Cannabis houses approximately 100 molecular compounds called cannabinoids. Cannabidiol (CBD) is the second most abundant of these cannabinoids. The most widely researched cannabinoid has been THC, but the scientific and medical community’s discovery of CBD’s medical efficacy has inspired a concentration of research on how to use CBD to treat an array of disorders.
CBD Is Not An Intoxicant
A cannabinoid’s effects are created by its interactions with the molecular pathways that exist in mammalian bodies. THC primarily interacts with CB1, a cannabinoid receptor that assists in regulating pain sensation, memory, sleep, mood, and appetite. THC’s interaction with CB1 causes cannabis consumers to feel high.
CBD produces different results in consumers because it interacts with different molecular pathways than THC does. These molecular pathways include the serotonin receptor, vanilloid receptors, GPR55, and nuclear receptor. CBD also modulates allosteric receptors and inhibits the reuptake of endogenous neurotransmitters. CBD’s interactions with these molecular pathways make the cannabinoid an effective medical therapy, but they do not create any psychoactive effects. In fact, a 2015 British Journal of Pharmacology study found that CBD’s ability to modulate allosteric receptors decreases the potency of THC’s psychoactive effects.
CBD’s Side Effects
Cannabis and Cannabinoid Research published a 2017 literature review of the evidence surrounding the safety and side effects of CBD.
The review found that the most commonly reported CBD side effects were:
- appetite and weight changes.
In contrast to more conventional therapies used to treat the same disorders CBD was being used to treat in these studies, the side effects were mild. The researchers concluded that, though CBD’s side effect profile is promising, more research needs to be done on CBD’s toxicological parameters as well as its long-term effects.
Are There Medical Benefits to CBD?
In 2017, the National Academies of Sciences, Engineering, and Medicine released a report concluding that cannabis was an effective treatment of chronic pain, chemotherapy-induced nausea and vomiting, and in improving multiple sclerosis spasticity symptoms. The report also found that there was some evidence suggesting that cannabis could be used to treat sleep disorders, excessive weight loss in HIV/AIDS patients, Tourette syndrome, anxiety, and PTSD.
Although the studies reviewed in the report still represent the early phases of cannabis research, current literature suggests that CBD has the potential to treat the following:
Current Psychiatry Reports published a 2017 literature review concluding that while the research on cannabis and sleep is ambivalent, enough evidence suggests that “CBD may hold promise for REM sleep behavior disorder and daytime sleepiness.”
In early 2019, The Permanente Journal released a large retrospective case series on anxiety and sleep finding that CBD may improve anxiety-related symptoms including poor sleep. Researchers administered CBD to 103 adult patients complaining of anxiety or disturbed sleep. Sleep and anxiety scores were evaluated each month for 3 months. At the end of the first month, 66.7 percent of patients experienced improved sleep. However, the scores fluctuated throughout the remainder of the study.
A 2014 study published in the Journal of Clinical Investigation found that CBD regulates the human sebaceous gland, an oil-producing agent implicated in the development of acne, well enough to treat the extremely common skin condition. In addition to reducing oil secretion, CBD exhibited anti-inflammatory effects that seemed to inhibit the development of acne.
The British Journal of Pharmacology published a 2014 study that evaluated CBD’s ability to reduce the progression of breast cancer cells. CBD’s interactions with anti-tumor pathways triggered apoptosis, cell death meant to rid the body of sick cells.
In 2016, Current Oncology released a study examining the effect of CBD on the invasiveness and viability of neuroblastoma (NBL), one of the most common extracranial solid childhood-occurring tumors. The study found that both THC and CBD demonstrated tumor impeding qualities, though CBD was the more active of the two compounds. The study concluded that CBD is “an effective anti-cancer drug in the management of NBL.”
A 2018 study published by Frontiers in Pharmacology found that CBD can inhibit exomes and microvesicles (EMV), structures that have been linked to the onset of cancer. CBD’s inhibition of EMV increases the effectiveness of chemotherapy by sensitizing cancer cells to it. The study found that CBD was effective in reducing EMV in prostate cancer, hepatocellular carcinoma, and breast adenocarcinoma.
The Journal of Pancreatic Cancer released a 2019 literature review that found that THC’s and CBD’s combined interactions with CB1, CB2, and GPR55 can inhibit the growth of tumors. While the review found no clinical studies showing a benefit to pancreatic cancer patients specifically, it concluded that “cannabinoids may be an effective adjunct for the treatment of pancreatic cancer.”
Neurodegenerative and Psychotic Diseases
Surgical Neurology International published a 2018 literature review that examined existing evidence on neurological benefits of phytocannabinoids. The researchers concluded that on its own and in combination with THC, CBD demonstrates neuroprotective qualities that have led patients to use it to treat malignant brain tumors, Parkinson’s disease, Alzheimer’s disease, MS, neuropathic pain, pediatric seizure disorders, and mood disorders.
In 2018, the Schizophrenia Bulletin published a short term (21-day) double-blind, placebo-controlled study examining CBD’s effect on clinical high-risk for psychosis (CHR) patients. The study found that CBD’s modulation of medial temporal and striatal function in CHR patients offers “beneficial effects on anxiety” and “attenuated psychotic symptoms and the distress associated with psychotic symptoms.”
Another 2018 Schizophrenia Bulletin study found that CBD had beneficial effects in schizophrenic patients. The randomized controlled trial evaluated the effect of CBD on 88 patients with schizophrenia. The patients who received CBD seemed to improve in cognitive performance and overall functioning. Additionally, the patients who received CBD were not more likely to experience adverse reactions than those who were given a placebo.
Cannabis is most recognized as a treatment for epilepsy. A 2017 Journal of Epilepsy Research literature review confirmed that CBD has therapeutic potential for epilepsy, though it also concluded that the mechanisms by which CBD inhibits seizures are not well understood and that double-blind, controlled trials are a necessary next step.
In 2017, a Pharmacognosy Research study found that CBD was an effective suppressor of viral hepatitis C (HCV) in vitro, but further studies are needed in vivo (In vitro refers to a medical procedure or experiment performed in a controlled environment like a test tube or lab dish. In vivo refers to a procedure performed on or in a living organism.) Given that there is currently no vaccination for HCV and, if untreated, HCV can lead to liver cirrhosis and cancer, this is a significant finding. CBD has the potential to be a beneficial addition to the current treatments for HCV.
A 2018 Frontiers in Pharmacology study reported the effect of oral cannabidiol on 53 children with autism spectrum disorder (ASD). Overall, the comorbidity problems associated with ASD including self-injury and rage attacks, hyperactivity, sleep problems, and anxiety, were improved by CBD.
Addiction and Anxiety
A 2015 Neurotherapeutics literature review supported the continued exploration of CBD as a therapeutic intervention against addictive drugs, specifically opioids. The evidence reviewed suggested that CBD’s anxiolytic and low addictive-behavior reinforcing properties make it a possible treatment for drug addiction.
The Annual Review of Neuroscience published a literature review in 2016 also finding that the evidence showing CBD’s robust anxiolytic, anti-depressant, and anti-addiction properties make it a promising potential treatment for some psychiatric disorders.