Potency

[1]. In 2018 Michigan legalized the use of marijuana for adults. Since this law took effect, increased availability and use of cannabis have led to an increase in emergency department (ED) visits, as well as complaints about the drug's neuropsychiatric effects [2]. High doses of cannabis can be associated with undesired effects such as paranoia, psychotic-like symptoms, and panic attacks, depending on the content of its principal active constituent, D9-tetrahydrocannabinol (THC), and that of cannabidiol, a constituent with anti-anxiolytic properties [3]. Higher concentrations of THC relative to cannabidiol, as demonstrated in many commercial products, are associated with increased incidence of psychotomimetic symptoms [4,5]. Various studies in adults with acute THC exposure have shown a dose-related reduction in performance at laboratory tasks measuring memory, divided and sustained attention or concentration, reaction time, and tracking and motor function [3,6-9]. Less is known regarding the acute effects of THC in the pediatric population, and much of the

data that currently exist involve retrospective reviews of large, coded data sets [10-12]. The purpose of this study was to describe the prevalence, clinical features, and disposition of cannabis neuropsychiatric toxicity in a community-based study.

 All cannabis‐based and cannabinoid medications should be subjected to the  rigorous scrutiny of the Federal Food and Drug Administration (FDA) regulatory process.  This process provides important protections for patients, making medications available  only when they: 1) are standardized by identity, purity, potency and quality; 2) are accompanied by adequate directions for use in the approved medical indication; and 3)  have risk/benefit profiles that have been defined in well‐controlled clinical trials. 

Detailed Information
. Patients freely share their “medicine” with family and friends, and parents are self-diagnosing, and subsequently dosing their children with high-concentration marijuana products for conditions that may simply not exist (attention-deficit/hyperactivity disorder, anxiety, etc.); or allow their medical cards to expire and continue to grow their own.
The use of marijuana for medical conditions, including pain, needs robust studies, and subsequent products need more regulation and consistency for public consumption. Colorado is an example of the societal effect across a wide spectrum of arenas that comes with rampant cannabis use, particularly in youth use and impaired driving fatalities. The problems Colorado is seeing completely transcend “responsible use” or “marijuana as medicine.” 

PowerPoint Presentation comparing Marijuana & Alcohol,

Pot is becoming more potent, a new study suggests.
In the study, the researchers looked at more than 38,600 samples of illegal marijuana seized by the U.S. Drug Enforcement Administration over 20 years. They found that the level of THC, or tetrahydrocannabinol— marijuana's main psychoactive ingredient — in the marijuana samples rose from about 4 percent in 1995 to about 12 percent in 2014.
Conversely, the level of CBD, or cannabidiol — an ingredient sometimes touted for its potential health benefits — fell from about 0.28 percent in 2001 to less than 0.15 percent in 2014.
But smoking marijuana with high doses of THC may involve a higher risk of negative health effects, such as psychosis orpanic attacks, he said.
"Great article- clearly based on the previous posted comments  marijuana severely impairs a person's ability to understand and process information. Their anecdotal evidence continues to validate scientific statistics. " -No2Pot

See report for details, graphs, data.

The majority of the products we tested were inaccurately labeled," said study author Ryan Vandrey, of The Johns Hopkins University School of Medicine in Baltimore.

Marijuana contains more than 400 chemicals. The primary psychoactive chemical is delta-9- tetrahydrocannabinol (THC) and is the component of marijuana principally responsible for the “high” experienced by pot smokers. Along with the high, users exhibit slower reflexes and decreased coordination. Marijuana also impairs judgment. Slower reaction times, impaired judgment, and problems responding to signals and sounds equal dangerous drivers. No wonder those who drive within three hours of smoking marijuana are twice as likely to be involved in a major car crash.

State of the Science   190 resources
Several problems are associated with marijuana use during pregnancy, because prenatal exposure influences brain development and can result in permanent cognitive impairment. [35] Cognitive deficits resulting from prenatal exposure include inattention; impulsivity; and impairment in learning, memory, and certain aspects of executive functioning. [36] In addition, prenatal exposure to cannabis has been associated with reduction of fetal growth. [37]
For many years, the myth of smoked cannabis being "healthier" or "no worse" than smoked tobacco was perpetuated by pro­marijuana groups. Both smoked cannabis and tobacco contain approximately 4000 chemicals and that these chemicals are essentially identical in both plants.In another recent review, [23] the authors concluded that "smoking of cannabis is not medically recommended due to the potential respiratory tract, dangers of noxious compounds such as polycyclic aromatic hydrocarbons, tar and carbon monoxide."
 
 

The fact is that there is no level of THC in blood above which everyone is impaired, and below which no one is impaired.  This is not because we need more studies; it’s because of human biology. Consider the following three factors.

Marijuana today is "genetically modified," with THC levels that "far surpass the marijuana" of the 1970s.    YES

The number of samples confiscated with a THC concentration greater than 9 percent has increased significantly, from 3.2 percent in 1993 to 21.5 percent of the 1,635 marijuana samples collected in 2007.

There is absolutely no reliable scientific evidence that THC is necessary to synergize the effects of CBD. Instead, there is evidence from preclinical research that THC may be pro-convulsant in sensitive brains; other research indicates that chronic use of THC can impair IQ in adolescents. Physicians are beginning to report instances of THC toxicity in children taking “high CBD” preparations, e.g., high anxiety, increased seizures, insomnia, etc. Until more is known, the most conservative course of action would be to remove THC entirely from a CBD product.