Cannabis Information for Older Adults

Last revised: December 5, 2023

Cannabis is a plant that has chemicals called cannabinoids. The most common cannabinoids are THC (tetrahydrocannabinol) and CBD (cannabidiol). 

  • THC affects your brain to make you feel “high” and changes how you think, feel and act. The higher the level of THC, the greater the intoxicating effects.  
  • THC is mostly responsible for the health risks associated with cannabis.
  • CBD does not cause intoxicating effects and can lessen the THC effects. CBD is being studied for possible medical uses.

Everyone’s response to cannabis is different and can vary from one time to the next.  If you have used cannabis earlier in life, the effects today can be different because the THC potency in cannabis has increased. Older adults are more likely to experience harm from cannabis because of age-related changes.

The aging process can affect how older adults respond to cannabis

As we age, our body and mind functions begin to slow down. Some of these changes will affect how THC and CBD are processed in the body.

  • Lower kidney function can affect how drugs, including cannabis, are cleared out of the body.
  • Symptoms of poor lung health or disease can be worsened when cannabis is smoked or vaped.
  • The digestive system slows down, and liver function is reduced, affecting how the body processes and removes cannabis from the body.
  • Changes to muscles, bones, and sensory functions (vision, hearing and smell) can increase the risk of falls or injuries. This risk would be higher when using THC because it is impairing.

Older adults with a heart condition are at greater risk for a heart attack or stroke

Smoking cannabis can raise your heart rate and blood pressure. This increases the risk of a cardiac event such as arrhythmia, angina, heart attack or stroke, for those with heart conditions.

Cannabis can lower your blood pressure, which can cause people to faint.

Cannabis can affect prescription and over the counter medications

Cannabis is a substance (drug) and can affect how other medications work. If you are currently taking any prescription or over-the-counter medications, it is important to talk to your health care provider or pharmacist. They can assess any interaction cannabis may have with your medications. 

Cannabis affects how your brain works

THC acts on different parts of the brain to change how you think, feel and act. This can include feeling high, having trouble concentrating, slower reaction, and distorted perceptions. These effects can last between 6 to 12 hours depending on the amount of THC and the method of use. These changes increase the chance of injuries and make it unsafe to drive.

Regular use of THC can cause problems with how your brain works. This can include mental abilities such as memory, concentration, thinking and making decisions.

Using cannabis (THC) as a teenager can lead to lasting effects on your mental abilities as you get older. THC changes how the brain develops and how it works when you use cannabis often at an early age. These changes can be permanent even if you have stopped using cannabis.

Cannabis can lead to mental health challenges

Older adults can experience loneliness, isolation, depression or loss. Using cannabis to cope could make mental health challenges worse.

Regular use can lead to a cannabis use disorder or dependence. If you are dependent, it can be hard to cut back or stop using. It can cause unpleasant feelings like:

  • Feeling irritable or anxious,
  • Having an upset stomach,
  • Trouble sleeping,
  • Loss of appetite and
  • Sweating.

Using cannabis can raise the risk of experiencing psychosis and schizophrenia if you have a family history of these conditions. Temporary psychosis is possible if you consume too much THC at one time. Symptoms include paranoia, delusions and hallucinations.

Lower risk cannabis use

Due to the health risks, older adults with the following conditions should consider not using cannabis:

  • Heart conditions or unstable blood pressure
  • Cognitive impairments or problems with balance
  • History of mental health challenges or substance use disorders

If you are planning to use cannabis, read more information about using legally and follow these lower risk tips.

Using cannabis for medical purposes

Choosing to use cannabis for medical purposes should be done in consultation with a health care provider. The evidence of the effectiveness and safety of cannabis for treating medical conditions is still emerging. The limited evidence that is available is not specific to older adults. There are studies that show some potential medical benefit for the use of cannabis in these specific cases such as:

  • Nausea and vomiting from chemotherapy
  • Muscle contractions or stiffness associated with multiple sclerosis
  • Chronic neuropathic pain
  • Palliative and end-of-life pain

For more information, visit Health Canada on Medical use of cannabis and Consumer information on Cannabis.

For more information on resources and services, visit our Mental Health, Addictions and Substance Use Health Services and Resources webpage.

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