Health Matters by Dr.Paul: Cannabis: Legal Does Not Mean Harmless

As we enter a new era of legalized non-medicinal marijuana (cannabis) in Canada, I want to address some common related questions. Note that even before legalization, Canadians were among the highest users of cannabis in the world. Furthermore, there are several states in the USA that have legalized marijuana. So we do have considerable knowledge about this drug.  Based on these experiences and lessons learned, we know that cannabis is not harmless although it is now legal in Canada.

What is Cannabis?

Cannabis is the scientific name for the marijuana plant that contains over 100 chemicals called cannabinoids. THC (delta-9-tetrahydrocannabinol) the main mind-altering cannabinoid, is responsible for affecting how we feel, think and act. CBD(cannabidiol) is another cannabinoid that has little or no psychoactive effects and can even offset the effect of THC. Cannabis can be smoked, vaped or ingested.  When smoked or vaped the effects are felt within a few minutes. However, when eating an edible cannabis product, the effects may only be felt 1 to 2 hours later.

What are the health effects of cannabis?

Cannabis causes one to feel of relaxed, be more sociable and feel “high”.  While the physical effects vary, the most common ones include irritated respiratory system from smoking, increased appetite, increased heart rate, difficulties with balance and stability, poor memory, difficulty thinking and distorted perceptions. (you can see how cannabis use can cause impaired driving).

Can cannabis affect mental health? 

Anyone with a personal or family history of mental health problems is at greater risk for cannabis-related psychosis and mental health problems.Adolescents and young adults (under age 25) with a personal or family history of mental health problems are at an even greater risk.

What are the specific concerns of cannabis among youth and young adults?

Because the human brain is not fully mature until about 25 years of age, any chemical that targets it during this time can cause negative effects. Cannabis is one of these chemicals that can interfere with normal brain development. When used at an early age the long-term “brain” effects include decreased memory, thinking ability and attention span. The higher the frequency of use, the higher the risks.  In addition, the younger the age of starting, the higher the risk of mental health problems and dependence. Therefore, expert guidelines recommend not starting cannabis before the age of 25. For those who are younger and still want to experiment, low risk guidelines recommend going low and slow and avoid frequent use. To be clear, the later in life one initiates cannabis use, the less potential for long-term adverse effects.

Is cannabis stronger today than it was several decades ago?

Yes, THC concentrations today are almost 4 times higher than they were in the 1960s. In fact, another low risk guideline recommendation is to use products that contain lower THC levels and higher CBD levels. In other words, a high CBD to THC ratio.

The bottom line is that although non-medicinal use of cannabis is now legal in Canada and several US states, it can cause long-term harm in youth and young adults. Smoking or vaping cannabis in front of children should also be discouraged. On a final note, because of the above effects, pregnant women and breastfeeding mothers should not use cannabis products.

Health Matters Index Page