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CBD is readily obtainable in most parts of the United States, though its exact legal status is in flux. All 50 states have laws legalizing CBD with varying degrees of restriction, and while the federal government still considers CBD in the same class as marijuana, it doesn’t habitually enforce against it. In December 2015, the FDA eased the regulatory requirements to allow researchers to conduct CBD trials. Currently, many people obtain CBD online without a medical cannabis license. The government’s position on CBD is confusing, and depends in part on whether the CBD comes from hemp or marijuana. The legality of CBD is expected to change, as there is currently bipartisan consensus in Congress to make the hemp crop legal which would, for all intents and purposes, make CBD difficult to prohibit.
Cannabidiol (CBD) has been recently covered in the media, and you may have even seen it as an add-in booster to your post-workout smoothie or morning coffee. What exactly is CBD? Why is it suddenly so popular?
The bottom line on cannabidiol
CBD is commonly used to address anxiety, and for patients who suffer through the misery of insomnia, studies suggest that CBD may help with both falling asleep and staying asleep.
CBD may offer an option for treating different types of chronic pain. A study from the European Journal of Pain showed, using an animal model, CBD applied on the skin could help lower pain and inflammation due to arthritis. Another study demonstrated the mechanism by which CBD inhibits inflammatory and neuropathic pain, two of the most difficult types of chronic pain to treat. More study in humans is needed in this area to substantiate the claims of CBD proponents about pain control.
CBD has been touted for a wide variety of health issues, but the strongest scientific evidence is for its effectiveness in treating some of the cruelest childhood epilepsy syndromes, such as Dravet syndrome and Lennox-Gastaut syndrome (LGS), which typically don’t respond to antiseizure medications. In numerous studies, CBD was able to reduce the number of seizures, and, in some cases, it was able to stop them altogether. Videos of the effects of CBD on these children and their seizures are readily available on the Internet for viewing, and they are quite striking. Recently the FDA approved the first ever cannabis-derived medicine for these conditions, Epidiolex, which contains CBD.
CBD stands for cannabidiol. It is the second most prevalent of the active ingredients of cannabis (marijuana). While CBD is an essential component of medical marijuana, it is derived directly from the hemp plant, which is a cousin of the marijuana plant. While CBD is a component of marijuana (one of hundreds), by itself it does not cause a "high." According to a report from the World Health Organization, "In humans, CBD exhibits no effects indicative of any abuse or dependence potential…. To date, there is no evidence of public health related problems associated with the use of pure CBD."
A categorization of the included studies in accordance with Oxford Centre for Evidence-Based Medicine – Levels of Evidence criteria is presented in Table 3. Among “Healthy Volunteers,” both studies, Pacifici et al.  and Pacifici et al., were at the same level of evidence: 2b. Both studies are prospective cohorts without homogeneity with a longitudinal approach. Among “Marijuana Users,” the only study, Sexton et al.  is classified as 3b. It is a case-control study with a small sample size performed on cross-sectional design. Among “Volunteers with Multiple Sclerosis,” Katona et al.  and Killestein et al.  are classified as 1b. That because the studies are an RCT performed with a homogeneous population with a longitudinal approach.
Responding to potential aggressions, the immune system activates the innate and adaptive immunities by producing inflammatory cytokines, which mediate and potentiate the inflammatory process  that, in turn, signals an alteration of homeostasis. Although the immune system in normal conditions addresses potential aggressions and pathogen antigens, several dysfunctions turn the system to recognize the autoantigens as an aggressor and cause autoimmune diseases. Detailed information about immune cytokines, interleukins, and inflammatory cell function is presented in Table 1.
Flowchart about review numbers.
MS is an autoimmune inflammatory disease with several physical and mental symptoms, which affects deeply the patient’s quality of life [30-33]. These MS-associated symptoms can be treated by current drug therapies that cause considerable side effects, including hallucinations, hypotension, seizures, anxiety, weakness, and nausea . According to Goodin et al. , the effectiveness of the disease-modifying therapeutics agents in reducing disability progression in relapsing-remitting MS patients is unclear. The articles analyzed in this study, on the contrary, reveal that cannabis extracts and cannabinoids promote improvement in MS symptoms and seemed to have little impact on the serum inflammatory markers’ levels [26, 27], which suggests that improvements may occur through different mechanisms involving the cannabinoids. Considering that immune diseases, such as MS, systemic lupus erythematosus, and rheumatoid arthritis are considerably disabling both physically and mentally, the potential of decrease in the immune function caused by cannabis extracts and cannabinoids could provide a pathway through which inflammatory diseases could be addressed by reducing disease immune activity.
Reviewed studies until March 2019 of marijuana use and inflammatory markers
Data were independently extracted by the first author (M.G.L.) using a structured form and reviewed by the senior author (T.M.F.). The following variables were extracted: (1) author’s name, (2) year of publication, (3) country where the study was conducted, (4) sample size, (5) sample characteristics, (6) study design, (7) age range of the sample, (8) statistical analysis performed, (9) instrument(s) utilized, (10) exposure covariates, (11) outcome measures, (12) major findings, and (13) study limitations. Discrepancies were resolved by consensus, and a third author (E.B.) was consulted when needed. Data concerning cannabis use and its relationship with inflammatory markers were described, when available. It was not possible to describe or standardize cannabinoid consumption for all papers reviewed because many of them did not mention smoke patterns and also because articles applied very heterogeneous measurement methods. Publication including only cannabidiol or synthetic cannabinoids was not included.
The correlation between immune response and cannabis use has been explored, as in the longitudinal study performed by Kagen et al. , which aimed to evaluate the role of cannabis use on inducing sensitization to Aspergillus. It was important to find that cannabis users had a higher risk of fungal exposure and infection, increasing the variety of immunologic lung disorders presented by the subjects. Roth et al.  performed a study aiming to analyze the production of nitric oxide (NO) on cannabis users and the role of NO as an antimicrobial agent. The study provides the role of cannabis use decreasing NO production, which acts as an important mediator of antibacterial effects. So, these studies illustrate direct and indirect impact of cannabis use on the susceptibility to infections.