youth

Both high- and low-frequency marijuana usage were associated with a significantly increased risk of schizophrenia. The frequency of use among high- and low-frequency users is similar in both, demonstrating statistically significant increased risk in developing schizophrenia.

A new study finds that approximately one in three adolescents were exposed to marijuana promotions on social media or had a favorite marijuana brand.
 
Those who did had five times higher odds of past-year marijuana use.
 
Researchers recommend future studies might want to find ways to restrict marijuana marketing to young people.

Conclusions: Marijuana use varied in association with beliefs about its beneficial and harmful health properties. Clinical interventions that target specific marijuana-related health beliefs including unfounded claims of benefit may provide robust talking points for centering provider guidance and public health messaging.

We found that among young recreational cannabis users, a regular dose of cannabis had no effect on simple and learned tasks, but its use led to significant impairments on complex and novel driving-related tasks, as well as perceived driving ability and safety, for up to 5 hours after use. The present finding that the first 5 hours after cannabis use affected driving-related performance substantiates the recommendations of Canada’s Lower-Risk Cannabis Use Guidelines, which recommend waiting 6 hours after cannabis use before driving.30
 

From 2005 to 2015, 4,202 marijuana-related visits were identified. Behavioral health evaluation was obtained for 2,813 (67%); a psychiatric diagnosis was made for the majority (71%) of these visits. Coingestants were common; the most common was ethanol (12%). Marijuana-related visits increased from 1.8 per 1,000 visits in 2009 to 4.9 in 2015. (p = < .0001) CONCLUSIONS: Despite national survey data suggesting no appreciable difference in adolescent marijuana use, our data demonstrate a significant increase in adolescent marijuana-associated emergency department and urgent cares visits in Colorado.

"More than anything, what we have done is provided good, solid evidence that there is a direct link between marijuana policies and education," lead author Andrew Plunk, PhD, from Eastern Virginia Medical School, Norfolk,

Analysis indicated that for each year adolescent boys engaged in regular marijuana use, their projected level of subsequent subclinical psychotic symptoms increased by 21% and projected risk for subclinical paranoia or hallucinations increased by 133% and 92%, respectively.

With youth usage and perception of harm having significantly  increased the past 4 it would be better to compare data to 10 years ago not last year.

A new study suggests marijuana smokers may be significantly more likely to develop an addiction to other drugs and alcohol than people who don’t use marijuana.
The study, published in JAMA Psychiatry, included almost 35,000 adults who were interviewed three years apart. At the time of the first interview, almost 1,300 used marijuana. After three years, two-thirds of people who used marijuana had some form of substance use disorder, compared with less than 20 percent of people who did not use marijuana in the previous year.

Is legal 'medical' marijuana linked to high youth substance abuse rates?

Let's look at Colorado's substance abuse rates in 2011- 2012 when medical marijuana was legal but recreational pot was not, Colorado youth ages 12- 17 and 18- 25 ranked in the top percentiles for most substance abuse rates: illicit drugs, marijuana, cocaine, non-medical use of painkillers and ranked the lowest for perception of great risk of smoking marijuana.

Pharmacokinetic and pharmacodynamic investigations are also required. Finally, the health consequences of passive vaping should be also considered.  
In conclusion, the new social phenomenon of vaping may slide from nicotine towards other psychoactive drugs (e.g., THC); it therefore deserves the urgent scientific investigation and strict risk assessments which are especially important when young people are concerned. In particular, the presence of toxic substances in the cannabis aerosols generated by e-cigs—from multiple models, brands, BHO and e-liquid manufacturers—need to be investigated.
A synthesis of the practical recipes and experiments reported on the Internet (in addition to our own experiments) shows that the simple, direct use of purified cannabis extracts in e-cigs is not easy because cannabinoids are poorly soluble in e-liquids. Indeed, used pure or in mixture with glycerol, the propylene glycol (PG, or propane-1,2-diol) that is commonly used in e-liquids has both hygroscopic and hydrophilic properties. Consequently, it is not miscible with mineral and vegetable oils and fats. In contrast, cannabinoid concentrates are very lipid soluble, but water insoluble. Furthermore, PG, glycerol, terpenoids, plant fats and waxes, cannabinoid concentrates and THC are very viscous substances. Accordingly, the manufacture of a homogeneous solution using these viscous liquids is a tedious task. Cannabinoid concentrates resemble more a thick, sticky, gummy resin than a liquid. We can infer from these facts that they do not mix readily with glycols, and even less so with glycerol. The addition of terpenoids (e.g., limonene) or lecithin has been advocated to help make cannabis oils miscible...

Given these statistics.... is legalization worth the consequences....
Cannabis has been found to be the most frequently used drug in the U.S. after alcohol, tobacco and caffeine. 
The risk of developing addiction associated with cannabis use has been reported to increase to about 17% among those who start using marijuana in adolescence, and to 25-50% among those who smoke marijuana daily.
The long-term effects of marijuana use include altered brain development and cognitive impairment, including impaired neural connectivity in specific brain regions, decreased activity in prefrontal regions, and reduced volumes in the hippocampus.
Cannabis is most commonly consumed through smoking, a route of drug delivery that predictably has a variety of negative effects on pulmonary function. Smoke from marijuana combustion has been shown to contain a number of carcinogens and cocarcinogens, as well as many of the toxins, irritants, and carcinogens as tobacco smoke.  Additionally, marijuana smokers tend to inhale more deeply and hold their breath longer than cigarette smokers, which leads to a greater exposure per breath to “tar” (the carcinogenic solids in smoke). Regular smoking of marijuana, in the absence of tobacco, produces visible and microscopic injury to the large airways
http://www.asam.org/docs/default-source/publicy-policy-statements/mariju...

This week, the Department of Health and Human Services found that marijuana use among all Americans 12 and over – especially those over 26 – significantly increased in 2014 compared to 2013. The number of 16 and 17 year-olds using marijuana in the past month also increased, (14.2% versus 15.0%).

About 27% of high school students who have used both marijuana and e-cigarettes reported using the devices to vaporize cannabis. Those most likely to vaporize pot with e-cigarettes included males and younger students.

In summary, marijuana use is harmful to children and adolescents.  For this reason, the American College of Pediatricians opposes its legalization for recreational use and urges extreme caution in legalizing it for medicinal use.  Likewise, the American Academy of Child and Adolescent Psychiatry (AACAP) recently offered their own policy statement opposing efforts to legalize marijuana. They similarly pointed out that “marijuana’s deleterious effects on adolescent brain development, cognition, and social functioning may have immediate and long-term implications, including increased risk of motor vehicle accidents, sexual victimization, academic failure, lasting decline in intelligence measures, psychopathology, addiction, and psychosocial and occupational impairment.” 

Over the next few hours, the man showed erratic speech and hostile behaviors, the report said. About 2.5 hours after he ate the whole cookie, he jumped off a balcony on the fourth floor of his building, and died from trauma from the fall, the report said.

Seeing advertisements for medical marijuana was related to middle school adolescents' intentions to use marijuana and their actual marijuana use one year later. Researchers say this is particularly important given that the mean age of adolescents surveyed was 13 and initiation of marijuana use during early adolescence is associated with poor school performance, neuropsychological performance deficits and further use of other illicit drugs, such as heroin and cocaine.

The U.S. Drug Enforcement Agency, in their 2013 National Drug Threat Assessment Summary, noted,“Transnational Criminal Organizations (TCO) and criminal groups will increasingly exploit the opportunities for marijuana cultivation and trafficking created in states that allow ‘medical marijuana’ grows and have legalized marijuana sales and possession.“ Meaning that marijuana legalization may well increase criminal gang activity.

Boys who smoke marijuana go through puberty earlier but grow more slowly than those who have never smoked the drug according to a study presented today at the European Congress of Endocrinology in Dublin, Ireland. The findings will lead to a better understanding of the dangers of drug abuse on growth and development of children.

Participants in a study who had used the drug daily for around three years in their teens had an abnormally shaped hippocampus by the time they were in their early 20s.
They also performed around 18 per cent worse in long-term memory tests than individuals who had never touched the drug.

The study is among the first to say the hippocampus is shaped differently in heavy marijuana smokers and the different looking shape is directly related to poor long-term memory performance.
The study also found that young adults with schizophrenia who abused cannabis as teens performed about 26 percent more poorly on memory tests than young adults with schizophrenia who never abused cannabis.

·        These consequences include impaired short-term memory and decreased concentration, attention span, and problem solving, which clearly interfere with learning. Alterations in motor control, coordination, judgment, reaction time, and tracking ability have also been documented; these may contribute to unintentional deaths and injuries among adolescents (especially those associated with motor vehicles if adolescents drive while intoxicated by marijuana).
·        Negative health effects on lung function associated with smoking marijuana have also been documented, and studies linking marijuana use with higher rates of psychosis in patients with a predisposition to schizophrenia have recently been published, raising concerns about longer-term psychiatric effects. New research has also demonstrated that the adolescent brain, particularly the prefrontal cortex areas controlling judgment and decision-making, is not fully developed until the mid-20s, raising questions about how any substance use may affect the developing brain. Research has shown that the younger an adolescent begins using drugs, including marijuana, the more likely it is that drug dependence or addiction will develop in adulthood.
·         A recent analysis of 4 large epidemiologic trials found that marijuana use during adolescence is associated with reductions in the odds of high school completion and degree attainment and increases in the use of other illicit drugs and suicide attempts in a dose-dependent fashion that suggests that marijuana use is causative.

Dr Marwaha said: "The observed tendency for cannabis use to precede or coincide with rather than follow mania symptoms, and the more specific association between cannabis use and new onset manic symptoms, suggests potential causal influences from cannabis use to the development of mania. It is a significant link."

Where do the students get their marijuana? 38% reported they got from a friend who obtains it legally, 23% reported from their parents, 22% from the black market, 9% from medical marijuana dispensaries, 4% from medical marijuana cardholders, 3% from retail marijuana stores.

Appendix

Changes in Marijuana Use Patterns, Systematic Literature Review, and Possible Marijuana-Related Health Effects

In 2012 and afterwards California 12th graders as compared to their peers in other states became (a) 25% more likely to have used marijuana in the past 30 days, (b) 20% less likely to perceive regular marijuana use as a great health risk, (c) 20% less likely to strongly disapprove of regular marijuana use, and (d) about 60% more likely to expect to be using marijuana five years in the future. Analysis of 10th graders raises the possibility that the findings among 12th graders may reflect a cohort effect that was set into place two years earlier.

“It’s a natural plant! What’s the big deal?” —A common declaration among youth who believe that the effects of marijuana are harmless and that the substance shouldn’t be regulated.  Regardless of public opinion, the science is clear:  Regular recreational use of marijuana during adolescence is harmful to the brain, which isn’t fully developed until the age of 25.

• Most Marijuana Use Begins in Adolescence: 78% of the 2.4 million people who began using in the last year were aged 12 to 20.
• As perception of harm decreases, teen marijuana use increases.
• Every Day, 3,287 Teens Use Marijuana for the First Time

Teenagers who start smoking cannabis daily before the age of 17 are seven times more likely to commit suicide, a study has found.

The emerging marijuana industry in Colorado is trying to appeal to teenagers by offering cannabis-infused soda, chocolate taffy and jujubes.

States that legalized medical marijuana had higher rates of marijuana use. Future research needs to examine whether the association is causal, or is due to an underlying common cause, such as community norms supportive of the legalization of medical marijuana and of marijuana use.

In this review, we will provide a detailed overview of studies outlining the effects of regular (at least weekly) cannabis use on neurocognition, including studies outlining cognitive, structural and functional findings. We will also explore the public health impact of this research.

"Our results suggest that adolescents are particularly vulnerable to develop cognitive impairment from cannabis and that the drug, far from being harmless, as many teens and even adults are coming to believe, can have severe neurotoxic effects on the adolescent brain,"..

As expected, prescription cannabinoids are effective antiemetics and appetite stimulants, and some studies report their effectiveness as adjunct therapy in chronic pain syndromes, spasticity, and glaucoma. Similar results are reported by the few studies of smoked cannabis plant for these same indications. As noted earlier, safe and effective alternative treatments for all these syndromes are available.  Studies assessing psychological aspects of smoked cannabis and prescription cannabinoids uniformly report undesired effects: acute psychosis, poorer prognosis of chronic psychosis, or cognitive dulling in medical patients.