Recent studies have shown cannabidiol (CBD) to have therapeutic effects in the treatment of post-traumatic stress disorder (PTSD), with one study showing 91% of patients experiencing a reduction in symptom severity after eight weeks of treatment.
CBD and THC are two compounds found in cannabis. CBD is a phytocannabinoid, or a chemical that is naturally synthesized by the cannabis plant. Tetrahydrocannabinol (THC), the primary active compound of cannabis, is a psychoactive compound that has been discovered to act in opposition to CBD in certain cases.
“Although both compounds have the same molecular formula, THC binds to the CB1 receptor whereas CBD prevents this process through altering the shape of the receptor,” Dr. Paul Xiaojing, a Central South University associate researcher said.
CBD and THC both act on the body’s endocannabinoid system, which regulates pain, mood, appetite and other cognitive functions. When THC or CBD is ingested, these compounds bind to the cannabinoid receptors CB1 and CB2. While THC’s structure allows it to bind to the CB1, CBD can act as an antagonist and block the binding of THC by changing the shape of the receptor. The receptor and THC act like a lock and key mechanism whereas the function of CBD is to change the shape of the lock. What determines the overall effect of a cannabis strain is the ratio of THC to CBD. If there is a high THC to CBD ratio, a user will experience the stereotypical ‘high’ associated with marijuana use. However, increasing the concentration of CBD will produce a more calming sensation that can help reduce anxiety and inflammation.
“There has been a recent surge of interest in the use of cannabinoids to treat PTSD, particularly from military veterans,” Dr. Chandni Hindocha, a research fellow within the clinical psychopharmacology unit at the University College London said.
PTSD is a mental health issue that involves anxiety-induced responses to triggers caused by a traumatic event. According to a recent study, as many as 10% of individuals are affected by the disorder at some point in their lives with 3.6% of the current US adult population experiencing it within the past year. Research in this field has been growing in popularity as many individuals diagnosed with PTSD self-medicate using CBD.
One principle of PTSD treatment is fear extinction, or the gradual reduction of adverse responses to potential triggers. Although CBD shows promising results in alleviating the symptoms of PTSD — which often include recurring nightmares, anxiety, depression, insomnia and emotional disengagement — more research is needed in its effectiveness in fear reduction.
A recent University College London study examined the effects of cannabinoids (THC and CBD) as a potential method for inducing fear extinction in humans.
“Both THC and CBD have been found to increase fear extinction in human experimental models but this needs to be investigated in more detail,” Hindocha said.
Current research indicates that it offers a temporary alleviation of symptoms rather than a cure. If a patient with the disorder were to stop taking CBD, they would experience a resurgence of symptoms.
One of the current treatments for PTSD is cognitive behavior therapy, which involves changing behavioral responses through methods including exposure and desensitization. Patients are exposed to the source of their anxiety in a controlled environment and gradually become accustomed to it.
“The research being done on CBD as a form of treatment represents the new pharmacological avenues being explored as an alternative to behavioral therapy,” Xiaojing said, “Although technological advancements like virtual reality therapy have revolutionized how we treat the disorder, the push for drug-based therapies are the result of trying to find a more accessible treatment for the general population.”
Virtual reality exposure (VRE) therapy has been used with some success to place soldiers in simulations of military activities. However, VRE often requires extensive participation on the therapist’s or clinician’s part as they need to closely monitor patient response to the simulation. As a result, there have been continued efforts to find a more cost-effective pharmacological alternative. Although antidepressants, such as selective serotonin reuptake inhibitors, are one of the currently approved methods of treating PTSD, only 30% of users experience complete remission of all symptoms.
“Couldn’t CBD, possibly enhancing the endocannabinoid system, also facilitate the extinction of aversive memories?” says Dr. Rafael Bitencourt, Laboratory of Neuropsychopharmacology researcher at the University of South Santa Catarina, “If true, it would be an exciting alternative, as it is a constituent present in cannabis that does not have the psychoactive and even adverse effects of THC and still has a wide margin of safety.”
While CBD has shown promising results in reducing the symptoms of PTSD, research in this subject has been limited. Future studies in this area look to other psychoactive drugs that potentially could have a more pronounced effect than CBD.
“Regarding the field of pharmacotherapy for PTSD, I have observed with great enthusiasm the studies showing the use of MDMA-assisted therapy,” Bitencourt said, “Possibly psychedelic drugs are by far the newest and most promising treatment.”