From the Guidelines
The current data on marijuana's efficacy for depression and anxiety is mixed and limited, and therefore, it is not recommended as a first-line treatment for either condition. While some patients report subjective improvements in symptoms, particularly for anxiety, the scientific evidence does not strongly support marijuana as a treatment for these conditions 1. For anxiety, some studies suggest that products with higher CBD and lower THC content may provide temporary relief, with typical doses ranging from 10-25mg of CBD. However, regular THC use may actually worsen anxiety and depression symptoms over time, particularly at higher doses 1.
Key Considerations
- The potential benefits of marijuana for depression and anxiety appear to be short-term, while long-term use carries risks including dependence, cognitive effects, and possible worsening of underlying mental health conditions.
- The endocannabinoid system does influence mood regulation, which explains why cannabis affects these conditions, but the complex interaction can be both beneficial and harmful depending on individual factors, cannabis composition, and usage patterns.
- Patients considering marijuana for these conditions should discuss this with healthcare providers, as established treatments like psychotherapy, SSRIs, and other medications have stronger evidence supporting their use for depression and anxiety.
Risks Associated with Marijuana Use
- Chronic cannabis use carries long-term psychiatric risks, which may be correlated with cumulative exposure including age of first use 1.
- Cannabis and/or cannabinoid use may be associated with an increased risk for developing depressive disorders and may exacerbate psychiatric disorders in vulnerable individuals.
- Ten percent of adults with chronic cannabis use may also develop cannabis use disorders, associated with clinically significant impairment or distress, including using more cannabis than expected and difficulty in cutting back on use 1.
Important Recommendations
- Clinicians should recognize that long-term daily cannabis users may experience non–life-threatening withdrawal symptoms after cessation of cannabis, including irritability, restlessness, anxiety, sleep disturbances, appetite changes, and abdominal pain 1.
- Cannabis users are also at higher risk of motor vehicle accidents, and therefore, cannabis use while driving remains a serious topic to discuss with adults using cannabis and/or cannabinoids 1.
From the Research
Efficacy of Cannabis in Treating Anxiety Disorders
- The current evidence on the efficacy of cannabis in treating anxiety disorders is equivocal, with some studies suggesting anxiolytic effects of cannabidiol (CBD) in healthy volunteers and clinical populations 2, 3, 4.
- However, the evidence regarding the use of Δ9-tetrahydrocannabinol (THC)-dominant products for anxiety is ambiguous, with exacerbation of anxiety in some individuals and relief in others 2, 5.
- Clinical trials and laboratory studies provide evidence of anxiolytic effects of CBD, but the current evidence is insufficient to support CBD as a first-line treatment for anxiety disorders 2, 3, 4.
Efficacy of Cannabis in Treating Major Depressive Disorder
- There is limited research on the efficacy of cannabis in treating major depressive disorder, with most studies focusing on anxiety disorders 6, 5.
- One study found that THC added to standard pharmacotherapy reduced self-reported nightmares in patients with posttraumatic stress disorder (PTSD), but another study found no improvement in depression symptoms in hospitalized patients with unipolar or bipolar depression 5.
- Overall, the evidence for the use of cannabinoids in mood disorders, including major depressive disorder, is insufficient, and further research is needed to investigate the safety and efficacy of managing psychiatric disorders with cannabinoids 5.
Prescribing and Usage of Cannabis for Anxiety Disorders
- Despite the lack of robust supportive evidence, prescription of medicinal cannabis products for anxiety is increasing rapidly, with approximately 17% of current prescriptions for anxiety being for CBD-dominant products and 33% for THC-containing products 2.
- Medical practitioners should carefully consider potential risks and benefits when prescribing medicinal cannabis for anxiety disorders and should 'start low and go slow' 2.
- Illicit cannabis is widely used in the community to self-medicate anxiety, highlighting the need for further research and education on the potential benefits and risks of cannabis use for anxiety disorders 2, 3.