A prospective cohort survey study of 292 IBD patients examining the use of cannabis in IBD found that patients who reported using it for relief of symptoms associated with IBD (16%) reported using it to treat abdominal pain (90%), nausea and poor appetite (73% each), and diarrhea (42%)Reference 1226. The majority (61%) of cannabis-using patients in this survey reported smoking cannabis. Most cannabis-using patients also reported cannabis as being "very helpful" or "completely relieving" in treating the symptoms patients sought to relieve. Current cannabis users were younger than non-users, had lower SIBDQ scores, and were more likely to have chronic abdominal pain.
Hemp is more abundant in CBD, and generally contains only 0.3 percent THC or less. CBD oils, which are processed from the hemp plant, are legal to possess under federal law as long as they contain no more than 0.3 percent THC. Unlike marijuana, CBD doesn’t seem to have addictive qualities, according to the World Health Organization.
A 2014 review article in the New England Journal of Medicine summarized what is known about the effects of marijuana on all aspects of health. The authors found that marijuana use has been associated with vascular conditions that increase the risk of heart attack and stroke, although the mechanisms by which that happens aren’t clear.
Key limitations across these studies are the associative nature of the findings meaning that causality cannot be established, and the inability to determine if cannabis actually replaced or substituted for opioid use, as users potentially could have accessed and used opioids from other non-medical sources. In Canada, nabiximols (Sativex®) is approved (with conditions) as an adjunctive analgesic in adults with advanced cancer who experience moderate to severe pain during the highest tolerated dose of strong opioid therapy for persistent background painReference 431. Current dosing recommendations for nabiximols suggest a maximum daily dose of 12 sprays (32.4 mg THC and 30 mg CBD) over a 24 h periodReference 122Reference 138Reference 431, although higher numbers of sprays/day have been used or documented in clinical studiesReference 284Reference 431.
The weight of the evidence suggests the association between cannabis exposure and schizophrenia is modest but consistentReference 183. Furthermore, the bulk of the literature suggests that individuals with a family history of schizophrenia, individuals with prodromal symptoms, and individuals who have experienced discreet episodes of psychosis related to cannabis should be strongly discouraged from using (THC-predominant) cannabis and psychoactive cannabinoidsReference 183. The influence of cannabis use on age at onset of both schizophrenia and bipolar disorder (with psychotic symptoms) has been studied using regression analysisReference 186. The authors of this study found that although cannabis and other substance use was more frequent in patients with schizophrenia than those diagnosed with bipolar disorder, cannabis use was nonetheless associated with a younger age at onset of both disorders.
Both depression and PTSD have been associated with reduced levels of circulating endocannabinoidsReference 167Reference 1010. CB1 receptors are expressed on various peripheral tissues including the heart and vasculature, and CB receptor agonists and endocannabinoids decrease arterial blood pressure and cardiac contractility (reviewed inReference 1008).
In one study, it was concluded that smoking of cannabis is associated with significant airway inflammation which was similar to what encountered in tobacco smokers . Cannabis inhalation causes increased prevalence of chronic cough/chronic bronchitis, wheezing and shortness of breath with increased clinic visits for acute respiratory illnesses .
Evidence from observational studies suggests that cannabis use could help alleviate opioid withdrawal symptoms, but there is insufficient clinical evidence from which to draw any reliable conclusions. Pre-clinical and human experimental studies suggest a role for certain cannabinoids in alleviating post-traumatic stress disorder (PTSD)-like symptoms. Human experimental data suggests cannabis and THC have a dose-dependent effect on sleep-low doses appear to decrease sleep onset latency and increase slow-wave sleep and total sleep time, while high doses appear to cause sleep disturbances. Evidence from pre-clinical studies suggests that CBD best CBD gummies exhibits anxiolytic effects in various animal models of anxiety, while limited evidence from clinical studies suggest CBD may have anxiolytic effects in an experimental model of social anxiety.
THCV at a dose of 10 mg/kg (i.p.) and CBDV at a dose of 200 mg/kg (i.p.) have been shown to reduce acute nausea in rats, potentially through a CB1 receptor-independent mechanism, but nothing is known about their ability to suppress anticipatory nauseaReference 626. A subsequent study examined the effects of combining CBD and THC, and CBDA and THC on acute nausea and vomitingReference 117. The study showed that 2.5 mg/kg CBD (i.p.), when combined with 1 mg/kg THC (i.p.), resulted in significant suppression of acute nausea and vomiting in an animal model and similarly, when 0.05 mg/kg (i.p.) CBDA was combined with 1 mg/kg THC, acute nausea and vomiting were significantly suppressed. Singular administration of either 2.5 mg/kg CBD, 1 mg/kg THC, or 0.05 mg/kg (i.p.) CBDA was not associated with any suppression of acute nausea and vomiting.
Prenatal cannabis use has been associated with lower scores on language, memory and abstract/visual reasoning domains in children of preschool ageReference 1381Reference 1503-Reference 1505. In school-aged children, prenatal cannabis exposure was also associated with deficits in attention and presence of impulsivity and hyperactivityReference 1381Reference 1506-Reference 1508. A study conducted in pregnant mice using a low dose of THC has been shown to alter the expression level of 35 proteins in the fetal cerebrumReference 62.