THC can diminish neuronal growth factors and affect synapse formation, resulting in structural brain changes (grey matter loss) in adolescent users. Early THC use can lead to lasting neuropsychological deficits.

Despite some possible signals for efficacy, the heterogeneity and high risk of bias across included trials do not reliably inform evidence-based practice. High-quality RCTs are required before drawing conclusions about cannabinoid efficacy for insomnia.

Pain intensity of chronic non-cancer patients was reduced by cannabinoids consumption, but effect sizes were small. Efficacy for neuropathic and non-neuropathic pain was similar.

No firm conclusions can be made regarding the safety and effectiveness of cannabis and cannabinoids in adults with Crohn's disease and ulcerative colitis.

81.1% of fibromyalgia patients reported significant improvement after 6 months of medical cannabis treatment, with 73% achieving at least moderate improvement in pain.

This comprehensive Lancet Psychiatry analysis of 83 studies found scarce evidence that cannabis helps mental health conditions. The only modest benefit was for anxiety in people already using cannabis for other conditions like chronic pain—and even this evidence was very low quality.

This Dutch trial compared four cannabis varieties in fibromyalgia patients and found unexpected results: while balanced THC/CBD produced the most pain relief, adding CBD to THC actually reduced THC's pain-relieving effects. THC-containing varieties improved pressure pain tolerance, but effects were modest overall.

Cannabis has both therapeutic potential and documented risks. While cannabinoids show promise for neurological and psychiatric conditions, repeated use is associated with respiratory, cardiovascular, cognitive, and psychiatric adverse effects. The evidence requires careful weighing of benefits against harms.

Cancer patients in Minnesota's medical cannabis program showed significant improvement across ALL 8 symptoms tracked—anxiety, appetite, depression, sleep, fatigue, nausea, pain, and vomiting—within 4 months. Only 10.5% reported adverse effects.

Nabiximols had a positive effect on spasticity symptoms in patients with motor neuron disease and had an acceptable safety and tolerability profile. This is the first positive proof-of-concept trial for cannabinoids in ALS spasticity.

The high prevalence of adolescents consuming cannabis generates a large number of young people who could develop depression and suicidality attributable to cannabis. This is an important public health problem.

This Cochrane review of 16 studies found that cannabis-based medicines provide modest pain relief for neuropathic pain—about 1 in 11 patients achieve meaningful improvement. However, side effects are common, with nervous system and psychiatric effects occurring more frequently than with placebo.

This rigorous meta-analysis of 104 studies found cannabis provides modest pain relief—about 1 in 24 patients benefit—but with a high side effect burden: 1 in 6 experience harm. The authors concluded it "seems unlikely that cannabinoids are highly effective medicines" for chronic pain.

The effects of cannabis and cannabis oil on Crohn's disease are uncertain. No firm conclusions regarding efficacy and safety can be drawn from the available evidence.

There is reasonable evidence that cannabinoids improve nausea and vomiting after chemotherapy. They might improve spasticity. There is uncertainty about whether they improve pain, but if they do, it is neuropathic pain and the benefit is likely small. Adverse effects are very common.

There is conclusive or substantial evidence that cannabis or cannabinoids are effective for chronic pain in adults, chemotherapy-induced nausea and vomiting, and spasticity associated with multiple sclerosis. Evidence for most other conditions is limited, insufficient, or absent.

97% of patients agreed or strongly agreed that cannabis helped them decrease the amount of opioids they use, with 92% preferring cannabis over opioids for pain management.

Cannabis-based medicines might be effective for chronic pain treatment, based on limited evidence, primarily for neuropathic pain patients. However, the clinical significance of these findings is uncertain as the majority of studies did not show an effect.

Selective cannabinoids provide a small analgesic benefit in patients with chronic neuropathic pain.

Migraine patients using medical cannabis saw their monthly headache frequency drop from 10.4 to 4.6—a reduction of more than half—with 40% reporting at least 50% fewer migraines.

There is no convincing, unbiased, high quality evidence suggesting that nabilone is of value in treating people with fibromyalgia. The tolerability of nabilone was low in people with fibromyalgia.

Currently, there is insufficient evidence for recommendation for any cannabinoid preparations for symptom management in patients with chronic pain associated with rheumatic diseases.

This comprehensive review of 79 trials found moderate-quality evidence that cannabinoids are effective for chronic pain and spasticity, with most studies showing improvement in symptoms.

Military personnel with PTSD who took nabilone (a synthetic THC) experienced significant reduction in nightmare frequency, with 70% reporting reduced nightmares or completely stopping them.

In this Cochrane review of 23 trials, cannabinoids were nearly 6 times more effective than placebo at completely stopping chemotherapy-induced vomiting. Patients overwhelmingly preferred cannabis-based treatments, though side effects like feeling "high" and dizziness were common.

Inhaled cannabis may provide short-term relief for 1 in 5 to 6 patients with neuropathic pain. Number needed to treat = 5.6. Pragmatic trials are needed to evaluate long-term benefits and risks.

45% of Crohn's patients achieved complete clinical remission with cannabis compared to 10% on placebo, and 90% showed significant clinical response.

Long-term use of THC/CBD spray was generally well tolerated, with no evidence of a loss of effect for the relief of cancer-related pain with long-term use. Patients did not seek to increase their dose over time, suggesting no tolerance development.

Smoked cannabis was superior to placebo in symptom and pain reduction in participants with treatment-resistant spasticity. Future studies should examine whether different doses can result in similar beneficial effects with less cognitive impact.

Patients with MS who responded to initial cannabis spray treatment achieved twice the spasticity relief compared to placebo in this large Phase III trial.

THC:CBD extract is efficacious for relief of pain in patients with advanced cancer pain not fully relieved by strong opioids. THC alone showed no significant benefit over placebo.