The Endocannabinoid System, Cannabinoids and Anxiety
The endocannabinoid system and its role in mental health
There is increasing evidence suggesting the endocannabinoids system plays an important role in the regulation of stress, mood and psychiatric disorders.1 Pharmacological or genetic disruption of endocannabinoid signaling in animals produces a neurobehavioural response that mimics the classical stress response including activation of the HPA axis, increased anxiety, suppressed feeding behaviour, reduced responsiveness to rewarding stimuli, hypervigilance and arousal, enhanced grooming behaviour and impaired cognitive flexibility.1
In periods of acute or chronic stress, there appears to be a reduction in the endocannabinoid anandamide.1 This is thought to lead to the increase in anxiety, HPA axis activity and other symptoms of mood disorders.1
Evidence supporting the role of cannabis for anxiety
One of the most common reasons for the consumption of medical cannabis is for the reduction of anxiety or stress.2 Until recently, there was very little evidence on the potential role of cannabis in anxiety management
Health Canada’s Information for Health Care Professionals: Cannabis (marihuana, marijuana) and the cannabinoids was published in October 2018. This extensive systematic review analyzed pre-clinical and clinical data on the cannabis evidence for the management of anxiety. The anxiety findings from this systematic review are found in Table 1
|Table 1 – Cannabis and Anxiety1 1|
|THC has a biphasic effect on mood||
|THC and cannabinoids improve anxiety and depression in people with chronic illnesses||
|CBD exhibits an anxiolytic benefit||
|Equal portions of THC and CBD cannabis can attenuate anxiety and depression with high THC cannabis||
Patients use cannabis for anxiety
Patient survey data from medical cannabis users suggest that anxiety/stress is one of the most common reasons for medical cannabis use.2 These observational studies have reported significant effect on anxiety-related symptoms with a low incidence of adverse effects.2 One observational study found that approximately two-thirds of medical cannabis users were able to reduce the use of other prescription medications.3 A significant portion of these patients were able to reduce or stop medications for anxiety such as benzodiazepines and antidepressants.
Health Canada. Information for Health Care Professionals: Cannabis (marihuana, marijuana) and the cannabinoids. aem. https://www.canada.ca/en/health-canada/services/drugs-medication/cannabis/information-medical-practitioners/information-health-care-professionals-cannabis-cannabinoids.html. Published October 12, 2018. Accessed October 15, 2018.
Morin CM, Benca R. Chronic insomnia. The Lancet. 24;379(9821):1129-1141. doi:10.1016/S0140-6736(11)60750-2
Webb CW, Webb SM. Therapeutic Benefits of Cannabis: A Patient Survey. Hawaii J Med Public Health. 2014;73(4):109-111.
Roth T. Comorbid insomnia: current directions and future challenges. Am J Manag Care. 2009;15 Suppl:S6-13.
Lucas P, Walsh Z. Medical cannabis access, use, and substitution for prescription opioids and other substances: A survey of authorized medical cannabis patients. Int J Drug Policy. 2017;42:30-35. doi:10.1016/j.drugpo.2017.01.011