Potency

Cannabis potency has risen significantly over the past several decades, with available evidence pointing to an increased risk of Cannabis use disorder, psychosis, acute cognitive impairment, and structural brain changes with use of high-potency Cannabis. Clinicians should consider asking patients who use marijuana about potency to better assess risk of psychiatric adverse effects.

Marijuana is typically four-times stronger than it was a couple decades ago. On top of the boosted potency, since legalization, growers have been able to refine their skills to grow strains for unique and specific ailments. Not to mention the exploding market of concentrates and dab culture.

The simple fact that THC is fat soluble. That makes it absorbed in a very different way and much more difficult to relate behavior to, say, [blood] levels of THC or develop a breathalyzer."  The height of your intoxication isn't at the moment when blood THC levels peak, and the high doesn't rise and fall uniformly based on how much THC leaves and enters your bodily fluids, says Marilyn Huestis, who headed the chemistry and drug metabolism section at the National Institute on Drug Abuse.

"We found that frequent use of high-potency cannabis significantly affects the structure of white matter fibres in the brain, whether you have psychosis or not," 
The main psychoactive ingredient in weed, tetrahydrocannabinol (THC), is much more concentrated in modern skunk strains as compared to traditional pot and hash -- up 14 percent as compared to 4 percent.

Marijuana use by kids between the ages of 12 and 17 is 58 percent higher in Colorado than the national average, according to the RHMIDTA. The rate of use among college-age adults is 54 percent above the national average. Drug-related suspensions from Colorado schools jumped 34 percent from the 2005-2009 period to the 2010-2014 period, while alcohol-related suspensions stayed flat.
 "Everything they said would happen has not," says Gorman. "They said alcohol use would go down. Alcohol use went up. They said it would eliminate the (marijuana) black market. We are the black market. The trends show that legalization is not working."
 

The proliferation of foods infused or coated with THC has become a growing concern, even among some marijuana advocates. Several high-profile marijuana crimes and deaths involve consumption of edible THC products.
“When THC is available in food, it’s even harder for people to see it as a drug,” Lewis said. “But it is a drug. It is a depressant, a hallucinogen and an addictive substance that changes chemistry in the brain. Research shows all of the above.”

In old-school dope, levels of THC — the psychoactive chemical that makes people high — were typically well below 10 percent. But in Colorado's legal bud, the average THC level is 18.7 percent, and some retail pot contains 30 percent THC or more, according to research released Monday.
"This shows that marijuana is a GMO product just like other products sold by big business. And just like other industries, now you have a big marijuana industry determined to hide these findings from the public. Where is their outcry? Where are the promises to change the way they do business?" 

Based upon the foregoing evidence, this author has a clear preference for zero tolerance laws to deal with the increasing scourge of DUID.  The increasingly accepted Libertarian view is that such laws criminalize personal choices that cause no harm to citizens other than the drug consumer.  Laws requiring probable cause be first established before requiring a blood sample theoretically alleviate this concern, but are unconvincing to opponents of zero-tolerance laws.  Adoption of New Zealand’s approach is suggested as a means of gaining acceptance of zero tolerance laws without unduly harming Libertarian sensitivities.

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

The paper points out that the potency of marijuana has increased fourfold since the 1980s and can hardly be compared to the less harmful drug millions of pot smokers used decades ago.
And opponents point to Colorado and Washington, where the passage of medical marijuana in 2000 and 1998, respectively, were followed by the passage of recreational marijuana laws in 2012.

We welcomed in a new industry that knowingly promotes an addictive and harmful substance SO THAT PEOPLE COULD MAKE MONEY. The business of business is to make money and when there is money to be made people will signup no matter how messed up the means are. 
For these businesses to continue making the huge money they are making they will need to do two things: 1) engage new users, 2) convert current users to more frequent users.
Our weed in Colorado is so strong (20-30 percent THC in its smoked form) that we have a strain called “green crack.”
Our concentrates, which are advertised aggressively, are 80-90 percent THC, and are often smoked on a super-heated needle and puts the smoker on their back with one hit.  Our edibles come in gummies, fruit sodas, suckers, candy and yummy looking baked goods that are so potent that a single pot brownie in Colorado comes with a warning that it has to be cut into fourths before consuming.