Experiencing a traumatic event — or events — is a common part of the human experience. After experiencing such an event, many people will develop post-traumatic stress disorder (commonly known as PTSD): one out of 10 men; two out 10 women. Among populations exposed to combat, the rate is even higher (up to 30%) — which is of particular concern given our perpetual state of war for over a decade.
The Department of Veteran Affairs reports the rate of PTSD among veterans to be: 11-20% of veterans from the Afghanistan and Iraq wars; 10% from the Persian Gulf War; and, 30% from Vietnam.
Because those suffering from PTSD continually experience pain and a whole host of symptoms that can be life disruptive, many treat their symptoms not only with doctor-prescribed pharmaceutical drugs, but often self-medicate with drugs or alcohol. Alcohol and most illicit drugs are known to worsen symptoms in the long run.
Many turn to cannabis to treat their symptoms, and until recently the medical community associated cannabis with alcohol and other drugs; they saw it as an escape for patients, not a viable treatment option. However, with ever-growing numbers of patients claiming that cannabis was often the only substance that truly provided them with symptom relief, physicians and scientists began taking their claims more seriously. And, over the last few years research has shifted from investigating cannabis as a drug of abuse, to a drug with potentially huge therapeutic value.
Thus far, the majority of animal studies and human experimental, clinical, and epidemiological studies suggest cannabis may, in fact, be a powerful tool to help PTSD patients. While most research have been animal studies (keep in mind, “mice are not men), the results have been encouraging, suggesting cannabinoids may be able to:
- Improve memory processing (e.g. facilitating fear memory extinction) to help patients eliminate the interference of traumatic memories on basic life functioning
- Inhibit nightmares and promote improved sleep function
- Prevent the effects of stress on emotional function
- Produce anti-anxiety-like effect in a variety of tasks
Although we lack a significant number of “gold standard” trials, and most research is still early, the scientific evidence we’ve accumulated explains the mechanistic actions of cannabis to treat PTSD, combined with a large body of anecdotal evidence has convinced many in the medical and scientific communities that cannabis is “real medicine” to treat PTSD. In fact, countries such as Canada and Israel, and several states in the U.S. accept PTSD as a qualifying condition for their clinical cannabis programs.
Nonetheless, people want to know if the benefits of cannabis outweigh potential risks. Should it be used as a primary treatment or an adjunct to other treatment? This article will help you draw your own conclusions. But, first, it’s important to have foundational understanding of what PTSD is and how it differs from other stress and anxiety-related disorders. Let’s start with the basics...
What is PTSD?
The National Center for PTSD (the U.S. Department of Veterans Affairs) characterizes PTSD as “a mental health problem that some people develop after experiencing or witnessing a life-threatening event, like combat, a natural disaster, a car accident, or sexual assault.. They explain that while it’s “normal to have upsetting memories, feel on edge, or have trouble sleeping after this type of event… [those] who experience these feelings for several months may have PTSD.”
What Symptoms Are Associated With PTSD?
Symptoms generally develop within six months of the traumatic event (although a significant delay in onset is not uncommon). When symptoms persist for more than three months, the condition is considered Chronic PTSD.
Common symptoms (that can be highly disruptive in relationships) include
- Persistent avoidance of people, places, and things that cause the individual significant distress
- Difficulty experiencing a normal spectrum of emotions
- Lowered expectations of an individual's ability to live a long and fulfilling life
- Difficulty sleeping or insomnia including nightmares
- Irritability and anger; poor concentration
- Exaggerated responses (hypervigilance) to ordinary events
PTSD patients often have disruptive memory processing: enhanced fear learning; impaired fear memory extinction; a propensity to encode false memories.
It’s also not unusual for sufferers to experience a number of physical health effects including drug or alcohol abuse, chronic pain, asthma, hypertension, heart diseases, obesity. PTSD is often accompanied by other disorders including generalized anxiety disorder, major depression, substance use disorder.
How is PTSD Diagnosed?
Trained mental health professionals diagnose patients according to criteria established by the American Psychiatric Association in the Diagnostic and Statistical Manual of Mental Disorders (known as the DSM-V). In a typical diagnostic session, a mental health professional will conduct a 30-60 minute interview assessment called the Clinician-Administered PTSD Scale (CAPS) that corresponds to the DSM criteria to make a diagnosis.
To help monitor how a patient is doing at a given time point and how they are responding to treatment, the CAPS assessment enables clinicians to make a current (past month) diagnosis of PTSD, a lifetime diagnosis, and assess PTSD symptoms over the past week.
There are also basic self-screen tools individuals can use to determine if they should see a physician for a formal diagnosis. The Veterans Administration provides a basic self-screening tool asking individuals to identify if they’ve experienced three or more of the following in the past month
- Nightmares or intrusive thoughts regarding the event
- Avoidance of people, places or things that remind you of event or frequently try not to think about the event
- Always on guard or hyperarousal (easily startled)
- Feel numb or detached from your surroundings or people
- Feelings of guilt or blame for the event
Conventional Treatments: How is PTSD Treated?
Cognitive behavioral therapy which typically lasts at least three months, and is considered one of the most effective forms of treatment. The two most effective types include Prolonged Exposure and Cognitive Processing Therapy:
Prolonged Exposure Therapy (PE): Helps individuals learn to manage memories, situations and feelings avoided since the trauma. The goal is to decrease PTSD symptoms by confronting and dealing with these obstacles.
Cognitive Processing Therapy: A specialized form of cognitive behavioral therapy (CBT) specifically to aid people with PTSD. Patients will typically go through 12 individuals sessions.
Pharmaceuticals: Antipsychotics and antidepressants are often used to treat PTSD. However, some can be ineffective, and in some cases harmful.
Benzodiazepines (like Xanax, Klonopin, Valium) are fairly limited in their utility. They relieve acute anxiety. May help short term, but quickly lose effectiveness and can be highly addictive and often are accompanied with adverse side effects.
Antidepressants (Zoloft, Prozac and Paxil). According to a New York Times summary from the largest study on antipsychotics: "Drugs widely prescribed to treat severe PTSD for veterans are often no more effective than placebos and come with serious side effects.
PTSD and the Body’s Cannabinoid System
The endocannabinoid (eCB) system — our body’s own cannabinoid system — through activation of two receptors (CB1 and CB2) exerts powerful effects on our physical and emotional states. Animal and human studies have shown how PTSD patients have deficiencies in their endocannabinoid system. In fact, brain scans of PTSD patients show a significant reduction in anandamide (a natural cannabinoid produced in the body that acts similarly to THC, also called the “bliss molecule) and an increase in CB1 receptors. (The increase in CB1 receptors is likely the body’s adaptive response to better utilize the less anandamide available.)
Between CB1 and CB2 — the two conclusively identified cannabinoid receptors — CB1 appears to play the most influential role in PTSD:
Decrease in anxiety: Increased levels of “anandamide” — a natural cannabinoid produced in the body that acts similarly to THC (also called the “bliss molecule”) — and enhanced CB1 receptor signaling is associated with a decrease in anxiety and healthy fear memory extinction. Cannabidiol (CBD) appears inhibit activity of an enzyme (FAAH) that is known to degrade 2-AG and anandamide, which could elevate anandamide and 2-AG levels.
Researchers from NYU Langone Medical Center uncovered the relationship between CB1 receptor density (in the brain) and PTSD. flashbacks, nightmares, emotional instability. CB1 receptors play a vital role in memory formation, pain sensory, appetite, and mood. Animal studies have helped us understand how compounds found in cannabis (and naturally occurring chemicals in the endocannabinoid system) activate CB1 receptors to influence memory and reduce anxiety.
Alexander Neumeister who heads the molecular imaging program at NYU School of Medicine used brain imaging to show that individuals suffering from PTSD have significantly lower concentrations of anandamide (an endocannabinoid). "That's a problem. There's a consensus among clinicians that existing pharmaceutical treatments such as antidepressant simply do not work. In fact, we know very well that people with PTSD who use marijuana — a potent cannabinoid — often experience more relief from their symptoms than they do from antidepressants and other psychiatric medications. Clearly, there's a very urgent need to develop novel evidence-based treatments for PTSD."
Their study revealed that those with PTSD (particularly women) had greater CB1 receptor density (19.5% on average) in parts of the brain associated with fear and anxiety than the control group (participants without PTSD), and lower levels of anandamide (58.2% lower on average) which activates CB1 receptors. The reason for the inverse relationship between receptor density and anandamide levels is because, "this helps the brain utilize the remaining endocannabinoids."
How Can Cannabis Help Treat PTSD?
"Cannabis is a [traumatic] memory eraser," reports Michael Krawitz, the head of Veterans for Medical Cannabis Access. "It's been found effective in nightmare cessation, too," explaining how flashbacks are common among vets who’ve seen serious combat, and that
too often patients are opiates or benzodiazepines for PTSD, leaving them "feeling like zombies" and at risk of addiction. In contrast, Krawitz claims cannabis allows them to function normally. While his observations may be based on personal experience, Krawitz and other veterans have an increasing body of evidence supporting them.
Brazilian researchers conducted an animal study (using rodents) of cannabidiol (CBD) — the most prominent non-psychoactive ingredient in cannabis — that supports accumulating evidence that the endocannabinoid system exerts a powerful influence over our emotional state, and that elevating eCB levels can reduce anxiety, while facilitating extinction of fear memories. The authors note given the volume of studies demonstrating CBD's effectiveness, tolerability and favorable safety profile in humans, CBD could play a viable role as a supplement to exposure-based psychotherapies for anxiety disorders like PTSD in which the retention of traumatic memories worsens symptoms.
A 2009 case series published in the Neuroscience and Therapeutics journal, assessed 47 patients who didn't respond to treatment to prevent recurrent nightmares. They were given nabilone (synthetically-derived THC). 28 experienced complete cessation of nightmares. 6 experienced a reduction. 72% of patients experienced improvements. (However, only four out of 32 were able to discontinue use of nabilone without nightmares returning.)
Building on the foundational knowledge established from earlier animal and human studies, an Israeli study (published in 2010) tracked 80 PTSD patients over three years and found most patients who used cannabis experienced an improvement in quality of life and a reduction in pain scores (with no adverse events reported). (Reznik). A 2012 Israeli pilot study of 29 male combat veterans suffering from PTSD receiving smokable cannabis (THC (23%) and CBD (>1%) found on average an approximately 40% reduction in PTSD scores (based on the CAPS assessment).
A study of PTSD patients in New Mexico that also used the CAPS assessment to quantify results, showed patients reported more than a 75% reduction in all three DSM-IV PTSD symptom clusters (reexperiencing the traumatic event; avoidance of cues that reminded them of the event; and, hyperarousal such as sleep disturbances and exaggerated responses to stimuli). While the group was comprised of patients who had previously found cannabis beneficial (increasing risk of study bias), the authors claimed their findings were consistent with significant findings from preclinical studies demonstrating the eCB system's influential role in emotional regulation and memory processing.
With low toxicity (there have been no overdose deaths directly attributed to cannabis consumption), a lower risk of abuse compared to alcohol and many other drugs, and few side effects, the safety profile of cannabis is favorable.
However, it's important to consider that drug and alcohol use disorders are common among those suffering from PTSD, so any patient using cannabis or any other substance should be aware of this elevated risk, and closely monitor their use to ensure therapeutic use doesn’t evolve into misuse or dependency.
Further, we don’t fully understand the potential long-term consequences or risks of using cannabis to treat PTSD. Most studies have been short in duration, so we have little long-term data. However, evidence does suggest that heavy use of cannabis over a long period of time could to down-regulation of CB1 receptors. What does that mean? You would need cannabis to compensate for this deficiency, which increases one’s chances of developing a dependency. Likewise, down-regulation of the CB1 receptor can increase the risk of developing depression.
Ultimately, the decision to treat PTSD with cannabis is a personal one that should be done in consult and supervision of a physician who is knowledgeable about cannabinoid therapies. Further, as a safeguard against becoming too reliant on THC-rich cannabis, patients may want to consider taking periodic breaks (“cannabis holidays”). But, rather than eliminating cannabis completely, one can consider using CBD. CBD, used independently, can be highly useful in treating PTSD and anxiety and while relaxing, doesn’t produce a “high.”
Aupperle, R.L., Melrose, A.J., Stein, M.B. and Paulus, M.P. (2012) ‘Executive function and PTSD: Disengaging from trauma’, Neuropharmacology, 62(2), pp. 686–694. doi: 10.1016/j.neuropharm.2011.02.008.
Berardi, A., Schelling, G. and Campolongo, P. (2016) ‘The endocannabinoid system and post traumatic stress disorder (PTSD): From preclinical findings to innovative therapeutic approaches in clinical settings’,Pharmacological Research, 111, pp. 668–678. doi: 10.1016/j.phrs.2016.07.024.
Betthauser, K., Pilz, J. and Vollmer, L.E. (2015) ‘Use and effects of cannabinoids in military veterans with posttraumatic stress disorder’, American Journal of Health-System Pharmacy, 72(15), pp. 1279–1284. doi: 10.2146/ajhp140523.
de Bitencourt, R.M. (2013) ‘A current overview of cannabinoids and glucocorticoids in facilitating extinction of aversive memories: Potential extinction enhancers’, Neuropharmacology, 64, pp. 389–395. doi: 10.1016/j.neuropharm.2012.05.039.
Bitencourt, R.M., Pamplona, F.A. and Takahashi, R.N. (2008a) ‘Facilitation of contextual fear memory extinction and anti-anxiogenic effects of AM404 and cannabidiol in conditioned rats’, European Neuropsychopharmacology, 18(12), pp. 849–859. doi: 10.1016/j.euroneuro.2008.07.001.
Blessing, E.M., Steenkamp, M.M., Manzanares, J. and Marmar, C.R. (2015) ‘Cannabidiol as a potential treatment for anxiety disorders’, Neurotherapeutics, . doi: 10.1007/s13311-015-0387-1.
Donovan, E. (2010) ‘Propranolol use in the prevention and treatment of Posttraumatic stress disorder in military veterans: Forgetting therapy revisited’, Perspectives in Biology and Medicine, 53(1), pp. 61–74. doi: 10.1353/pbm.0.0140.
Neumeister, Alexander; Daniele Piomelli; et al. "Elevated Brain Cannabinoid CB1 Receptor Availability in Posttraumatic Stress Disorder: A Positron Emission Tomography Study." Molecular Psychiatry. U.S. National Library of Medicine, 14 May 2013. Web. 17 Oct. 2016.
Passie, T. (2012) ‘Mitigation of post-traumatic stress symptoms by Cannabis resin: A review of the clinical and neurobiological evidence’, Drug Testing and Analysis, 4(7-8), pp. 649–659. doi: 10.1002/dta.1377.
Rabinak, Christine A; et al. "Cannabinoid Facilitation of Fear Extinction Memory Recall in Humans." Neuropharmacology. U.S. National Library of Medicine, Jan. 2013. Web. 17 Oct. 2016.
Stern, C.A.J. (2012) ‘On disruption of fear memory by Reconsolidation blockade: Evidence from Cannabidiol treatment’, Neuropsychopharmacology, 37(9), pp. 2132–2142. doi: 10.1038/npp.2012.63.
Stern, C.A.J. (2015) ‘?9-Tetrahydrocannabinol alone and combined with cannabidiol mitigate fear memory through reconsolidation disruption’, European Neuropsychopharmacology, 25(6), pp. 958–965. doi: 10.1016/j.euroneuro.2015.02.001.