Cannabis has been promoted for its ability to reduce stress and help with anxiety. Many patients self report that cannabis helps them with their anxiety and symptom. In a survey amongst 1429 medical cannabis patients, 58.1% reported they used cannabis for anxiety. But what did they use? What dose? What route of administration? High/low THC?
What Does the Evidence Says?
Surprisingly (or not) there are very few studies or randomized controlled trials on cannabis for treating anxiety as a primary diagnosis, such as Generalize Anxiety Disorder. Most of the studies are either very small trials, with different products, routes of administration and usually studying other primary endpoints, while at the same time using mostly retrospective, self reported data. There are numerous studies showing both association and no association of anxiety and cannabis use. For example:
1. In a cannabis and cancer patient study, they did report the side effects of increased anxiety with high dose THC. Several studies showed an increase in anxiety with cannabis use. PMID: 38430618.
2. In 2022, the authors compared vaporized THC, THC+CBD, CBD and placebo, in 26 patients. THC alone did induce the most anxiety, will the 1:1 THC+CBD caused anxiety, but less than the THC alone. The CBD did not impact the anxiety score versus placebo PMID: 36227352
3. In 2007, an Australian study 3239 young adults were followed from age 14 to 21, and they reported and odds ratio of 3.4 that frequent cannabis use would be more likely to report anxiety symptoms as an adult. PMID: 17314727.
4. In 2016, 8598 Swedish adults aged 20 to 64 were followed in a 3-year longitudinal cohort, and they found no statistically significant increase in anxiety at follow up. The frequency or type of cannabis was not reported. PMID: 26773900
5. In 2024, Beletsky et al. did a literature review on cannabis use and its relationship to anxiety and cannabis use disorder. They have a great summary of numerous trials showing positive and negative associations of cannabis use and anxiety. Overall, they reported a higher association on cannabis use in patients with anxiety via mostly self reporting studies. They did interpret that there is no data to suggest that cannabis is the cause of the anxiety, versus patient’s with anxiety may self-medicate with cannabis.
6. In Jan 2024, a non equivalent, controlled study did compare anxiety symptoms of non-cannabis and regular cannabis users. They compared 24% THC, 24% CBD, and 12%:12%. THC: CBD. Over 4 weeks, they found no significant increase in anxiety score with THC dominant flowers, and all products showed some improvement in scores, but they found the largest improvement was associated with the CBD dominant products. PMID: 38252547
SUMMARY: Discussion and Considerations
- There are no studies showing cannabis treating Generalized Anxiety Disorder in humans.
- CBD and THC have been reported in lab models to have association on different receptors and neurotransmitters than effect mood.
- In general, CBD is thought to have a more anxiolytic (reducing) effects, while THC tends to be more anxiogenic (increasing) effects.
- Small studies show that high THC may cause more anxiety, while THC with at least equivalent CBD may cause less anxiety than THC alone.
- It is unknown if anxiety patients tend to self medicate with cannabis or if there is a casual effect of frequent cannabis use and anxiety.
- Frequent cannabis use in youth, has an association of anxiety symptoms in adulthood.
Practical Considerations from our Pharmacist’s
- CBD appears to be a safer choice for treating anxiety versus THC alone, simply because THC may in fact induce anxiety in some patients.
- As THC dosing increases, as does the risk of anxiety symptoms in some patients.
- Frequency of cannabis use, and high THC use may increase the risk of cannabis use disorder. Some people may not believe in this condition, but there would likely some sort of risk of developing a withdrawal/tolerance syndrome.
- Cannabis use is very individualized, and some patients may respond very well to THC products, but the limited data (which was a THC: CBD 1:1 ratio) did suggest having CBD along with THC did reduce the anxiety-causing effect of THC.
- We recommend that patients using cannabis for anxiety should be done with their primary care physician/practitioner, with regular monitoring of QOL (Quality of Life) and anxiety symptom scoring.
April 2024.
***Medical cannabis is an individualized experience and patients should be consulting their health care team members before self -medicating with cannabis or any natural health product, to assess and monitor the risk for potential drug interactions or contraindications.