Cannabis

{{silver}}[[File:BCbud.jpg|thumb|right|225px|A bud of [[British Columbia|BC bud]], bud'.]]{{drugs}}
{{cquote|It's good for the [[flu]]
Good for asthma,<BR>
Good for tuberculosis,<BR>
Even…<ref group=note>The last "disease" has been variously reported as "numara thrombosis" or "umara composis", but your guess is as good as anyone's. A live version may have been "glaucomia" {{sic}}.[https://www.youtube.com/watch?v=qwCutF3Vm_k]</ref>|||"Bush Doctor" Peter Tosh, "Legalize It" lyrics (1976)<ref>[https://play.google.com/music/preview/Tvwcarjt3tglsb2h66zd2p6flhy?lyrics=1&utm_source=google&utm_medium=search&utm_campaign=lyrics&pcampaignid=kp-lyrics Legalize It lyrics]</ref>}}

'''Cannabis''' (also commonly known as '''marijuana''', '''weed''', '''pot''', etc.) is a plant (''Cannabis'' spp.) that contains a complex of [[Drug|psychoactive substances]], the most notable of these being tetrahydrocannabinol (usually shortened to THC). The primary species used as drugs are ''C. indica'' and ''C. sativa''. ''C. ruderalis'', which has a low THC content, has been used in some cross-breeding.<ref>''Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible'' by Jorge Cervantes (2006). Van Patten Publishing, 5<sup>th</sup> ed., p. 12. ISBN 9781878823236.</ref>

Cannabis [[woo]] is an umbrella term for various claims regarding the positive effects of cannabis cultivation and use. These generally fall into three basic areas:
#Claims concerning psychoactivity (occasionally extending all the way to [[Terence McKenna|Terence McKenna-esque]] [[New Age|soul-babble]])
#Health claims (often promoted as a [[panacea]],<ref>[http://www.letfreedomgrow.com/cmu/DrTodHMikuriya_list.htm International Classification of Diseases 9 - CM 1996 Chronic Conditions Treated With Cannabis Encountered Between 1990-2004] by Tod H. Mikuriya, 2004 (The American Alliance for Medical Cannabis).</ref> sometimes amounting to a [[quack]] [[cancer]] cure)
#Ecological claims (positive instead of negative predictions from the same scientific illiterates who detest [[GMO]]'s)
[[File:Map of US state cannabis laws.svg|thumb|right|225px|Map showing legal status of cannabis in the United States
{{legend|#196E92|Legal for recreational use}}
{{legend|#55B23A|Legal for medical use}}
{{legend|#C4C9CD|Illegal}} D=Decriminalized]]
In the [[United States]], cannabis currently falls into a legal gray-area: it is illegal at the federal level (see [[War on Drugs]]), but it is legal in 24 states (e.g., [[Colorado]]) as well as [[Guam]], [[Washington, D.C.]], the [[Northern Mariana Islands]], and the [[U.S. Virgin Islands]] and decriminalized in another 7. Medical marijuana is fully legal in 15 other states that don't have legal recreational marijuana, as well as in [[Puerto Rico]]. [[Hemp]]-derived products are federally legal following the passage of the {{wpl|Agriculture Improvement Act of 2018||,}} although states may have their own laws regarding these. So far, the only countries that have legalized recreational use nationwide are [[Uruguay]], [[Canada]], [[South Africa]], [[Georgia (country)|Georgia]] (no, not [[Fun:Georgia|that one]]), Malta, [[Mexico]], [[Thailand]], and Luxembourg. In some other countries, such as the [[Netherlands]], it is not legal but it is tolerated. As of late 2023, Netherlands began a trial with legally licensing domestically-grown cannabis.

Cannabis woo has been associated with other types of woo, such as [[aromatherapy]]<ref>[https://www.leafly.com/news/cannabis-101/terpenes-the-flavors-of-cannabis-aromatherapy Terpenes: The Flavors of Cannabis Aromatherapy] Leafly: The World's Cannabis Resource</ref> and [[chakra]]s.<ref name=PCCchart>[http://berkeleypatientscare.com/wp-content/uploads/2016/04/PCC_PCC7_chart_960px.jpg Patient's Care Collective. The PCC7]</ref>

Cannabis enthusiasts claim a ''startling'' assortment of things that marijuana is just about the best thing ever for, and none of this is because they want to get high as hell, maaaaan.  (Of course, getting high might make you ''feel'' like your problems are solved, or alleviated.) Those who choose not to light up, yet have to contend with the stench and the people who get stoned, may be somewhat less starstruck.

==Health claims==
[[File:1881-01-22-sigaretti-indiani-al-cannabis-indica.jpg|thumb|right|Italian advertisement from 1881: Just breathe the smoke of ''Cannabis indica'' cigarillos to stop the most violent attacks of asthma, nervous cough, colds, extinction of voice, facial neuralgia, insomnia, and to combat all laryngeal coughs and respiratory ailments.]]
Health claims, particularly in the medical marijuana jurisdictions, tend towards the [[dietary supplement]] realm even though marijuana is not covered by the Dietary Supplement Health and Education Act of 1994 (DSHEA) because it is illegal at the federal level. Some health claims even have the [[Quack Miranda Warning]],<ref name=PCCtext>[https://web.archive.org/web/20160424160543/http://berkeleypatientscare.com/2016/04/17/introducing-the-pcc7-system/ Introducing: The PCC7 system] ''Patient's Care Collective'' (archived from April 24, 2016).</ref><ref name=PCCchart/> which was an unintended byproduct of DSHEA.

Let's start with some background on marijuana chemistry. Relevant chemicals in marijuana fall into two broad classes: cannabinoids (which in plants are specific to the ''Cannabis'' genus) and terpenoids (which are widespread in many plants).<ref name=Russo>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165946/ Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects] by Ethan B. Russo (2011) ''Br. J. Pharmacol.'' 163(7): 1344–1364. doi: 10.1111/j.1476-5381.2011.01238.x.</ref><ref name=McPartland>[http://cannabis-med.org/data/pdf/2001-03-04-7.pdf Cannabis and Cannabis Extracts: Greater Than the Sum of Their Parts?] by J.M. McPartland & E.B. Russo (2001) ''J. Cannabis Ther.'' (3/4):103-132.</ref> [[Humans]] and other [[animals]], produce endocannabinoids, which are different than but in the same chemical class as those cannabinoids found in cannabis. The main psychoactive chemical in marijuana is tetrahydrocannabinol (THC). Another important cannabinoid is [[cannabidiol]] (CBD), which is not psychoactive but has many claimed health benefits. Terpenoids in cannabis include ocimene, myrcene, β-caryophyllene, limonene, pinene, myrcene, linalool.

There are two major problems with evaluating medical claims for cannabis:
#There is a large variability of the chemical content of cannabis, particularly since cannabis has been bred for different pharmacological properties. From the medical marijuana supplier perspective, this ranges from plants with high-THC/low-CBD to low-THC/high-CBD, as well as variations in terpenoid content.<ref name=PCCtext/><ref name=PCCchart/> These chemicals may have either synergistic or antagonistic effects with regard to a particular medical treatment, so assessing the effectiveness of medical marijuana as a whole is difficult due to the quantitative chemical variability.
#In general, the quality of [[Evidence-based medicine|medical evidence]] forms a scale, or [[hierarchy of evidence]], ranging from ''in vitro'' cell studies (lowest evidence) to animal bioassays (''in vivo'') to human retrospective studies to human prospective studies to [[meta-analyses]] and [[Review article|reviews]] of all direct evidence. It is difficult and expensive to conduct large-scale, long-term human studies, and the ability of researchers to conduct these has often been hampered by illegality of cannabis. Cannabis advocates may make claims based on ''in vitro'' studies of single chemicals, but this is never convincing evidence for human health&nbsp;— it is merely suggestive for further research.
#"So far, researchers haven't conducted enough large-scale clinical trials that show that the benefits of the marijuana plant (as opposed to its cannabinoid ingredients) outweigh its risks in patients it's meant to treat."<ref name=drugabuse>[https://www.drugabuse.gov/publications/drugfacts/marijuana-medicine Cannabis (Marijuana) Research Report: Is marijuana safe and effective as medicine?] ''National Institute on Drug Abuse''.</ref>

Another problem with research on the medical effects on cannabis is that for the rare cases of US Federal Government-funded research, the cannabis is required to be sourced from the Federal Government.<ref name=ingraham1>[https://www.washingtonpost.com/news/wonk/wp/2017/03/13/government-marijuana-looks-nothing-like-the-real-stuff-see-for-yourself/ Government marijuana looks nothing like the real stuff. See for yourself.] by Christopher Ingraham & Tauhid Chappell (March 13, 2017) ''The Washington Post''.</ref> Such cannabis by today's commercial marijuana standards is considered to be low-grade (ditch weed), and is not comparable in terms of chemical content to what most people actually smoke or ingest.<ref name=ingraham1/>

===Toxicity===
Cannabis and THC are generally considered to have low toxicity, particularly compared to other recreational drugs. One method of assessing toxicity is using the Margin of Exposure (MOE) method, where MOE = Human exposure / Animal [[median lethal dose]]. For example, for [[alcohol]] and [[nicotine]], the MOE is low (<10), meaning the risk is high with the exposure dose close to the lethal dose. For THC, the MOE is high (>10,000), meaning the risk of death is low.<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311234/ Comparative risk assessment of alcohol, tobacco, cannabis and other illicit drugs using the margin of exposure approach] by Dirk W. Lachenmeiera & Jürgen Rehm (2015). ''Scientific Reports'' 5(8126). doi:10.1038/srep08126.</ref>

It has often been claimed (including by former-Presidential candidate [[Gary Johnson]]) that no one has ever died from a marijuana overdose.<ref>[http://www.huffingtonpost.com/2013/09/03/marijuana-deaths_n_3860418.html Here Are All The People Who Have Died From A Marijuana Overdose] by Nick Wing (09/03/2013 03:03 pm ET | Updated Sep 04, 2013) ''Huffington Post''.</ref><ref name=cariz>[http://www.politifact.com/truth-o-meter/statements/2016/aug/16/gary-johnson/gary-johnson-claims-marijuana-cant-kill-and-prescr/ Is it true that marijuana hasn't caused any deaths, while prescription drugs have caused 100,000?] by Joseph Cariz (August 16<sup>th</sup>, 2016 at 4:07 p.m.) ''PolitiFact''.</ref> The first problem with this claim is that it does not clearly state whether the lack of mortality is from direct causes (toxicity), or from indirect causes (i.e., from judgment or psychomotor impairment).<ref name=cariz/>
{{cquote|Too often individuals cite that individuals haven’t died from cannabis&nbsp;— I don't think that's true. It certainly can be argued that cannabis use has contributed to the deaths of individuals, such as due to impairment during driving.|||Dr. Ryan Vandrey, a researcher at Johns Hopkins University who specializes in the behavioral effects of marijuana<ref name=cariz/>}}
Cannabis has been cited as the sole cause of at least some traffic fatalities.<ref name=schipani>[http://www.factcheck.org/2016/08/unpacking-pots-impact-in-colorado/ Unpacking Pot’s Impact in Colorado] by Vanessa Schipani (August 19, 2016) ''FactCheck.org''</ref><ref>[http://www.rmhidta.org/html/2015%20final%20legalization%20of%20marijuana%20in%20colorado%20the%20impact.pdf The Legalization of Marijuana in Colorado:  The Impact. Vol. 3] by Kevin Wong & Chelsey Clarke (2015) Rocky Mountain High Intensity Drug Trafficking Area.</ref> After cannabis legalization in Colorado, traffic fatalities in which cannabis was at least partly-responsible increased to 94 in 2014, a not-insignificant number compared to alcohol-related traffic fatalities for that year (170 fatalities).<ref name=schipani/> Cannabis does impair judgment, motor coordination, and reaction time,<ref name=schipani/><ref>[https://www.drugabuse.gov/publications/research-reports/marijuana/does-marijuana-use-affect-driving Does marijuana use affect driving?] (April 2017) National Institute on Drug Abuse.</ref><ref name=hartman>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3836260/pdf/nihms488287.pdf Cannabis Effects on Driving Skills] by Rebecca L. Hartman & Marilyn A. Huestis (2014) ''Clin. Chem.'' 59(3):1-25.</ref> and its effect on impairment is either additive or synergistic with alcohol.<ref name=hartman/>

Cannabis has been associated with at least 7 cases of heart attacks in different people (at least 4 of whom had normal coronary vasculature) and possibly some deaths, and cannabis is known to have several vascular effects that may be causative (e.g., tachycardia, hypertension, bradycardia, and hypotension).<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2783157/ Cardiac arrest following cannabis use: a case report] by Abdo H Sattout & Mark F Nicol (2009). ''Cases J.'' 2:208. doi:10.1186/1757-1626-2-208.</ref><ref>[https://www.ncbi.nlm.nih.gov/pubmed/11792512 Acute cardiovascular fatalities following cannabis use] by L. Bachs & H. Mørland (2001) ''Forensic Sci. Int.'' 124(2-3):200-3.</ref><ref>[https://www.ncbi.nlm.nih.gov/pubmed/24783463 Is recent cannabis use associated with acute coronary syndromes? An illustrative case series.] by I. Casier et al. (2014) ''Acta Cardiol.'' 69(2):131-6.</ref><ref>[https://www.ncbi.nlm.nih.gov/pubmed/24598271 Sudden unexpected death under acute influence of cannabis] by B. Hartung et al. (2014) ''Forensic Sci. Int.'' 237:e11-3. doi:10.1016/j.forsciint.2014.02.001.</ref><ref>[http://www.snopes.com/cannabis-poisoning-death/ 31-Year-Old British Woman Died of “Cannabis Poisoning”? Although this claim is based on official testimony from a pathologist during an inquiry into a mysterious death, scientific evidence makes such an explanation problematic, if not completely untenable.] by Alex Kasprak (Jul 30<sup>th</sup>, 2017) ''Snopes''.</ref>

===Pain and spasticity===
[[File:Cannabissativadior.jpg|thumb|right|275px|Cannabis depicted in a [[Byzantine Empire|Byzantine]] [[Greek]] manuscript from 512 CE.]]
A 2015 review of human studies in ''The Journal of the American Medical Association'' found that there was high-quality evidence for treatment of chronic [[pain]], neuropathic pain, and spasticity from [[multiple sclerosis]] (MS).<ref name=hill>[http://www.ncbi.nlm.nih.gov/pubmed/26103031 Medical Marijuana for Treatment of Chronic Pain and Other Medical and Psychiatric Problems: A Clinical Review] by K. P. Hill ''JAMA''. 2015 Jun 23-30;313(24):2474-83. doi:10.1001/jama.2015.6199.</ref> The author also concluded that "Medical marijuana is used to treat a host of indications, a few of which have evidence to support treatment with marijuana and many that do not."<ref name=hill/>

A large, multi-faceted literature review by the National Academies of Sciences, Engineering, and Medicine (NASEM) also concluded:<ref name=nas2017>[https://www.nap.edu/catalog/24625/the-health-effects-of-cannabis-and-cannabinoids-the-current-state ''The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research''] by Committee on the Health Effects of Marijuana: An Evidence Review and Research Agenda; Board on Population Health and Public Health Practice; Health and Medicine Division; National Academies of Sciences, Engineering, and Medicine (2017) The National Academies Press. ISBN 9780309453042.</ref>
{{cquote|
*In adults with chronic pain, patients who were treated with cannabis or cannabinoids are more likely to experience a clinically significant reduction in pain symptoms.
*In adults with multiple sclerosis (MS)-related spasticity, short-term use of oral cannabinoids improves patient-reported spasticity symptoms.
}}
The review also concluded that the effects were modest.<ref name=nas2017/> However, separate studies have shown that US states with medical marijuana have reduced opioid prescriptions<ref name=hamers>[https://www.sciencenews.org/article/opioid-epidemic-spurs-search-new-safer-painkillers The opioid epidemic spurs a search for new, safer painkillers: Scientists test alternative drugs that relieve pain without the dangers of opioids] by Laurel Hamers (1:00pm, May 30, 2017) ''Science News''.</ref><ref>[http://content.healthaffairs.org/content/35/7/1230 Medical Marijuana Laws Reduce Prescription Medication Use In Medicare Part D] by Ashley C. Bradford & W. David Bradford (2006) ''Health Aff.'' 35(7):1230-1236. doi:10.1377/hlthaff.2015.1661.</ref> and 25% fewer opioid-related deaths.<ref name=hamers/><ref>[http://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1898878 Medical Cannabis Laws and Opioid Analgesic Overdose Mortality in the United States, 1999-2010] by Marcus A. Bachhuber et al. (2014). ''JAMA Intern. Med.'' 174(10):1668-1673. doi:10.1001/jamainternmed.2014.4005.</ref>

===Nausea===
A 2015 review of [[randomized controlled trial]]s in humans found that the majority of the studies were at risk of [[bias]] due to not being [[double blind]], or from attrition of test subjects. Nonetheless, the authors concluded that marijuana-based medications may be useful for treating nausea.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/26561338 Cannabinoids for nausea and vomiting in adults with cancer receiving chemotherapy] by L. A. Smith et al. Cochrane Database Syst Rev. 2015 Nov 12;(11):CD009464. doi: 10.1002/14651858.CD009464.pub2.</ref> The NASEM report also concluded, "In adults with chemotherapy induced nausea and vomiting, oral cannabinoids are effective antiemetics," and that the effects were modest.<ref name=nas2017/>

===Glaucoma===
Cannabis treatment for intraocular pressure from glaucoma is widely cited as effective, particularly because the first authorized usage of medical marijuana since its criminalization was based on a court case by Robert Randall in 1976.<ref>[http://www.nytimes.com/2001/06/08/us/robert-randall-53-sued-for-marijuana.html Robert Randall, 53; Sued for Marijuana] (June 8, 2001) ''Associated Press'' via ''The New York Times''.</ref> There is some supporting scientific evidence that cannabis is efficacious for at least some types of glaucoma, based on small studies on humans. The effect on intraocular pressure is relatively brief, and there are other pharmaceutical treatments available for glaucoma that have been tested for safety and efficacy.<ref name=sun>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553646/ Marijuana for Glaucoma: A Recipe for Disaster or Treatment?] by Xiaoshen Sun et al. ''Yale J. Biol. Med.'' 2015 Sep; 88(3):265–269.</ref><ref>[http://www.glaucoma.org/treatment/medication-guide.php A Guide to Glaucoma Medications] ''Glaucoma Research Foundation''.</ref> The American Glaucoma Society<ref>[https://www.ncbi.nlm.nih.gov/pubmed/20160576/ American Glaucoma Society position statement: marijuana and the treatment of glaucoma] ''J. Glaucoma.'' 2010 Feb;19(2):75-6. doi:10.1097/IJG.0b013e3181d12e39.</ref> and the Canadian Ophthalmological Society<ref>[https://www.ncbi.nlm.nih.gov/pubmed/20676153/ Canadian Ophthalmological Society policy statement on the medical use of marijuana for glaucoma] ''Can. J. Ophthalmol. 2010 Aug;45(4):324-6. doi:10.3129/i10-069.</ref> oppose medical marijuana usage for glaucoma treatment due to extensive adverse effects.<ref name=sun/>

===Mental health===
The 2017 NASEM review concluded:<ref name=nas2017/>
{{cquote|
* Cannabis use is likely to increase the risk of developing [[schizophrenia]] and other [[Psychosis|psychoses]]; the higher the use the greater the risk.
* In individuals with schizophrenia and other psychoses, a history of cannabis use may be linked to better performance on learning and [[memory]] tasks.
* Cannabis use does not appear to increase the likelihood of developing depression, anxiety, and [[Post-traumatic stress disorder|posttraumatic stress disorder]].
* For individuals diagnosed with bipolar disorders, near daily cannabis use may be linked to greater symptoms of bipolar disorder than non-users.
* Heavy cannabis users are more likely to report thoughts of [[suicide]] than non-users.
* Regular cannabis use is likely to increase the risk for developing social anxiety disorder.
}}
Psychosis is associated with cannabis users who favor high THC/low CBD varieties.<ref name=murray>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5032490/ Traditional marijuana, high‐potency cannabis and synthetic cannabinoids: increasing risk for psychosis] by Robin M. Murray et al. (2016) ''World Psychiatry'' 15(3):195–204. doi:10.1002/wps.20341.</ref> There is also evidence that psychosis is associated with highly-concentrated forms of marijuana (e.g., "dabs", "shatter" and "wax"), as well as with substances with synthetic cannabinoids (a.k.a., "spice").<ref name=murray/> The erroneous idea that dabs are "safe" has been propagated by parts of the cannabis industry without addressing the known risks of consuming high levels of THC.<ref>[https://www.leafly.com/news/cannabis-101/safety-side-effects-of-dabbing Are Dabs Bad for You? Side Effects of Dabbing Cannabis Concentrates] (Published on July 5, 2021; Last updated August 3, 2022) ''Leafly''.</ref><ref name=murray/>

===General===
'''Claim:''' "The combination of THC and terpenes modulates each strain to have its own effect, flavor, energy and medical uses."<ref name=PCCtext/>

'''Research findings''': This is sufficiently [[vague]] that it is basically true,<ref>[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165946/ Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects] by Ethan B. Russo (2011) ''Br. J. Pharmacol.'' 163(7): 1344–1364. doi:10.1111/j.1476-5381.2011.01238.x</ref> but not very informative.

===Cannabinoids===
Because of the evidence above from studies on whole cannabis, the focus below on specific chemicals will be on claims ''other than'' for treatment of pain, nausea, glaucoma, depression and MS. There is reasonable evidence of cannabis efficacy for these claims, though the efficacy regarding a specific chemical may be another matter. Furthermore, the focus below will be on claims regarding specific [[disease]]s (e.g. cancer) or implying the treatment of diseases (e.g., anti-proliferative implies cancer treatment), rather than vague disease-related claims (e.g., antimicrobial).

====Cannabichromene (CBC)====
[[File:Cannabichromene-skeletal.svg|thumb|right|100px|Cannabichromene]]
'''Claims''': treatment of anxiety and stress, anti-viral, cancer, bone growth<ref name=steephill/>

'''Research findings''':
*Anxiety: [[#Mental health|see above]]
*Stress: no studies in PubMed
*Anti-viral: no studies in PubMed
*Cancer: CBC had some effect against breast tumors ''in vitro''.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/16728591 Antitumor activity of plant cannabinoids with emphasis on the effect of cannabidiol on human breast carcinoma] by A. Ligresti et al. ''J. Pharmacol. Exp. Ther.'' 2006 Sep;318(3):1375-87.</ref> The evidence is suggestive for further research.
*Bone growth: no studies in PubMed

====Cannabidiol (CBD)====
{{main|CBD}}
[[File:Cannabidiol.svg|thumb|right|100px|Cannabidiol]]
'''Claims''': treatment of MS, epilepsy, diabetes (by lowering blood sugar), stress, insomnia<ref name=steephill/>

'''Research findings''':
*Diabetes: CBD was effective in lowering the incidence of diabetes in mice in two studies.<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3349875/ The Endocannabinoid System and Plant-Derived Cannabinoids in Diabetes and Diabetic Complications] by Béla Horváth et al. ''Am. J. Pathol.'' 2012 Feb; 180(2): 432–442. doi: 10.1016/j.ajpath.2011.11.003.</ref><ref>[https://www.ncbi.nlm.nih.gov/pubmed/16698671 Cannabidiol lowers incidence of diabetes in non-obese diabetic mice] by L. Weiss et al. ''Autoimmunity'' 2006 Mar;39(2):143-51.</ref><ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1592672/ Neuroprotective and Blood-Retinal Barrier-Preserving Effects of Cannabidiol in Experimental Diabetes] by Azza B. El-Remessy et al. ''Am. J. Pathol.'' 2006 Jan; 168(1): 235–244.</ref> Two studies in humans showed a possible protective effect from  marijuana on diabetes onset ([[Correlation does not imply causation|association but not necessarily causation]]).<ref>[http://www.ncbi.nlm.nih.gov/pubmed/23684393 The impact of marijuana use on glucose, insulin, and insulin resistance among US adults] E. A. Penner et al. ''Am. J. Med. 2013 Jul;126(7):583-9. doi: 10.1016/j.amjmed.2013.03.002.</ref><ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3289985/ Decreased prevalence of diabetes in marijuana users: cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) III] by T. B. Rajavashisth et al. ''BMJ Open'' 2012 Feb 24;2:e000494. doi: 10.1136/bmjopen-2011-000494.</ref>
*Epilepsy: A 2015 review found that purified CBD showed promise in uncontrolled studies, but that [[Experimental control|controlled]] studies were lacking. Questions remain about safety and efficacy.<ref>[https://www.alchimiaweb.com/blogfr/wp-content/uploads/2015/11/Detyniecki-THC-CBD-CNNR-2015-Marijuana-Use-in-Epilepsy-The-Myth-and-the-Reality.pdf Marijuana Use in Epilepsy: The Myth and the Reality] by Kamil Detyniecki & Lawrence Hirsch. ''Curr Neurol. Neurosci. Rep.'' 2015 Oct;15(10):65. doi: 10.1007/s11910-015-0586-5.</ref><ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946683/ Cannabidiol in the Treatment of Epilepsy] by Randi von Wrede et al. (2021) ''Clin. Drug Investig.'' 41(3):211–220. doi:10.1007/s40261-021-01003-y.</ref> A 2017 trial study of 120 patients found that children with a type of childhood epilepsy known as Dravet Syndrome had a greater reduction in convulsions when treated with CBD than [[placebo]].<ref>[http://www.nejm.org/doi/full/10.1056/NEJMoa1611618?query=featured_home& Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome] by Orrin Devinsky et al. (2017). ''N. Engl. J. Med.'' 376:2011-2020. doi:10.1056/NEJMoa1611618.</ref> In 2018, an [[FDA]] panel recommended CBD as the very narrowly defined treatment, specifically for "seizures caused by Lennox-Gastaut syndrome (LGS) and Dravet syndrome in patients aged 2 and older."<ref>[https://www.nbcnews.com/health/health-news/fda-committee-recommends-first-cbd-oil-product-n867511 FDA committee recommends first CBD product: Approval would be the first product actually demonstrated to work] by Maggie Fox (Apr.19.2018 / 10:51 AM ET / Updated 4:37 PM ET) ''NBC News''.</ref>

There is a lot of interest in potential medical uses of CBD, but as of 2024, treatment of Lennox-Gastaut Syndrome and Dravet Syndrome-type epilepsy, and  the only FDA-approved treatment.<ref>[https://www.fda.gov/news-events/public-health-focus/fda-regulation-cannabis-and-cannabis-derived-products-including-cannabidiol-cbd FDA Regulation of Cannabis and Cannabis-Derived Products, Including Cannabidiol (CBD)] ''U.S. Food & Drug Admministration''.</ref><ref>[https://www.sciencenews.org/article/cbd-product-boom-science-research-hemp-marijuana The CBD boom is way ahead of the science: Strict regulations have stunted research on cannabidiol, but that hasn’t hampered product popularity] by Laura Sanders (6:00am, March 27, 2019) ''Science News''.</ref>

====Cannabidiolic Acid (CBD-A)====
[[File:Cannabidiolic acid.png|thumb|right|100px|Cannabidiolic Acid]]
'''Claims''': treatment of inflammation and cancer<ref name=steephill/>

'''Research findings:'''
*Cancer: There are a few ''in vitro'' studies, so the evidence is only suggestive that more research is needed.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/25242400 Down-regulation of cyclooxygenase-2 (COX-2) by cannabidiolic acid in human breast cancer cells] by S. Takeda et al. ''J. Toxicol. Sci.'' 2014;39(5):711-6.</ref>

====Cannabigerol (CBG)====
[[File:Cannabigerol.svg|thumb|right|100px|Cannabigerol]]
'''Claims''': stimulates the growth of new brain and bone cells, antibacterial, anti-tumor (cancer), treatment of insomnia<ref name=steephill/>

'''Research findings''':
*Brain growth: Ordinarily, one does not want to stimulate cell growth because it could increase the risk of cancer. The idea that this is a good thing seems to imply that the claimants (Steephill Labs)<ref name=steephill/> are referring to Huntington's disease, a progressive disease of the brain that causes degeneration of nerve cells.<ref>[http://www.mayoclinic.org/diseases-conditions/huntingtons-disease/basics/definition/con-20030685 Mayo Clinic: Huntington's disease]</ref> A CBG derivative&nbsp;— not CBG itself&nbsp;— was tested in mice with a Huntington's-like disease &mdash; not Huntington's itself, and the results showed promise.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/27430371 VCE-003.2, a novel cannabigerol derivative, enhances neuronal progenitor cell survival and alleviates symptomatology in murine models of Huntington's disease] by J. Díaz-Alonso et al. ''Sci. Rep.'' 2016 Jul 19;6:29789. doi: 10.1038/srep29789.</ref> A different study of CBG itself in mice that did not have any disease also showed some neuroprotection.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/25252936 Neuroprotective properties of cannabigerol in Huntington's disease: studies in R6/2 mice and 3-nitropropionate-lesioned mice] by S. Valdeolivas et al. Neurotherapeutics. 2015 Jan;12(1):185-99. doi: 10.1007/s13311-014-0304-z.</ref> No studies have been conducted on humans, the evidence of CBG being effective on Huntington's is weak.
*Bone growth: no publications on CBG and bone in PubMed between 1966 and 2023
*Cancer: a study of CBG on a mouse model of colon cancer (''in vivo'') showed that CBG hampered tumor progression.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/25269802 Colon carcinogenesis is inhibited by the TRPM8 antagonist cannabigerol, a Cannabis-derived non-psychotropic cannabinoid] by E. Borrelli et al. ''Carcinogenesis''. 2014 Dec;35(12):2787-97. doi: 10.1093/carcin/bgu205.</ref> No studies have been conducted on humans.
*Insomnia: No studies in PubMed

====Cannabinol (CBN)====
[[File:Cannabinol.svg|thumb|right|100px|Cannabinol]]
'''Claims''': treatment of insomnia, nausea and convulsions<ref name=steephill/>

'''Research findings''':
*Insomnia: A 2014 review of cannabinoid administration on [[sleep]] found that there were "various effects of cannabinoid administration on several aspects of sleep", and that because of methodological issues, it was not possible to make a conclusion.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/24726015 The effects of cannabinoid administration on sleep: a systematic review of human studies] by P. J. Gates et al. ''Sleep Med. Rev.'' 2014 Dec;18(6):477-87. doi: 10.1016/j.smrv.2014.02.005.</ref>
*Convulsions: Only 1 reference was found in the US National Library of Medicine PubMed database (between 1966 and 2016) on CBN and convulsions in humans: a single page in an obscure journal.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/3941934 Anticonvulsant effect of cannabidiol] by F. R. Ames & S. Cridland. ''S. Afr. Med. J.'' 1986 Jan 4;69(1):14.</ref> A study on CBD on induced seizures in rats showed that it was an effective anticonvulsant.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/850145 Cannabidiol&mdash;antiepileptic drug comparisons and interactions in experimentally induced seizures in rats] by P. Consroe & A. Wolkin. ''J. Pharmacol. Exp. Ther.'' 1977 Apr;201(1):26-32.</ref> One would have to conclude that the evidence is weak.
*Nausea: {{sl|Nausea|see above}}

====Tetrahydrocannabinol (THC)====
[[File:Delta-9-tetrahydrocannabinol.png|thumb|right|100px|(−)-''trans''-Δ<sup>9</sup>-Tetrahydrocannabinol]]
'''Claims''': "THC has been shown to be effective in the treatment of a variety of ailments and disorders including pain, tumors (cancer), nausea and [[ADHD]]."<ref name=steephill>[http://steephilllab.com/resources/cannabinoid-and-terpenoid-reference-guide/ Steephill Labs: Cannabinoid and terpenoid reference guide]</ref> Kelly Hauf claimed to have cured herself of oligodendroglioma brain cancer by treating herself with cannabis oil.<ref>[http://www.cureyourowncancer.org/ Cure Your Own Cancer]</ref> She now runs a website that reports [[testimonials]], a single case study, and ''in vivo'' studies. The website is also anti-chemotherapy.<ref>[http://www.cureyourowncancer.org/chemo-kills.html Cure Your Own Cancer: Chemo Kills]</ref>

'''Research findings''':
*Cancer: The best evidence of treatment of cancer with marijuana chemicals is suggestive but not convincing, because it relies on ''in vitro'' studies.<ref>[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4470774/ The antitumor activity of plant-derived non-psychoactive cannabinoids] by Sean D. McAllister et al. ''J. Neuroimmune Pharmacol. 2015 Jun; 10(2): 255–267.</ref> A phase 1 clinical trial on a THC-CBD mixture for treatment of brain (and spinal cord) tumours is currently underway.<ref>[http://www.cancerresearchuk.org/about-cancer/cancers-in-general/cancer-questions/is-cannabis-treatment-brain-tumours Is cannabis a treatment for brain tumours?] Cancer Research UK</ref><ref>[http://www.cancerresearchuk.org/about-cancer/find-a-clinical-trial/a-trial-looking-sativex-temozolomide-glioblastoma-multiforme-brain-tumour-gwca1208 A trial looking at Sativex with temozolomide for glioblastoma multiforme brain tumour (GWCA1208)] Cancer Research UK</ref>
*ADHD: In humans, marijuana exposure to the developing embryo and fetus "is associated "with a plethora of neurobehavioural deficiencies…" There is evidence that the deficiencies are due to THC. The deficiencies include anencephaly, ADHD, memory impairment, and learning disability.<ref>[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4147784/ Marijuana, ''Spice'' 'herbal high', and early neural development: implications for rescheduling and legalization] by Delphine Psychoyosa & K. Yaragudri Vinod. ''Drug Test Anal.'' 2013 Jan; 5(1): 27–45. doi:10.1002/dta.1390.</ref>
*Pain: {{sl|Pain|see above}}

===Terpenoids===
====α-Bisabolol====
'''Claims''': anti-inflammatory, anti-irritant, [[antioxidant]], anti-microbial, analgesic<ref name=leafly3>[https://www.leafly.com/news/cannabis-101/myrcene-linalool-and-bisabolol-what-are-the-benefits-of-these-can Myrcene, Linalool, and Bisabolol: What are the Benefits of These Cannabis Terpenes?] Leafly: The World's Cannabis Resource</ref>

====β-Caryophyllene====
[[File:Beta-Caryophyllen.svg|thumb|right|100px|β-Caryophyllene]]
'''Claims''': treatment of sepsis and inflammation, infections (bacterial and fungal), alcoholism, and cancer<ref name=steephill/><ref name=leafly2>[https://www.leafly.com/news/cannabis-101/humulene-caryophyllene-and-trans-nerolidol-what-are-the-benefits Cannabis Terpenes: The Benefits of Humulene, Caryophyllene, and Trans-Nerolidol] Leafly: The World's Cannabis Resource</ref>

====Guaiol====
'''Claims''': antimicrobial, anti-inflammatory<ref name=leafly1/>

====Humulene====
[[File:Humulene.png|thumb|right|100px|Humulene]]
'''Claims''': treatment of cancer, infections (bacterial), inflammation, and appetite suppression<ref name=steephill/><ref name=leafly2/>

'''Research findings:'''
*Cancer: A small, short study of injected tumor cells in mice found some inhibitory effects of α-humulene.<ref>[http://beta.arca.fiocruz.br/bitstream/icict/13250/2/Costa%20EV%20Antitumor....pdf Antitumor Properties of the leaf essential oil of ''Zornia brasiliensis''] by E. V. Costa et al. ''Planta Med.'' 2015 May;81(7):563-7. doi: 10.1055/s-0035-1545842.</ref> Given the shortcomings of this study (injected tumors, small number of animals), the relevance to humans is minimal. ''In vitro'' studies on humulene have also been conducted.

====d-Limonene====
[[File:Limonene rotated.png|thumb|right|100px|d-Limonene]]
'''Claims''': treatment of gastric reflux, antibacterial, antifungal, depression, anxiety, and cancer<ref name=steephill/><ref>[https://www.leafly.com/news/cannabis-101/what-is-limonene-and-what-are-the-benefits-of-this-cannabis-terpe What is Limonene and What are the Benefits of This Cannabis Terpene?] Leafly: The World's Cannabis Resource</ref><ref>[https://www.leafly.com/news/strains-products/best-cannabis-strains-for-depression/ The Best Cannabis Strains for Treating Depression] by Bailey Rahn. Leafly: The World's Cannabis Resource</ref>

'''Research findings:'''
*Gastric reflux: a single, small unpublished study reported positive results in humans.<ref>[http://www.altmedrev.com/publications/16/2/116.pdf Gastroesophageal Reflux Disease (GERD): A Review of Conventional and Alternative Treatments] Lyn Patrick ''Altern. Med. Rev.'' 2011 Jun;16(2):116-33.</ref> This is not convincing evidence because the study was not [[peer-reviewed]] (e.g., the study methods could have been defective, or there could have been [[Experimenter bias|bias]] in the study).
*Cancer: d-limonene was tested in a small phase I trial and a limited phase II for treatment of cancer patients; effectiveness of the treatment was not reported as only tolerance of d-limonene was tested.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/9654110 Phase I and pharmacokinetic study of D-limonene in patients with advanced cancer. Cancer Research Campaign Phase I/II Clinical Trials Committee] by D. M. Vigushin et al. Cancer Chemother Pharmacol. 1998;42(2):111-7.</ref> d-limonene inhibited a liver carcinogenesis mechanism ''in vitro'',<ref name=DeOliveira/><ref name=Russo/><ref name=McPartland/> but this is only suggestive of further research. Furthermore, d-limonene caused kidney tumors in male rats at high doses.<ref>[https://web.archive.org/web/20150910031557/https://toxnet.nlm.nih.gov/cpdb/chempages/D-LIMONENE.html Carcinogenic Potency Project: ''d''-Limonene] (archived from September 10, 2015).</ref><ref>[https://ntp.niehs.nih.gov/ntp/htdocs/lt_rpts/tr347.pdf Toxicology and Carcinogenesis Studies OF ''d''-Limonene (CAS NO. 5989-27-5) in F344/N  Rats AND  B6C3F<sub>1</sub> Mice (Gavage Studies)] National Toxicology Program (1990).</ref>
*Depression and anxiety: [[#Mental health|see above]]

====Linalool====
[[File:Linalool-skeletal.png|thumb|right|100px|Linalool]]
'''Claims''': treatment of insomnia, psychosis, anxiety, epilepsy, depression, and pain<ref name=steephill/><ref name=leafly3/>

'''Research findings''':
*Psychosis: A 2015 review found that marijuana containing high levels of THC was associated with psychosis in users.<ref>[https://www.researchgate.net/publication/270966118_The_adverse_health_effects_of_synthetic_cannabinoids_with_emphasis_on_psychosis-like_effects The adverse health effects of synthetic cannabinoids with emphasis on psychosis-like effects] by Jan GC van Amsterdam et al. Journal of Psychopharmacology 29(3) January 2015 DOI: 10.1177/0269881114565142.</ref> Linalool may or may not counteract the psychotic effects of THC, but it would seem to be wise to avoid marijuana (and THC) as a psychosis treatment.
*Depression and anxiety: [[#Mental health|see above]]
*Pain: [[#Pain|see above]]

====β-Myrcene====
[[File:Myrcene beta straight acsv.svg|thumb|right|100px|β-Myrcene]]
'''Claims''': treatment of cancer, inflammation, pain, insomnia, infection and spasms<ref name=steephill/><ref name=leafly3/>

'''Research findings:'''
*Cancer: β-Myrcene inhibited a liver carcinogenesis mechanism ''in vitro'',<ref name=DeOliveira>[http://www.ncbi.nlm.nih.gov/pubmed/9242356 In vitro inhibition of CYP2B1 monooxygenase by beta-myrcene and other monoterpenoid compounds] by A. C. De Oliveira et al. ''Toxicol. Lett.'' 1997 Jun 16;92(1):39-46.</ref><ref name=Russo/><ref name=McPartland/> but this is only suggestive of further research.
*Pain: [[#Pain|see above]]

====''trans''-Nerolidol====
[[File:Nerolidol trans.svg|thumb|right|100px|''trans''-Nerolidol]]
'''Claims''': inhibits growth of leishmaniasis, antiparasitic, antifungal, antimicrobial<ref name=leafly2/>

'''Research findings:'''
*Leishmaniasis: A mixture of ''cis''- and ''trans''-nerolidol was effective at inhibiting the growth of ''Leishmania'' spp. ''in vitro''.<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1087654/ Antileishmanial activity of the terpene nerolidol] by D. C. Arruda et al. ''Antimicrob. Agents Chemother.'' 2005 May;49(5):1679-87.</ref> The results would only warrant further research.

====Ocimene====
'''Claims''': antiviral, antifungal, antiseptic, decongestant, antibacterial<ref name=leafly1>[https://www.leafly.com/news/cannabis-101/benefits-of-cannabis-terpenes-ocimene-terpinolene-and-guaiol Benefits of Cannabis Terpenes: Ocimene, Terpinolene, and Guaiol] Leafly: The World's Cannabis Resource</ref>

====α-Pinene====
[[File:Alpha-Pinene Isomers.svg|thumb|right|100px|α-Pinene]]
'''Claims''': treatment of asthma and inflammation<ref name=steephill/>

====Terpinolene====
'''Claims''': anticancer, antioxidant, sedative, antibacterial, antifungal<ref name=leafly1/>

==Psychoactive claims==
'''Claim:''' [[God]] gave us cannabinoid receptors so we could smoke pot all day.<ref name=weedmaps>[https://web.archive.org/web/20170819065921/http://boards.cannabis.com/threads/why-marijuana-is-truly-gods-gift-to-heal-the-nations.167494/ Why marijuana is truly God's gift to heal the nations] ''Weedmaps'' (archived from August 19, 2017).</ref> "supertiger" argued, "That's right folks, our brains actually have receptors specifically active to THC. Did God create man with cannabinoid receptors to never use them?" and cited {{bible|Ezekiel|34|29}} and {{bible|Isaiah|18|4|5}}.<ref name=weedmaps/> This is basically an [[appeal to nature]] while asserting that [[Goddidit]].

'''Reality:''' Cannibinoid receptors are activated by {{wpl|endocannabinoids||,}} i.e., cannibinoid chemicals that are naturally produced by the human body (e.g. arachidonoylethanolamine). Activation of cannibinoid receptors causes several physiological functions including gastrointestinal activity, cardiovascular activity and bone growth.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/19103987?dopt=Abstract Activated endocannabinoid system in coronary artery disease and antiinflammatory effects of cannabinoid 1 receptor blockade on macrophages] by Sugamura K. et a. (2009)''Circulation''. 119 (1): 28–36. doi:10.1161/CIRCULATIONAHA.108.811992. PMID 19103987.</ref><ref>[http://www.pnas.org/content/103/3/696.short Peripheral cannabinoid receptor, CB2, regulates bone mass] by Ofek O. et al. (January 2006). ''Proc. Natl. Acad. Sci. U.S.A.'' 103 (3): 696–701. doi:10.1073/pnas.0504187103. PMC 1334629free to read. PMID 16407142</ref>

[[File:Cb1 cb2 structure.png|thumb|center|350px|Human cannabinoid receptors CB<sub>1</sub> and CB<sub>2</sub>]]

So, why then are there cannabinoids in cannabis; did [[Goddidit|God put them there]] because he liked stoners? No. The most likely answer is that wild ''Cannabis'' species with higher levels of THC deter grazing by herbivores. Yes, cannabinoids are one of many<ref>[http://www.jstor.org/stable/2395296 Promising Directions of Study in Tropical Animal-Plant Interactions] Daniel H. Janzen, ''Annals of the Missouri Botanical Garden'' Vol. 64, No. 4, Perspectives in Tropical Botany (1977), pp. 706-736.</ref><ref>[https://web.archive.org/web/20140801180020/https://toxnet.nlm.nih.gov/cpdb/pdfs/PNAS2.pdf Dietary pesticides (99.99% all natural)] by Bruce N. Ames, Margie Profet, and Lois Swirsky Gold (1990)''Proceedings of the National Academy of Sciences USA'' 87: 7777-7781 (archived from August 1, 2014).</ref><ref>[https://web.archive.org/web/20141129024339/https://toxnet.nlm.nih.gov/cpdb/pdfs/Science1992.pdf Rodent carcinogens: Setting priorities] by L. Swirsky Gold, Thomas H. Slone, Bonnie R. Stern, Neela B. Manley, and Bruce N. Ames (1992) ''Science'' 258: 261-265 (archived from November 29, 2014).</ref> natural pesticides produced by plants,<ref>[http://www.druglibrary.net/olsen/HEMP/IHA/jiha4210.html The Drug Library: ''Cannabis'' as repellent and pesticide] by John M. McPartland</ref> just like others&nbsp;— such as [[caffeine]] and capsaicin (the active ingredient in [[Cayenne pepper|chilis]])&nbsp;— that we clever [[ape]]s have found useful and/or enjoyable.

==Ecological claims==
Cannabis has sometimes been [[greenwashing|greenwashed]] as being particularly ecologically sound, either explicitly<ref>[http://www.connexions.org/CxLibrary/Docs/CX5039-MarijuanaEcologicalBenefits.htm The Ecological Benefits of Marijuana] Alan W. Bock</ref> or implicitly (''e.g.'', just by associating it with the color "green"). While this may be true of ditch weed (e.g. uncultivated marijuana with low THC/CBD content) or commercial hemp, it is not very likely for what one is likely to purchase for psychoactive and/or medical purposes. Commercial cannabis is either farmed outdoors (often requiring synthetic pesticides), or indoors (requiring large amounts of electricity for lighting). In California, particularly but not exclusively<ref>[https://www.ocregister.com/2023/04/16/california-is-changing-how-it-goes-after-illegal-cannabis-farms/ California is changing how it goes after illegal cannabis farms: Here's what California counties had the most illegal cannabis plants in 2022] by Kurt Snibbe (April 16, 2023) ''Orange County Register''.</ref> pre-legalization, outdoor marijuana has often been grown illegally on public land, which both deprives the public of access (since it's heavily guarded) and degrades ecosystems with clearing and pollution.<ref>[https://www.hcn.org/blogs/goat/forest-service-video-shows-illegal-marijuana-cultivation-devastating-californias-public-lands Illegal marijuana cultivation is devastating California's public lands] by  Christi Turner (March 6, 2014) ''High Country News''.</ref>

==Risks==
[[File:Bodily effects of cannabis.svg|thumb|right|275px|Bodily effects of cannabis use.]]
For many people, knowing the actual risks of cannabis is difficult. On the one hand, there are those who say it is extremely addictive and causes cancer and mental illness; on the other hand, there are those who say it is not addictive and can remedy cancer and mental illness. To add to the confusion, both camps can quote a large amount of scientific literature supporting their claims. There are two main reasons the scientific evidence behind the risks of cannabis can seem so contradictory: first, prohibition makes studying cannabis' effects tricky for researchers, and second, [[media]] often report studies that have major implications, but not the many subsequent studies that undermine them. For instance, a recent study that reported cannabis use causes an irreversible and large [[IQ]] drop was heavily reported, but the many subsequent studies that failed to replicate its findings were not.<ref name=ingraham2/> This is not just a problem when it comes to cannabis, but all media reporting on science.

It is believed that cannabis is nowhere near as dangerous as [[heroin]] or [[cocaine]], and is also much safer than legal drugs [[alcohol]] and [[tobacco]]. However, there are other illegal drugs, such as [[psilocybin]] and [[LSD]], which are considered safer than cannabis.<ref>[https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(10)61462-6/fulltext Drug harms in the UK: a multicriteria decision analysis] by David J. Nutt et al. (2010) ''Lancet'' 376:1558–65. doi:10.1016/S0140-6736(10)61462-6.</ref>

===Adverse effects===
As previously mentioned, cannabis impairs awareness and thus it is very dangerous to drive or operate machinery while under its influence. And while subjective, the smell can be extremely off-putting.

===Dependence===
Cannabis dependence occurs in about 20% of cannabis users.<ref name=story>[https://www.washingtonpost.com/opinions/2023/12/26/marijuana-addiction-health-problems/ I’m a marijuana enthusiast, but weed is getting a pass on health issues] by Frances Story (December 26, 2023 at 5:45 a.m. EST) ''The Washington Post''.</ref> Cessation by a dependent user causes withdrawal, usually characterized by anxiety, cravings, low mood, and disturbed sleep. These symptoms usually last a couple of days to a week.<ref name=hall>[https://web.archive.org/web/20141018052603/http://onlinelibrary.wiley.com/doi/10.1111/add.12703/full What has research over the past two decades revealed about the adverse health effects of recreational cannabis use?] by Wayne Hall (2015) ''Addiction'' 110(1):19–35. doi:10.1111/add.12703 (archived from October 18, 2014.</ref> Symptoms tend to be mild, comparable to withdrawal symptoms experienced when quitting caffeine. (While this is clearly not a good thing, anyone tempted to cite it as a reason to ban cannabis should compare it to the effects of quitting {{wpl|Nicotine withdrawal|smoking}} or {{wpl|Delirium tremens|alcohol|.}}) A meta-analysis of 21,000 people diagnosed with cannabis use disorder (the medical term for cannabis addiction), found that about 50% of the risk associated with cannabis addiction was [[genetic]], the same genetic links that are associated with risk-taking behavior and nicotine addiction.<ref name=story/><ref name=johnson>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7674631/ A large-scale genome-wide association study meta-analysis of cannabis use disorder] by Emma C. Johnson et al. (2020) ''Lancet Psychiatry'' 7(12):1032–1045. doi:10.1016/S2215-0366(20)30339-4.</ref> Cannabis addiction was also positively [[Correlation does not imply causation|correlated with other mental disorders: ADHD, major depression, and schizophrenia, with no evidence found of a causational effect]].<ref name=johnson/> Also, teenage onset of use is linked to higher levels of dependency (just as with alcohol or nicotine) as well as higher levels of psychiatric disorders.<ref>[https://www.columbiapsychiatry.org/news/recreational-cannabis-use-among-u-s-adolescents-poses-risk-adverse-mental-health-and-life-outcomes Recreational Cannabis Use By Teens Linked to Risk of Depression, Suicidality] (May 5, 2023) ''Columbia University Department of Psychiatry''.</ref><ref>[https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2804450 Nondisordered Cannabis Use Among US Adolescents] by Ryan S. Sultan et al. (2023) ''JAMA Network Open'' 6(5):e2311294. doi:10.1001/jamanetworkopen.2023.11294.</ref>

===Effect on the young===
Cannabis use during [[pregnancy]] "is associated with decreased attention span and behavioral problems." Additionally, [[children]] exposed to cannabis ''in utero'' also are reported to have "lower scores on tests of visual problem solving, visual-motor coordination, and visual analysis" than children who were not exposed.<ref>[https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/10/marijuana-use-during-pregnancy-and-lactation Marijuana Use During Pregnancy and Lactation] Committee Opinion Number 722 (October 2017) ''American College of Obstetricians and Gynecologists''.</ref>

Although a 2012 study purported to find that cannabis use in adolescents leads to a drop in IQ, subsequent studies have found no such effect. But a UK study did find a 3% drop in school exams taken at age 16.<ref name=ingraham2>[https://www.washingtonpost.com/news/wonk/wp/2014/10/22/no-marijuana-use-doesnt-lower-your-iq/ No, marijuana use doesn’t lower your IQ] by Christopher Ingraham (October 22, 2014 at 10:39 a.m. EDT) ''The Washington Post''.</ref>

===Relationship with mental illness===
The link between cannabis use and mental illness is controversial and hotly debated. Cannabis use is associated with anxiety disorders,<ref>[http://www.biomedcentral.com/1471-244X/14/136 A positive association between anxiety disorders and cannabis use or cannabis use disorders in the general population- a meta-analysis of 31 studies] by Karina Karolina Kedzior & Lisa Tabata Laeber (2014) ''BMC Psychiatry 14(136). doi:10.1186/1471-244X-14-136.</ref> but not depressive disorders.<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3796318 Cannabis Use during Adolescent Development: Susceptibility to Psychiatric Illness] by Benjamin Chadwick et al. (2013) ''Front. Psychiatry'' 4(129) doi:10.3389/fpsyt.2013.00129.</ref> [[Correlation does not imply causation]], however, especially when cannabis is so heavily associated with relieving stress. Many sufferers of depression and anxiety who self-medicate with cannabis believe it helps them more than many other remedies.

The relationship between cannabis and psychotic illnesses is more controversial and intricate. It is thought that cannabis with a high concentration of THC (i.e. cannabis that is smoked to get high) worsens pre-existing psychotic illnesses,<ref>[http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0122404 Social Functioning Trajectories of Young First-Episode Psychosis Patients with and without Cannabis Misuse: A 30-Month Follow-Up Study] by César González-Blanch et al. (April 7, 2015) ''PLoS ONE'' doi:10.1371/journal.pone.0122404.</ref> but cannabis with a lower concentration of THC and higher concentration of CBD can help remedy psychosis.<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3797438/ Does Cannabidiol Protect Against Adverse Psychological Effects of THC?] by Raymond J. M. Niesink (2013) ''Front. Psychiatry'' 4:130. doi:10.3389/fpsyt.2013.00130.</ref> It is thought that, for people with a genetic predisposition towards psychotic illness, heavy use of cannabis with a high concentration of THC can "nudge" them into psychosis.<ref>[https://pubmed.ncbi.nlm.nih.gov/26359901/ Proportion of patients in south London with first-episode psychosis attributable to use of high potency cannabis: a case-control study] by Marta Di Forti et al. (2015) ''Lancet Psychiatry'' 2(3):233-238. doi:10.1016/S2215-0366(14)00117-5.</ref>

===Lung damage===
Smoking cannabis can cause bronchitis episodes.<ref>[https://lunginstitute.com/blog/marijuana-use-and-chronic-bronchitis Marijuana Use And Chronic Bronchitis] by Christine Kingsley, ''Lung Institute''.</ref> Sharing water pipes and smoking with multiple people in a confined area ("hotboxing") can contribute to the spread of respiratory disease.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/25401045 Legalizing Cannabis: A physician's primer on the pulmonary effects of marijuana] by Denyse Lutchmansingh (2014) '' Curr. Respir. Care Rep.'' 3(4):200-205.
doi:10.1007/s13665-014-0093-1.</ref>

If medical marijuana is taken by smoking it, this presents the usual problems from a [[science|scientific]] perspective, that is the harm done to the lungs&nbsp;— pot smoke actually contains more "tar" (i.e. aromatic carcinogens like pyrenes) than [[cigarette]]s; while usually less smoke is inhaled, whatever smoke is inhaled is inhaled more deeply than cigarette smoke. Cannabis has not been proven to cause lung cancer,<ref>[http://www.washingtonpost.com/wp-dyn/content/article/2006/05/25/AR2006052501729_pf.html Study Finds No Cancer-Marijuana Connection] by Marc Kaufman (May 26, 2006) ''The Washington Post''.</ref> but bronchitis among other irritations is quite possible. This particular problem can be reduced or avoided by using a vaporizer or putting the marijuana in food or using consumables such as chocolate containing THC. Also, researchers are working on isolating specific active compounds in order to make them deliverable via pill.<ref>[https://www.accessdata.fda.gov/drugsatfda_docs/label/2005/018651s021lbl.pdf Marinol] (Rev Sep 2004) ''U.S. Food & Drug Administration''. In fact, pharmaceutical-grade THC has been sold under the brand name Marinol for a while.</ref>

===Relationship with cancer===
Perhaps the most hotly-debated risk of cannabis use is its effect on cancer. Like many plants, cannabis contains chemicals that in isolation are tumorigenic<ref>[https://web.archive.org/web/20120729115046/http://cancerhelp.cancerresearchuk.org/about-cancer/cancer-questions/does-smoking-cannabis-cause-cancer Does smoking cannabis cause cancer?] ''Cancer Research UK'' (archived from July 29, 2012).</ref> and anti-tumorigenic<ref>[http://www.cancer.gov/about-cancer/treatment/cam/patient/cannabis-pdq/#link/_13 Cannabis and Cannabinoids (PDQ®)–Patient Version: Antitumor activity] ''National Cancer Institute''.</ref> ''in vitro'' (in the lab dish): this is not convincing evidence with regard to human health. For example, both [[aristolochia]] and [[coffee]] contain tumorigenic and anti-tumorigenic chemicals, yet aristolochia is a very potent human carcinogen but coffee improves human health and reduces the risk of some cancers.<ref>[https://monographs.iarc.fr/ENG/Monographs/vol82/mono82.pdf ''Some Traditional Herbal Medicines, Some Mycotoxins, Naphthalene and Styrene.''] IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 82 (2002) World Health Organization, International Agency for Research on Cancer.</ref><ref>[http://www.annualreviews.org/doi/full/10.1146/annurev-nutr-071816-064941 Coffee, Caffeine, and Health Outcomes: An Umbrella Review] by Giuseppe Grosso et al. (2017) ''Annual Review of Nutrition'' 37:131-156.</ref> 

Due at least in part to the illegality of cannabis, there has been a dearth of large-scale, high quality epidemiology studies on cannabis and cancer.<ref name=huang>[http://cebp.aacrjournals.org/content/24/1/15.long An Epidemiologic Review of Marijuana and Cancer: An Update] by Yu-Hui Jenny Huang et al. (2015) ''Cancer Epidemiology, Biomarkers & Prevention'' 24(1):15–31. DOI:10.1158/1055-9965.EPI-14-1026.</ref> A 2015 review of 34 epidemiologic studies found no clear evidence for head and neck cancers, an association with testicular cancer in three relatively small case-control studies, and insufficient evidence for other cancers.<ref name=huang/> It was noted that the majority of the studies were case-control (retrospective) with inherent study weaknesses, and the authors recommended that a large-scale prospective study be conducted.<ref name=huang/> A 2015 large-scale case-control study of cannabis use and bladder cancer that was not reported in the 2015 review found that cannabis was associated with a reduced incidence of bladder cancer, but no cause-and-effect relationship could be established.<ref>[https://www.ncbi.nlm.nih.gov/pubmed/25623697 Association between cannabis use and the risk of bladder cancer: results from the California Men's Health Study] by A. A. Thomas et al. (2015) ''Urology'' 85(2):388-92. DOI:10.1016/j.urology.2014.08.060.</ref>

Harm reduction experts have recommended eating or vaporizing cannabis as a way to avoid or minimize possible carcinogenic chemicals in the smoke.<ref>[https://web.archive.org/web/20151109212035/http://www.drugscience.org.uk/drugs-info/cannabis/ Cannabis / Marijuana] Drugscience (archived from November 9, 2015).</ref>

===Gateway drug hypothesis===
{{main|Gateway drug theory}}

===Flammability===
Regardless of all else, anyone foolish enough to light up in places known to contain large amounts of flammable substances (such as gas stations or in front of racks of propane tanks) is quite literally playing with fire.{{nofact}}

==Medical marijuana==
Medical marijuana<ref name="NIH">[https://nccih.nih.gov/health/marijuana NIH page on medical marijuana]</ref> is the use of [[marijuana]] for medicinal purposes, largely to relieve conditions such as glaucoma,{{efn|Damage to the optic nerve, leading to eye damage and ultimately blindness.}} nausea associated with [[chemotherapy]], and appetite loss in [[AIDS]] patients. It is well-established to relieve chronic pain<ref name="pain">[http://www.ncbi.nlm.nih.gov/pubmed/26103031 Medical Marijuana for Treatment of Chronic Pain & Other Medical and Psychiatric Problems: A Clinical Review] by Kevin P. Hill (2015) ''JAMA'' 313(24):2474-2483. doi:10.1001/jama.2015.6199.</ref> without the intense physical dependency that comes with opiates or other CNS depressants. Cannabis has also been shown to assist in management of many gastrointestinal disorders, including Crohn's disease, irritable bowel disorder, and more.<ref name="jama">[http://www.ncbi.nlm.nih.gov/pubmed/26103030 Cannabinoids for Medical Use: A Systematic Review and Meta-analysis] by Penny F. Whiting et al. (2015) ''JAMA'' 313(24):2456-2473. doi:10.1001/jama.2015.6358.</ref>

The issue is a hotly contested one (in the [[United States]]) because many states have specifically legalized this use of cannabis, while the federal government continues to insist on classifying cannabis as a dangerous "narcotic" with no medical value ("Schedule I"), and criminally prosecuting those who grow, sell, and use the plant.

===Pros===
[[File:MMPU tidy.jpg|thumb|right|165px|Stoned, but tidy.]]
A common argument in favour of medical marijuana is a [[moral]] one: that the government should not be dictating what an informed person can and cannot put into their own body, and should not be treating those who choose to use one substance or another as criminals. However, see [[health freedom]]; depending on who is making the argument, this argument is sometimes the edge of a [[slippery slope]].

While cannabis has many of alternative medicine's [[anecdotal evidence]] for symptomatic relief (just ask any pothead about the munchies, regarding use as an appetite stimulant), its effectiveness has also been proven in numerous controlled studies.<ref name="jama"/><ref>[http://www.ncbi.nlm.nih.gov/pubmed/24614667 Cannabis (medical marijuana) treatment for motor and non-motor symptoms of Parkinson disease: an open-label observational study] (Clin Neuropharmacol. 2014 Mar-Apr;37(2):41-4. doi: 10.1097/WNF.0000000000000016.)</ref><ref>[http://www.ncbi.nlm.nih.gov/pubmed/24854149 The case for medical marijuana in epilepsy] (Epilepsia. 2014 Jun;55(6):783-6. doi: 10.1111/epi.12610. Epub 2014 May 22)</ref><ref>[http://www.ncbi.nlm.nih.gov/pubmed/25427150 Medical marijuana in neurology] by Itay Lotan (2014) ''Expert Rev. Neurother.'' 14(12):1453-65. doi:10.1586/14737175.2014.985209.</ref> This even includes the aforementioned munchies.<ref name="appetite">[http://www.ncbi.nlm.nih.gov/pubmed/22133305 A pilot study of the effects of cannabis on appetite hormones in HIV-infected adult men] by Patricia K. Riggs et al. (2012) ''Brain Res.'' 1431:46-52. doi:10.1016/j.brainres.2011.11.001.</ref>

While cannabis use is not without risk, it is far less dangerous as a medical painkiller than opioids.<ref>[https://www.frontiersin.org/articles/10.3389/fpsyt.2020.592199/full Ranking the Harm of Psychoactive Drugs Including Prescription Analgesics to Users and Others&nbsp;– A Perspective of German Addiction Medicine Experts] by Udo Bonnet et al. (2020) ''Front. Psychiatry'' 11:592199. doi:10.3389/fpsyt.2020.592199.</ref>

In terms of the substances' abilities to cause dependence, the numbers seem superficially similar&nbsp;— about 9% of ''all'' marijuana users, medical or recreational, become addicted<ref name=hall/> and about 10% of those ''prescribed medical opioids'' become addicted to them.<ref>[https://pubmed.ncbi.nlm.nih.gov/25785523/ Rates of opioid misuse, abuse, and addiction in chronic pain: a systematic review and data synthesis] by Kevin E. Vowles (2015) ''Pain'' 156(4):569-576. doi:10.1097/01.j.pain.0000460357.01998.f1.</ref> However, the cannabis data is heavily weighted towards recreational users, who are self-selected for substance dependence by the fact that they are using the substance without a legitimate medical need, and also by the fact that in recreational use, cannabis is often mixed with highly addictive drugs like tobacco or alcohol. In comparison, about 80% of heroin addicts have previously been prescribed opioid painkillers,<ref>[[https://www.pnas.org/content/117/4/1917 Predicting high-risk opioid prescriptions before they are given] by Justine S. Hastings et al. (2020) ''PNAS'' 117(4):1917-1923. doi:10.1073/pnas.1905355117.</ref> with most of the remaining 20% being the family members of those prescribed medical opioids, showing the potential for opioid addictions to escalate.

In terms of potential lethality to the patient, the effective dose for an opioid to elinate one's pain is only about a tenth of the dose that would eliminate one's pain with cannabis, painkilling effects are experienced at less than a 10000<sup>th</sup> of the lethal overdose (though smaller overdoses can definitely make one [[Paranoia|think that one is dying]]). Doctors in US states with medical marijuana write fewer prescriptions for opioid painkillers.<ref name=hamers>[https://www.sciencenews.org/article/opioid-epidemic-spurs-search-new-safer-painkillers The opioid epidemic spurs a search for new, safer painkillers: Scientists test alternative drugs that relieve pain without the dangers of opioids] by Laurel Hamers (1:00pm, May 30, 2017) ''Science News''.</ref><ref>[https://www.healthaffairs.org/doi/10.1377/hlthaff.2015.1661 Medical Marijuana Laws Reduce Prescription Medication Use In Medicare Part D] by Ashley C. Bradford & W. David Bradford (2006) ''Health Aff.'' 35(7):1230-1236. doi:10.1377/hlthaff.2015.1661.</ref> In a later separate study, it was found that states with medical marijuana had a 25% lower rate of opioid overdose mortality, and that states with recently implemented medical marijuana laws had decreased opioid mortality over time.<ref name=hamers/><ref>[http://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1898878 Medical Cannabis Laws and Opioid Analgesic Overdose Mortality in the United States, 1999-2010] by Marcus A. Bachhuber et al. (2014). ''JAMA Intern. Med.'' 174(10):1668-1673. doi:10.1001/jamainternmed.2014.4005.</ref>

Policing of cannabis offences results in disproportionate abuse and incarceration of Black and other minority communities<ref>[[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2561263/ The Race/Ethnicity Disparity In Misdemeanor Marijuana Arrests In New York City] by Andrew Golub et al. (2007) ''Criminol. Public Policy'' 6(1):131–164. doi:10.1111/j.1745-9133.2007.00426.x</ref>&nbsp;— even the initial illegality of the drug was driven by [[racism]], rather than by any objective medical harms.<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7173675/ Racism and Its Effect on Cannabis Research] by Robert Solomon (2020) ''Cannabis Cannabinoid Res.'' 5(1): 2-5. doi:10.1089/can.2019.0063.</ref> Unfortunately, it does not necessarily follow that allowing medical use of cannabis will do anything to stop the [[War on Drugs]]&nbsp;— while US states where cannabis is legal have varying policies on it,<ref>[https://www.rollingstone.com/feature/cannabis-legalization-states-map-831885/ The United States of Weed: Curious about the status of cannabis? Here’s where legalization stands, state by state] by Ryan Bort et al. (April 18, 2023) ''Rolling Stone''.</ref> cannabis arrests often still continue, and those profiting from medical marijuana are disproportionately wealthy and white. Some Black activists are sceptical of legalisation for this reason, viewing it as a means to take money out of the pockets of largely poor, Black drug dealers and into the pockets of 27-year-old Harvard grads named Colby. However, many others support it, as a means to end mass incarceration and racism, often along with other policies such as forgiveness of those imprisoned for cannabis offences and social equity programs in the medical marijuana industry. Some of the more recent states to legalize, such as [[New York]] and [[Connecticut]], have tried to address these issues with their legalization bills by including measures that assist minority communities that were the most affected by the War on Drugs as well as expunging prior marijuana convictions.<ref>[https://mugglehead.com/new-york-legalizes-americas-most-progressive-recreational-weed-market/ New York legalizes US’s most progressive recreational weed market: Records will be expunged, 50% of licences will go to equity applicants and corporate cannabis will be limited under a bill signed Wednesday by Gov. Cuomo] by  Jared Gnam (31 March 2021) ''Mugglehead Magazine''.</ref><ref>[https://www.jdsupra.com/legalnews/recreational-cannabis-is-legal-in-6591224/ Recreational Cannabis is Legal in Connecticut: What to Know About Getting into the Business] by Andrew Glassman (9 July 2021) ''JDSUPRA''.</ref>

For autistic persons, medical cannabis has demonstrated an improved quality of life for its users.<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9887656 Silva, Estácio Amaro da Junior et al. “Cannabis and cannabinoid use in autism spectrum disorder: a systematic review.” Trends in psychiatry and psychotherapy vol. 44 e20200149. 13 Jun. 2022, doi:10.47626/2237-6089-2020-0149]</ref>

===Cons===
Medical marijuana is sometimes also associated with [[alternative medicine]] and the use of herbs for medicinal purposes. In this case, there is the lack of a controlled, carefully measured dose of the plant's active compounds,{{efn|Not just THC, but CBD, CBN and who knows what else.}} which can vary widely from plant ot plant.

The issue has implications for those of us who believe much (not necessarily all) of alternative medicine is [[quackery]] and [[woo]].  Believing that, for example, [[laetrile]] is ineffective [[bullshit]] does not necessarily mean believing that it should be illegal or that people should be prosecuted for using or selling it in the United States as they currently are. The same goes even more so for medical marijuana, which unlike laetrile ''does'' have some scientific studies showing it is effective for treating some specific conditions.<ref name="jama"/>

There are potential adverse effects from cannabis, which can be mitigated:
*Cannabis can be {{sl|Toxicity|toxic}}: it has rarely caused death directly, but it can indirectly cause death from cognitive impairment while driving a vehicle.
*Cannabis can cause a variety of {{sl|Mental health|mental disorders}}.
*Teenage use of cannabis increases the likelihood of {{sl|Dependence|cannabis use disorder}} as well as psychiatric disorders.
*{{sl|Effect on the young|Fetal exposure to cannabis from the mother}} can later reduce the child's visual-motor coordination and visual analysis capabilities.
Mitigations include:
*Not being under the influence of cannabis while driving or using heavy machinery
*Avoiding the use of high THC/low CBD varieties of cannabis, and not using concentrates
*Waiting until after teenage years before using cannabis
*Not using cannabis while pregnant

==See also==
*[[Bill Maher]] 
*[[Ethiopian Zion Coptic Church]]
*[[Hemp]]
*[[Fun:Sir Paul McCartney|Macca]]
*[[Rastafari]]
*[[War on Drugs]], including the [[War on Drugs#Pothead pseudohistory|Pothead pseudohistory]] section
*[[Gateway drug theory]]

==External links==
*[http://www.youtube.com/watch?v=Ye3ecDYxOkg "Toking" with Lawrence Welk], Welk thinks "One Toke Over the Line" is a "modern spiritual."
*[https://www.youtube.com/watch?v=Azf320JDdqU ''Reefer Madness''!]
*[http://vaporblog.org/blog/marijuana-vaporizers-overview/ 'Cannabis Vaporization FAQ']
*[https://examine.com/supplements/marijuana/ Examine.com: Marijuana] &mdash; an independent review of the medical effects of marijuana
*[http://www.nationalmssociety.org/Treating-MS/Complementary-Alternative-Medicines/Marijuana National Multiple Sclerosis Society: Medical Marijuana (Cannabis)] &mdash; includes guideline from American Academy of Neurology on medical marijuana
* {{wpa|Legality of cannabis}}
* {{wpa|Legality of cannabis by U.S. jurisdiction}}

==Notes==
{{reflist|group=note}}

==References==   
{{reflist|2|80%}}

[[Category:Drugs]]
[[Category:Herbal medicine]]
[[Category:Media hysteria]]
[[Category:Plants]]

Categories: Drugs, Herbal medicine, Media hysteria, Plants