The Dangers for Teens of Legalizing Marijuana/Medical Marijuana

By Alexandra Thurstone G’80, ’84, Head of School

If there is ever one of my newsletter articles that you read, I really hope it is this one.  This is an extremely important topic and I want our parents to have the same information that the school has.  

I don’t make a habit of preaching to the St. Francis community on politically sensitive topics.  However, this is one about which I feel so strongly that I am compelled to share my opinion and some facts with you.  There are various points of view on this issue – benefits to legalizing marijuana for medical use; our country spends too much time and money prosecuting and incarcerating people for crimes related to marijuana; marijuana just isn’t that bad for us; and so on.

However, as seen in Colorado, relaxing marijuana laws has had a devastating effect on teens, and this is my major concern.  

In March 2012, we brought my brother-in-law, Dr. Chris Thurstone, to the School to talk to parents and students, and this year in October 2015, he came back to talk to us again.  Chris is one of the leading national/international experts on why legalizing marijuana even for medical use is bad for teenagers.  Chris is an adolescent psychiatrist, addictionologist and the medical director of Colorado’s largest youth substance abuse clinic, as well as an associate professor of psychiatry at the University of Colorado Denver.  He was trained at the University of Chicago and Northwestern University, and he also completed a five-year National Institutes of Health certificate in research methodology on teen substance abuse.  The clinic that Chris directs is in Denver, where marijuana is now legal and where there are actually more marijuana outlets than Starbucks outlets.  As the prevalence of medical marijuana (MMJ) grew in Denver, Chris started to see more patients in his adolescent substance abuse clinic, most of whom were there for marijuana addiction, which caused him to look into the correlation.  All of this information is thanks to his research on the subject.

A quick background on the history of legal marijuana in Colorado:  Marijuana was first legalized for medical use in Colorado by a state amendment in 2000, after six years of lobbying.  From 2000-08, there were 2,000 patients on the medical marijuana registry, meaning a doctor had recommended marijuana for them to treat an illness – it is indicated to relieve the symptoms of about eight very severe conditions.  In 2008 and 2009, a couple of things changed, including the fact that the federal government stated that it would not pursue individuals for prosecution in states with MMJ laws; this touched off an explosion in MMJ outlets, as well as the number of patients on the registry, which rose to 110,000 by September 2011.  Some other interesting facts about those on the registry as of 2012 were:

  • that they are 68% male
  • their average age is 41
  • 98% are taking marijuana for “severe pain,” the most loosely defined of the conditions for which MMJ is indicated.
  • 12 doctors in Colorado made 75% of the recommendations; five doctors made 50% of them; most of those doctors have restricted medical licenses

Concurrent with the explosion of MMJ outlets and patients on the marijuana registry, teen marijuana use also started to rise, as seen through some alarming statistics:

  • In 2008, there was a nine-year low of 3,700 drug-related disciplinary actions in public schools, but then in 2010-11, Colorado K-12 schools saw a 10-year high of 5,417 drug-related disciplinary actions, and this was not a blip, as the number was 5,249 in 2013-14.
  • In 2008-09, there were 534 expulsions from Colorado schools, followed by a 40% increase in 2009-10 to 753, which was sustained in 2010-11 at 767.
  • While “marijuana use in the past month” by 12- to 17-year-olds has held relatively steady nationwide from 2006 to 2014, rising to 7.1% from 6.7%, in Colorado it has risen to 11.2% from 7.6%.  Past-month marijuana use by 18- to 24-year-olds has had a similar trend: it rose to 19% from 16% nationwide, whereas it rose to 30% from 21%  in Colorado
  • Even more alarming is the fact that 49% of teens in a substance abuse program in Denver in 2012 reported receiving their marijuana from someone with an MMJ license and 79% reported using someone else’s MMJ
  • 67% of adolescent substance abuse hospital admissions nationally are for marijuana use; however, a whopping 95% of patients at Denver Health and Hospital Authority admitted for substance abuse are there for marijuana abuse

MarijuanaThoughts2015The other alarming factor in the legalization of marijuana in Colorado is the explosion of edibles and the clear evidence of who is being targeted with these products.  There are 827 retail stores, 1,145 marijuana cultivation facilities, and 261 edible producers in Denver – the opportunities to consume marijuana are prevalent, to say the least. Take a look at this article on the Partnership for Drug Free Kids website and at the picture below that shows just a few of the edible marijuana products being sold.  In addition to the fact that the packaging clearly targets a younger demographic, Chris told us that one of the biggest challenges with the edible products is dosing: for example, a serving may be half a gummy bear, but who eats half a gummy bear, and who is reading the package to determine what a serving is?  In addition, not surprisingly, there are many cases of children eating these products not knowing what they are consuming.   

All of this is alarming; however, the research Chris presented on why marijuana (MJ) in general is so harmful to teens today, and worse than it was back in OUR day, is even more alarming.  Many of you may have heard some of this information, but in case not, please take a look at what is now considered fact:

  • We probably all know that the brain is not fully developed in adolescence and therefore that it is more susceptible to the problems with drug use and addiction
  • Today’s MJ is more potent and more addictive than the MJ most adults experienced in their youth: for decades the THC content in MJ was about 2.3%; today it exceeds 8%, and often reaches 35% in Medical MJ
  • MJ is physically and psychologically addictive for adolescents – 17% of teens (one in six) who try MJ before the age of 18 develop abuse/dependency (vs. 9% for adults)
  • It is now proven that MJ use in adolescence primes the brain for other addictions – teen MJ users are two to three times more likely to use other illicit substances.  In other words, MJ is in fact a gateway drug.
  • MJ use also affects cognition: decreases verbal fluency, word recall, visual scanning ability, visual scanning reaction time, whole brain volume and overall percentage of cortical matter
  • MJ use predicts lower educational attainment: teens who use MJ are 3.6 times less likely to get a high school degree, 2.3 times less likely to enroll in college, and 3.7 times less likely to get a college degree
  • Most scary of all:  Heavy MJ exposure starting in adolescence predicts an eight-point drop in IQ from age 13 to 38 years

Chris also told us that there are three primary factors that affect teen marijuana use, all of which have been impacted by the rise of MMJ.

  • Availability:  in addition to the fact that there are more MMJ outlets than Starbucks stores in Denver, 56 are within 1,000 feet of a school; 370 of the 1,692 public schools are within a mile of an MMJ outlet (22%);
  • Perceived Harmfulness: students surveyed in 2010 reported that they believed occasional/regular marijuana use was less harmful than students in the same survey in 2009;
  • Social Norms: there has been a decrease in students who disapprove of peers’ marijuana use.

All of this presents a rather sobering picture for teens who use marijuana (excuse the pun!).  But what can we do about this? First of all, it’s important that we all have the facts, and that we can share and reinforce them with our children.  We need to be a part of ensuring that our children know that marijuana is indeed harmful to them and that it is most definitely not the norm to use it.  In addition, we can let our state representatives know that legalizing marijuana for medical use is bad for teenagers and a bad idea for Kentucky – such bills have been presented in the Kentucky legislature for several years now.  We must demand that the evidence from Colorado be thoroughly examined before we would consider taking such a step. You can learn more at , which is a bipartisan organization made up of mental and public health professionals and others committed to spreading the truth about marijuana and promoting the idea that there is a better solution between “incarceration and legalization”.

If you have any questions or would like to talk further about this information, please call me at 736-1016 or email me.  In addition, there are two websites that Chris referenced in his talks that you can go to for more information:  is the National Institute on Drug Abuse’s website, which has a teen and parent section.  And the most up-to-date info on marijuana was written by Chris and the Colorado Department of Education at; this includes an info sheet, a brochure, and slides to download.  For anyone concerned about your own children, Chris also recently published a book called Clearing the Haze: Helping Families Deal with Teen Addiction by Christian Thurstone and Christine Tatum (his wife, a journalist), which is available on Amazon at  Please also check out Chris’s website at