Q: Can cannabis help with anxiety and depression?
A: According to the CDC, anxiety and depression are two of the most common mental health conditions seen in the US, seen in about 20 percent of the population. Symptoms of anxiety can include excessive worry, fear, apprehension, and rumination with intrusive thoughts, and can be associated with physical symptoms such as sweating, high heart rate, high blood pressure, and abdominal pain. And symptoms of depression can be feelings of extreme sadness, despair, worthlessness, and hopelessness, and it can also cause physical symptoms of pain, weight gain or loss, and inability to sleep and concentrate. Both conditions interfere with your daily life.
These conditions are very complicated mood disorders that do not have an exact cause but are probably a combination of genetic, biological, environmental, and psychological factors. However, we know that our endocannabinoid system (ECS) plays a critical role in our mental health. We have internal cannabinoids called endocannabinoids and they attach to our cannabinoid receptors (CB1 and CB2) in the brain to regulate our central nervous system. These compounds such as anandamide, which is also called the bliss molecule, have been found to have anti-anxiety and antidepressant effects. And there are abundant CB1 receptors in areas of the brain that control emotions, mood, and fear. These areas are called the amygdala, hippocampus, prefrontal cortex, and anterior cingulate cortex.
A 2016 review study published in Nature discusses how our endocannabinoid system regulates and buffers stress in these parts of our brain.
Many animal studies of the endocannabinoid system find that this system is integral to managing anxiety. For instance, a study done in mice bred to have no cannabinoid receptors showed they had high anxiety levels compared to normal mice.
The enzyme that breaks down anandamide is called fatty acid amide hydrolase (FAAH). Mice that are bred without this enzyme have more of this bliss molecule in their brains and have been found to be less anxious than normal mice.
Human studies also find that dysfunction in our ECS can affect our mood and contribute to anxiety and depression.
We have another internal endocannabinoid called 2-Arachidonoylglycerol (2-AG). A study found that women with lower levels of this endocannabinoid were more likely to have major depression. The same researchers also found depressed patients who had lower blood circulating levels of anandamide were more likely to report anxiety. All this contributes to the theory that at least one of the factors in mental health conditions might be the dysfunction or deficiency of our internal endocannabinoid system.
Our cannabinoid receptors (CB1 and CB2), interact with the cannabinoid compounds found in cannabis, such as THC and CBD. And THC and CBD can also interact with other brain neurochemical receptors that have been found to have a role in anxiety and depression, such as serotonin. In fact, many of the prescription anti-anxiety and antidepressant drugs on the market target this serotonin receptor. These medications are called Selective Serotonin Reuptake Inhibitors (SSRI). One example is a drug called Fluoxetine (brand name: Prozac).
This is why there is a fair amount of research looking into the use of cannabis for mental health conditions such as anxiety and depression. But, at present, the evidence is still somewhat limited. To find some of the stronger scientific evidence supporting the idea that cannabis could help with mental health, look at animal studies in rodent models that suggest that THC and CBD may have similar effects to antidepressant medications.
THC can augment anandamide’s action at the CB1 receptors, but it is dose-dependent. A 2005 study found that low doses can have anti-anxiety and antidepressant effects, while high doses can actually trigger anxiety and depression.
An older study from the 1980s found that CBD can have anti-anxiety properties in both low and high doses, and can mitigate anxiety produced from THC intake, as well as its intoxicating effects.
A recent study from 2019 was a large case series looking at CBD use in anxiety and sleep. They found 80 percent of patients reported decreased anxiety within the first month of the study that lasted for its duration. Another study looking at cannabis use in young adults found 87 percent reported they used it to elevate their depressed mood.
And there are studies that corroborate the belief that many patients have, namely higher CBD to THC ratios seem to work better for their anxiety and depression.
Additionally, with respect to adolescent patients, there is a lot of older research showing the potential harm of cannabis in the developing adolescent brain. But this research was looking at teens that were not medical patients with documented ECS dysfunction under the care of a doctor, but instead using high THC levels of cannabis recreationally. And today even the National Institute on Drug Abuse (NIDA) admits on their website while there may be a link to mental health conditions in adolescents who use cannabis frequently, there is no evidence yet that cannabis actually causes these conditions.
All this is compounded by the fact that psychiatric illnesses such as bipolar and schizophrenia usually first emerge and present during the adolescent and young adult years, so it is possible that many of these people were having symptoms of a mental illness and were trying to self-medicate.
And we know there are known genetic mutations, in the genes called COMT and AKT1, which are related to the production and metabolism of neurochemicals in the brain such as dopamine and glutamate that can predispose someone to develop both psychosis and cannabis use disorder.
Therefore, it is very important to talk with a physician or mental health professional if you are having symptoms of anxiety and depression. Please do not self-medicate with cannabis! And if you have recurrent thoughts of harming yourself, death or suicide immediately call the national 988 Suicide and Crisis Lifeline. People are available 24/7 to help and please know that you are not alone.
Dr. Leigh Vinocur is a board-certified emergency physician who also has a cannabis consulting practice for patients and industry. She is a member of the Society of Cannabis Clinicians and a graduate of the inaugural class, with the first Master of Science in the country in Medical Cannabis Science and Therapeutics from the University of Maryland School of Pharmacy.
Originally published on greenstate.com on January 17, 2023 —