Sublingual Cannabidiol for Anxiety

Cannabis has been used for medicinal purposes across many cultures for a range of disorders for thousands of years. The plant is comprised of a variety of components, such as phytocannabinoids, which include (among others) the major intoxicating constituent of cannabis, delta-9 tetrahydrocannabinol (THC), and cannabidiol (CBD), a major non-intoxicating constituent of cannabis. Increasing evidence indicates that CBD in particular may have significant medicinal properties and benefits; experimental studies in both animals and humans have demonstrated that CBD can act as an anticonvulsant, antipsychotic, and muscle relaxant. Several studies have demonstrated that CBD produces acute anxiolytic effects in animals and humans, although thus far no clinical trials of CBD have been conducted in patients with anxiety. As a growing number of states are legalizing medical cannabis, a gap exists in the scientific literature regarding the effects of CBD on anxiety.

This investigation is composed of two stages. Stage 1 is comprised of a four-week, open-label clinical trial of a high-CBD containing compound in individuals with anxiety. Participants will be pre-screened by phone in order to evaluate their eligibility for the study. If approved, participants will come to the hospital for a baseline/screening visit, and will complete a structured clinical interview, clinical and quality of life questionnaires, and cognitive assessments. Enrolled participants will be given CBD solution to use for the duration of the study; participants will be instructed to self-administer 1 milliliter (ml) of the tincture under the tongue three times per day for four weeks. Throughout the treatment period, participants will return to the hospital on a weekly basis to complete questionnaires about their mood and quality of life. Participants will also return to the hospital for a final visit after four weeks of treatment to complete additional questionnaires and cognitive assessments. Stage 1 of the study was completed in early 2020.

Stage 2 of the study is a double-blind clinical trial of this solution in patients with anxiety. This double-blind trial began after the open-label trial was completed. In the same manner as the open-label trial, participants will be pre-screened by phone, and approved participants will come to the hospital for a baseline/screening visit to complete a structured clinical interview, questionnaires, and cognitive assessments. Eligible participants will also have the option to complete an hour-long MRI scan at the baseline and final visits. Enrolled participants will receive either full-spectrum CBD solution, single-compound CBD solution, or placebo solution to self-administer throughout the four week treatment period, as described above. Participants will return to the hospital weekly during the treatment period to complete questionnaires about their mood and quality of life. Participants in this stage of the study will also return for a final visit after four weeks of treatment to complete additional questionnaires, cognitive assessments, and an optional hour-long MRI scan.

Inclusion criteria

• 18 or older
• Native English speaker or acquired English prior to age 5
• Provides informed consent
• Endorses moderate or severe anxiety at the screening visit

Exclusion criteria

• Non-native English speakers
• Estimated IQ < 75
• Pregnancy
• Presence of serious medical illness, including liver or kidney disease, neurological disorder, or certain psychiatric disorders
• History of head injury or loss of consciousness >5 minutes
• Current use of cannabis or cannabinoid products >1x/month