CBD or THC for Chronic Illness and Sleep: What the Evidence Actually Says
She has lived with fibromyalgia for eight years. Most nights, the pain wakes her two or three times, and mornings start with exhaustion before the day has even begun. Her doctor has tried several medications, some with side effects she could not tolerate. A friend swears by a CBD oil, and another uses a THC gummy every night "to finally sleep." The cannabis store down the street has shelves of products promising calm, relief, and rest. She wants to feel better. She also wants to know whether any of it actually works, and what the risks might be.
Since cannabis was legalized in Canada in 2018, many people living with chronic pain, illness, and sleep problems have turned to CBD and THC for relief. Some describe real benefits. Others find the results disappointing, or end up with new problems. This post explores what CBD and THC are, what the research says about chronic pain and sleep, what to watch for, and how to make informed choices alongside your health care team.
CBD and THC: what is the difference?
Cannabis contains many active compounds. The two best known are:
THC (tetrahydrocannabinol) is the main compound responsible for the "high." It can affect mood, perception, appetite, pain, and sleep.
CBD (cannabidiol) does not produce a high in the same way. It is often marketed for relaxation, anxiety, pain, and sleep, although the evidence for many of these uses is still limited.
Products vary enormously, from CBD-only oils to high-THC flower, edibles, and vapes, and their effects depend on the dose, the ratio of THC to CBD, how they are taken, and the person using them. In Canada, both THC and CBD products are regulated under the Cannabis Act.
What the research says about chronic pain
Chronic pain is one of the most common reasons people try cannabis. A large systematic review of 32 randomized controlled trials, involving more than 5,000 adults with chronic pain, found that non-inhaled medical cannabis or cannabinoids produced a small to very small improvement in pain relief compared with placebo (Wang et al., 2021). The same review found small increases in side effects such as dizziness, drowsiness, nausea, and difficulty concentrating.
In other words, cannabis may help some people a little, but for most, it is not the dramatic solution it is sometimes marketed as. Some people find even a small improvement worthwhile, especially when other options have not worked or have caused intolerable side effects. That is a personal decision best made with your doctor.
What the research says about sleep
Many people use cannabis to fall asleep or stay asleep. The evidence here is surprisingly mixed.
In the chronic pain review mentioned above, oral cannabis produced a small improvement in sleep quality (Wang et al., 2021). However, an earlier systematic review of research on cannabinoids and sleep found inconsistent effects, and concluded that methodological problems in many studies made it impossible to draw firm conclusions (Gates et al., 2014).
There is also an important catch. People who use cannabis regularly for sleep can develop tolerance, needing more to get the same effect. When they stop, they may experience withdrawal symptoms, which can include difficulty sleeping and vivid or unusual dreams (American Psychiatric Association, 2022). For some, this creates a cycle in which cannabis seems necessary for sleep, partly because stopping makes sleep worse.
For chronic insomnia, cognitive behavioural therapy for insomnia (CBT-I) is recommended as a first-line treatment for adults (Qaseem et al., 2016). It addresses the thoughts, habits, and patterns that keep insomnia going, and its benefits tend to last after treatment ends.
What to watch for
Product labels may not be accurate. In one study of CBD products sold online, only about a third were accurately labelled for CBD content, and some contained THC that was not listed (Bonn-Miller et al., 2017). Buying from legal, regulated sources reduces, but does not eliminate, this risk.
THC carries more risks than many people realize. Canada's Lower-Risk Cannabis Use Guidelines recommend choosing products with lower THC and higher CBD, avoiding daily or near-daily use, and not driving for at least six hours after using cannabis (Fischer et al., 2017). The guidelines also advise that people with a personal or family history of psychosis or substance use disorders, and people who are pregnant, should not use cannabis.
Mental health effects matter. High-THC products and frequent use are associated with greater risks, including anxiety, worsening mood for some people, cannabis use disorder, and, in vulnerable individuals, psychosis.
Medication interactions are possible. CBD and THC can interact with other medications, including some blood thinners, seizure medications, sedatives, and antidepressants. Always tell your doctor and pharmacist what you are using, including over-the-counter or recreational products.
Combining with alcohol or sedatives increases risk. Mixing cannabis with alcohol, sleep medications, or opioids can increase drowsiness and impairment.
Making informed choices
If you are considering cannabis for chronic illness or sleep, it may help to:
Talk with your doctor or nurse practitioner first, especially if you have other health conditions or take medications.
Ask about medical cannabis authorization if appropriate, so your use is guided and monitored.
Start with a low dose, go slowly, and favour products with lower THC.
Keep track of what you use and how it affects your pain, sleep, mood, and daily functioning.
Reassess regularly. Ask yourself whether it is still helping, and whether the benefits outweigh any downsides.
Consider evidence-based alternatives, such as CBT-I for insomnia, and pain management approaches that address both the body and the mind.
The emotional side of chronic illness
Living with chronic pain or illness is exhausting, and it can affect every part of life: work, relationships, identity, and mood. Poor sleep makes everything harder. It is entirely understandable to look for anything that might help. Whatever choices you make about cannabis, support for the emotional weight of chronic illness can make a meaningful difference. Therapy can help with the grief, frustration, anxiety, and isolation that often come with ongoing health challenges, and with the habits and thought patterns that make sleep harder.
When to reach out for support
It may be worth speaking with a professional if you are using cannabis more often or in larger amounts than you intended, if you feel unable to sleep without it, if it is affecting your mood, memory, motivation, or relationships, or if you are struggling emotionally with chronic pain or illness. If you are having thoughts of suicide, please reach out right away.
Reflection questions worth exploring
These prompts are best explored with a professional or a trusted person rather than used to reach conclusions on your own.
What am I hoping cannabis will help with?
How has my use changed over time?
How do I feel the next day, physically and emotionally?
What else have I tried for pain or sleep, and what has helped?
How is my chronic illness affecting my mood, relationships, and sense of self?
Support at Vive Wellness Therapy
At Vive Wellness Therapy, we support people living with chronic pain, chronic illness, and sleep difficulties, as well as those exploring their relationship with cannabis or other substances. We offer a non-judgemental space to explore what is helping, what is not, and how to care for both your body and your mind. If you would like support, we would be glad to hear from you whenever you feel ready.
References
American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed., text rev.). https://doi.org/10.1176/appi.books.9780890425787
Bonn-Miller, M. O., Loflin, M. J. E., Thomas, B. F., Marcu, J. P., Hyke, T., & Vandrey, R. (2017). Labeling accuracy of cannabidiol extracts sold online. JAMA, 318(17), 1708–1709. https://doi.org/10.1001/jama.2017.11909
Fischer, B., Russell, C., Sabioni, P., van den Brink, W., Le Foll, B., Hall, W., Rehm, J., & Room, R. (2017). Lower-risk cannabis use guidelines: A comprehensive update of evidence and recommendations. American Journal of Public Health, 107(8), e1–e12. https://doi.org/10.2105/AJPH.2017.303818
Gates, P. J., Albertella, L., & Copeland, J. (2014). The effects of cannabinoid administration on sleep: A systematic review of human studies. Sleep Medicine Reviews, 18(6), 477–487. https://doi.org/10.1016/j.smrv.2014.02.005
Qaseem, A., Kansagara, D., Forciea, M. A., Cooke, M., & Denberg, T. D. (2016). Management of chronic insomnia disorder in adults: A clinical practice guideline from the American College of Physicians. Annals of Internal Medicine, 165(2), 125–133. https://doi.org/10.7326/M15-2175
Wang, L., Hong, P. J., May, C., Rehman, Y., Oparin, Y., Hong, C. J., Hong, B. Y., AminiLari, M., Gallo, L., Kaushal, A., et al. (2021). Medical cannabis or cannabinoids for chronic non-cancer and cancer related pain: A systematic review and meta-analysis of randomised clinical trials. BMJ, 374, n1034. https://doi.org/10.1136/bmj.n1034
This article is provided by Vive Wellness Therapy for general informational and educational purposes only. It is intended to be used alongside professional therapy and medical care and is not a substitute for assessment, diagnosis, or treatment by a qualified health professional. It does not provide medical advice about cannabis or any medication; please speak with your doctor, nurse practitioner, or pharmacist before starting, changing, or stopping any substance or treatment. Research, clinical guidance, and regulations evolve over time, and information in this article may become outdated or contain inaccuracies. If you are in crisis or thinking about suicide, call or text 9-8-8 (Suicide Crisis Helpline, available 24/7 across Canada; in Quebec, calls connect to 1-866-APPELLE). If you or someone else is in immediate danger, call 9-1-1 or go to your nearest emergency department.
