So today I was thinking about marijuana, and the difficulty some parents may be having in light of recent movements toward legalization across the country. Connecticut began legalizing marijuana for medical use in 2012. Alaska, Colorado, Oregon, and Washington have legalized it for recreational use. We encourage all parents to talk with their teens about the dangers of substance abuse, but the landscape and context of these discussions is changing rapidly, especially when it comes to marijuana. We may have unintentionally created something of a “gray” area. As parents and doctors, it is worth thinking about, because I guarantee the kids are thinking about it.

First, we need to say that “decriminalization” and “legalization” are a long way from “healthy” and “advisable”.  It may be that marijuana is not as bad for us as was sometimes thought, and it may be that other illegal drugs of abuse are far more dangerous. I have heard many patients tell me that it is no worse than tobacco or alcohol.  I am not so sure of that judgement, but it is surely faint praise. We spend an awful lot of time telling patients of all ages how unhealthy tobacco is, regardless of the form in which it is consumed. And alcohol, whatever its possible virtue in moderation, can be extremely dangerous when used by teenagers. So, we should go a bit carefully here.

Another distinction to keep in mind with marijuana is the important differences between adults and teenagers with still-developing brains.  While there is some evidence that moderate MJ use in adults may have a safety profile comparable to tobacco, teenagers differ from adults in a number of ways. Important parts of the human brain, particularly those related to self-control and judgement, are not fully developed until the early 20’s for most people, and it is likely that mind-altering chemicals will behave differently in this still-developing tissue.  One recent study, for example, showed a persistent loss of IQ, 8 points on average, for young smokers, that did not improve later when they stopped smoking.  Another study demonstrated actual changes in the size and shape of certain structures within the brain (like the amygdala and nucleus accumbens) following even light MJ use.  These areas are associated with changes in motivation, attention, memory, and processing emotion. Such changes are not seen in patients who begin smoking after their mid-20’s.

The recent re-classification of marijuana as “medicine” can may also create the impression of a broadly beneficial drug, but it is worth keeping in mind how narrow those demonstrated benefits really are.  There is modest evidence that cannabinoids (the active ingredients in pot) can be useful in managing nausea associated with chemotherapy, spasticity resulting from multiple sclerosis, and increasing the appetite of AIDS patients.  In Connecticut, it has also been approved for use in epilepsy, Parkinson’s, Crohn’s disease, and PTSD, although it is known to worsen many psychiatric conditions.  Still, this is a pretty narrow list of fairly sick people where a reasonable argument might be made that the benefits outweigh potential harms.  Even so, we have limited data on dosing amounts, frequency, and forms.  When I studied pharmacology, I remember the professor starting with the general guidance that “Drugs are poison” to foster a healthy respect for the probability of side effects and the limitations of our knowledge.  There is a degree of truth in that for all medications, whether made in a lab or grown in the earth, and it certainly holds true here as well.

A few additional quick tidbits: One meta-analysis (a compilation of numerous studies) showed that marijuana use doubled the risk of car accidents, a particular concern with young drivers. While the drug’s “high” is usually measured in hours, its effects on higher cognitive function (think school-work) can linger for days. Contrary to common belief, it can indeed be addictive, especially when use begins in adolescence. And keep in mind, the marijuana being sold today is far more potent than that which was used or studied in generations past.

Hopefully, some parents will find this information relevant and useful. It is a complicated topic, and I have only touched the surface here.  Many will have different perspectives, but I encourage everyone to read what they can and talk to their kids.  (Even if they do roll their eyes.)  They deserve the best information and guidance we can provide. One helpful link may be found below: