The effects of cannabis are caused by chemical compounds in the cannabis plant, including 113 different cannabinoids such as tetrahydrocannabinol (THC) and 120 terpenes, which allow its drug to have various psychological and physiological effects on the human body. Different plants of the genus Cannabis contain different and often unpredictable concentrations of THC and other cannabinoids and hundreds of other molecules that have a pharmacological effect, so that the final net effect cannot reliably be foreseen. Acute effects while under the influence can sometimes include euphoria. Although some assert that cannabidiol (CBD), another cannabinoid found in cannabis in varying amounts, may alleviate the adverse effects of THC that some users experience, little is known about CBD effects on humans. Cannabinoid receptor antagonists have previously been tested as antidotes for cannabis intoxication with success, reducing or eliminating the physiological and psychological effects of intoxication. Some of these products are currently in development as cannabis antidotes. In the United States, medical cannabis research is limited by federal restrictions. Smoking any substance could possibly carry similar risks as smoking tobacco due to carcinogens in all smoke, and the ultimate conclusions on these factors are disputed.Cannabis use disorder is defined as a medical diagnosis in the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Chemistry
Cannabinoids and cannabinoid receptors
The most prevalent psychoactive substances in cannabis are cannabinoids, particularly THC. Some varieties, having undergone careful selection and growing techniques, can yield as much as 34% THC.
A 2012 systematic review found although it was difficult to draw firm conclusions, there was some evidence that prenatal exposure to cannabis was associated with "deficits in language, attention, areas of cognitive performance, and delinquent behavior in adolescence". A report prepared for the Australian National Council on Drugs concluded cannabis and other cannabinoids are contraindicated in pregnancy as it may interact with the endocannabinoid system. Effects in pediatrics
Children can become exposed to cannabis, typically through accidental exposure which can lead to very high doses, especially in the case of edibles. Unlike in adults, these levels of exposure can lead to major complications in children. These complications include encephalopathy, hypotension, respiratory depression severe enough to require ventilation, somnolence, coma, and there have been case reports of death. Pediatric exposure to edibles is of increasing concern because these products are typically sweets (gummies, cookies, etc. ), and their prevalence is increasing as cannabis is legalized or decriminalized in many territories. See also
Cannabis smoking
Psychoactive drug

References
Further reading
National Academies of Sciences, Engineering, and Medicine (2017). The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research. National Academies of Sciences, Engineering, and Medicine. Washington, DC: The National Academies Press. doi:10.17226/24625. ISBN 978-0-309-45304-2. PMID 28182367. {{cite book}}:  CS1 maint: multiple names: authors list (link)