Four other human trials from 2012 to 2016 suggest CBD reduces PTSD symptoms, although some include THC, or tetrahydrocannabinol, the main mind-altering element in cannabis. When THC and CBD work together, they create what’s called an “entourage effect,” complementing each other’s benefits and potency. For example, taking the same dose of THC and CBD together tempers the “high” from THC, while just a little THC paired with more CBD enhances the effects of the CBD.
Meanwhile, continued studies in the U.S. indicate CBD is effective in treating chronic, non-cancer pain. In one 2020 study, researchers administered CBD topically to a group of patients with symptomatic peripheral neuropathy (a result of brain nerve and spinal cord nerve damage) while another group with the same condition received a placebo. Results showed a significant reduction in intense, sharp pains and cold, itchy sensations in those who used the topical CBD compared to those who used the placebo. No participants reported adverse side effects.
4. Treat Opioid Addiction
CBD is often extracted from the cannabis sativa plant in oil form and mixed with an inert carrier oil like hemp seed oil for consumption. In recent years, CBD oil has skyrocketed in popularity thanks to its purported calming effects. It can now be found in a range of products from simple oil tinctures to CBD-infused potato chips.
In 2005, Canada approved the use of Sativex, an oromucosal (absorbed in the lining of the mouth) spray with equal proportions of THC and CBD, for the treatment of multiple sclerosis-related central neuropathic pain. In 2007, Canada approved the medicine’s use again for cancer pain that proved unresponsive to other medications.
Some studies—both preclinical animal and human clinical trials—suggest CBD could be used to help treat people who are dependent on opioids.
In June 2018, the U.S. Food and Drug Administration (FDA) approved Epidiolex, a CBD oral solution used for the treatment of certain rare forms of epilepsy in children under 2—Dravet syndrome and Lennox-Gastaut syndrome. Both are exceptionally rare genetic disorders causing lifelong catastrophic seizures that begin during the first year of life.
In all but a few studies, lower doses of CBD (10 milligrams per kilogram, mg/kg, or less) improved some symptoms of anxiety. Higher doses (100 mg/kg or more) exhibited virtually no effect.
Outside of these two disorders, CBD’s effectiveness in treating seizures is uncertain. Even with Epidiolex, it is uncertain whether the anti-seizure effects can be attributed to CBD or some other factor.
According to a 2012 study in the Journal of Experimental Medicine, rats injected with inflammatory chemicals in their hind feet experienced less inflammation and neuropathic pain when treated with an oral dose and spinal injection of CBD.
CBD oil may also increase liver enzymes (a marker of liver inflammation). People with liver disease should use CBD oil with caution, ideally under the care of a doctor who can regularly check blood liver enzyme levels.
The tricky part is calculating the exact amount of CBD per milliliter of oil. Some tinctures have concentrations of 1,500 mg per 30 mL, while others have 3,000 mg per mL (or more).
However, the effect of CBD on each addiction type was often very different. With opioid addiction, for example, CBD showed little effect in minimizing withdrawal symptoms in the absence of THC. By contrast, CBD on its own appeared effective in minimizing drug-seeking behaviors in users of cocaine, methamphetamine, and other psychostimulant drugs.