Post-Traumatic Stress Disorder (PTSD) is a condition that is brought on by experiencing or witnessing a terrifying event. Not everyone who goes through a traumatic ordeal develops PTSD. Symptoms of PTSD include flashbacks, nightmares, disturbed sleep and/or severe anxiety that interfere with normal functioning. Recent research reports that there may be a number of genetic causes that may predispose certain people to create fear memories and subsequent PTSD symptoms.1
The mainstay of treatment for PTSD is therapy and/or medications such as antidepressants, anti-anxiety medications and antipsychotics. These medications may cause significant side effects (especially when taking more than one) and have been shown to have limited effectiveness.2,3 PTSD sufferers are desperate for effective nontoxic treatment and many have found that cannabis helps to quell the nightmares, allows for sleep and alleviates anxiety.
Understanding how cannabis may help patients with PTSD is a major focus of research as the number of military veterans with this medical condition has increased significantly over the past few decades.4
The discovery of the endocannabinoid system (ECS) and the mapping of cannabinoid receptors has revealed that cannabinoid receptors are expressed in high levels in the part of the brain called the amygdala that controls anxiety, fear memory and emotional response to stress.5 When these receptors are triggered by natural endocannabinoids or by THC, there is a reduction of anxiety and lessening of PTSD symptoms. In order to have a normal response to fear and to the resulting traumatic memories, a properly functioning ECS must be present. An abnormality in the ECS can predispose the individual to PTSD and the chronic stress that results from PTSD can further impair the functioning of the ECS, worsening the condition.
Although published research on the use of cannabis for PTSD is limited, there are some studies that show a relationship between the endocannabinoid system, PTSD and cannabis use:
It is very important to note that patients with PTSD are desperate to find a solution to their disruptive symptoms and poor quality of life. Cannabis medicine can be very useful to treat many of the symptoms of PTSD, but it is critical that PTSD patients understand the concept of receptor down-regulation with THC use. Remember that chronic heavy use of THC-cannabis can cause a decrease in receptor numbers that will lead to tolerance and eventually to a loss of effectiveness.
Patients with PTSD must be thoughtful about frequency and dosing of THC-rich cannabis so that tolerance can be minimized and effectiveness can be maximized.
I have found in my medical practice that patients using moderate doses of THC who take intermittent breaks from use (a few days up to a week after they have improved symptoms) report excellent resolution of PTSD symptoms.
Unfortunately, I have evaluated a few patients with PTSD who no longer benefit from the use of THC-rich cannabis as they are over-medicating with high potency concentrated formulations that have created a very high tolerance. A number of these patients were able to abstain from cannabis for a few weeks in order to up-regulate their receptors which resulted in positive effects when they started to use THC-rich cannabis again. Use of high CBD:THC (approximately 18:1 to 25:1) cannabis during the time of abstinence helped to minimize THC withdrawal symptoms in these patients.
I encourage my patients to include CBD in their cannabis medicine regimen as it can be quite helpful in reducing anxiety. PTSD patients using chemovars with high THCV potency anecdotally report that this phytocannabinoid also helps to decrease anxiety and can block panic attacks without causing sedation. However, chemovars with significant amounts of THCV are quite rare to find at this time. Terpenoids that may help with PTSD symptoms include myrcene for its sedating effects, linalool for its calming effects, and limonene for anti-anxiety effects. Chemovars high in pinene are discouraged as this terpenoid aids memory, which may give the opposite effect that PTSD sufferers are seeking.
Sandica, B. A., and B. Pop. “Risk Factors for PTSD.” J Trauma Treat S 4 (2014): 2167-1222.
Friedman MJ, Marmar CR, Baker DG, et al. Randomized, double-blind comparison of sertraline and placebo for posttraumatic stress disorder in a Department of Veterans Affairs setting. J Clin Psychiatry 2007;68(5):711–720.
Berger, William, et al. “Pharmacologic alternatives to antidepressants in posttraumatic stress disorder: a systematic review.” Progress in neuro-psychopharmacology and biological psychiatry 33.2 (2009): 169-180.
Trezza, Viviana, and Patrizia Campolongo. “The endocannabinoid system as a possible target to treat both the cognitive and emotional features of post-traumatic stress disorder (PTSD).” Frontiers in behavioral neuroscience 7 (2013).
Katona, István, et al. “Distribution of CB1 cannabinoid receptors in the amygdala and their role in the control of GABAergic transmission.” The Journal of neuroscience 21.23 (2001): 9506-9518.
Fraser, George A. “The use of a synthetic cannabinoid in the management of Treatment‐Resistant nightmares in posttraumatic stress disorder (PTSD).” CNS neuroscience & therapeutics 15.1 (2009): 84-88.
Neumeister, Alexander, et al. “Elevated brain cannabinoid CB1 receptor availability in post-traumatic stress disorder: a positron emission tomography study.” Molecular psychiatry 18.9 (2013): 1034-1040.
Greer, George R., Charles S. Grob, and Adam L. Halberstadt. “PTSD symptom reports of patients evaluated for the New Mexico Medical Cannabis Program.” Journal of psychoactive drugs 46.1 (2014): 73-77.
Roitman, Pablo, et al. “Preliminary, open-label, pilot study of add-on oral Δ9-tetrahydrocannabinol in chronic post-traumatic stress disorder.” Clinical drug investigation 34.8 (2014): 587-591.