Understanding variability is crucial for any psychiatric intervention. This is especially true when it comes to treating post-traumatic stress disorder (PTSD), which encompasses a wide array of people and circumstances, and is often a chronic condition – particularly when not treated within the first year.

“If a clinician doesn’t understand the chemistry, biology, and emotional variability of an individual with PTSD, intervention will not work,” said Roger A. Clemens, DrPH, associate director of the regulatory science program at USC’s School of Pharmacy.

Psycom Pro talked to Dr. Clemens and other experts about the growing use of medical marijuana as a PTSD intervention. It’s “a topic that isn’t adequately investigated. We simply don’t have enough information on how to take it, what the differential affects will be for different personality types, and how different products will affect people,” adds Dr. Clemens, who is also a US Veteran.

But there are ways to approach use of the substance in mental health care despite the lack of research, regulation, or consensus. Here, we walk you through how to talk about cannabis as a treatment if, or rather, when your patients with PTSD ask. The focus of this article will be on how cannabis can help to attenuate symptoms of anxiety, sleep disturbance, recurrent fear memories, and panic episodes.

We will also discuss when medicinal marijuana should not be recommended (heads up: in cases of psychoses or schizophrenia) as well as possible complications, differences in strains, and administrative routes.

Patient Identification for Medical Marijuana Use

As psychiatrists know, PTSD is often wrought with complications, resulting from a variety of traumatic stressors that are interpreted by the subjective experience of the individual.1 Each patient may respond to treatment differently. Thus, when weighing medicinal marijuana use for individuals with PTSD, it is important to consider the following points.

The chemistry of the product – The most studied cannabinoids in marijuana are tetrahydrocannabinol (THC) and cannabidiol (CBD). Both compounds interact with the endogenous cannabinoid system, however, THC directly attaches to CB1 and CB2 receptors and has a psychotropic effect. CBD acts on the endogenous cannabinoid system by indirect means, although some studies suggest possible allosteric binding on C1 receptors that may modulate the psychotropic effects of THC. 2 CBD does not produce the same “high” as THC, is generally regarded as non-addictive, and has a low side effect profile.

 The workings of the endocannabinoid system – Research to date suggests that CBD indirectly affects the endocannabinoid system by inhibiting the uptake or enzymatic degradation of the endogenous cannabinoids, AEA and 2-AG, allowing them to have a greater effect on the CB1 and CB2 receptors. CB1 receptors are primarily found in the central and peripheral nervous systems, particularly in the central regions known to play important roles in anxiety and aversive learning, such as the amygdala, hippocampus, and cerebral cortex.3 Studies have shown that some patients with PTSD have decreased peripheral levels of AEA, and increased levels of cannabinoid receptors, suggesting an AEA deficiency. CBD may help to rebalance a person’s endogenous cannabinoid response, thereby easing symptoms of PTSD, such as recurrent fear memories and anxiety.4

While CBD in medicinal marijuana indirectly acts on the endocannabinoid system, it also acts on additional biological pathways that play important roles in the modulation of anxiety, memory, and sleep.

The symptoms of the patient – PTSD is often grouped into categories of avoidance, intrusion, and alterations in cognition and mood,5 but it is crucial to discuss and understand the specific symptoms of each patient. While many individuals with PTSD exhibit anxiety,6 for instance, others may experience depression, phobias, and dissociation. Your patient’s profile can help to determine if medicinal marijuana will be a useful tool for them.

Here are a few quick rules for thought (more details on the data below):

  • Medicinal marijuana with a high CBD to low THC ratio may decrease feelings of anxiety and may help patients who are having trouble falling or staying asleep.7-8,12,13
  • For patients with daytime delusions, medicinal marijuana may not be useful, unless a high CBD strain is being used to reduce the anxiety associated with these symptoms.
  • Medicinal marijuana is not advised for patients with a history of schizophrenia, or with a familial history of schizophrenia, as the THC may precipitate episodes of schizophrenia and mood alterations.14,15
  • In all cases, a high THC strain should never be advised as it may induce paranoia in an already at-risk population.14,15

The patient’s history – Prior and cumulative effects of trauma are particularly important risk factors for chronic PTSD. A patient who has experienced previous trauma may react differently than a patient who experiences a first-time traumatic event.

The type of trauma experienced is also important. The most common precipitating events of PTSD in men are violence and loss associated with combat, whereas the most common precipitating events for PTSD in women are sexual assault.11 Understanding the precipitating trauma can help clinicians to best utilize medicinal marijuana as a tool.

As an example, if a rape survivor cannot ride the train alone because of anxiety caused by the rape event, recommending CBD to decrease her anxiety while also facilitating CBT may prove more useful than recommending CBD alone.

In the case of a returning Veteran, CBD may be recommended as an anticipatory treatment if the individual is expected to encounter potentially triggering loud noises, crowds, or other scenarios that promote panic. In this situation, CBD may help the patient to remain involved with activities and friends that can ease the isolation of PTSD.

As noted above, whether or not a person has a history of psychoses, including as a result of schizophrenia or bipolar disorder, is also an important factor when considering recommending medicinal marijuana.

 Concurrent therapies – Medicinal marijuana is best used as an ancillary or complementary treatment and should not be considered a blanket solution for PTSD. As is true with other psychiatric disorders, treating PTSD requires a combination of therapeutic tools. Counseling with a provider who is knowledgeable and experienced in the specific needs of a person with PTSD should be part of any treatment plan.

What the Data Show Regarding PTSD Symptom Alleviation with CBD

Anxiety – When it comes to PTSD-related anxiety, data shows that CBD can help to ease symptoms by modulating the serotonin pathway.16 In animal models, CBD acted similarly to a SSRI. In human models, a recent small clinical trial used the Fear of Negative Evaluation Questionnaire and the Liebowitz Social Anxiety Scale to access the effects of CBD oil on teenagers with social anxiety disorder and avoidant personality disorder. 17 The 37-person study was conducted on 18- and 19-year-old teenagers in Japan. Each day for 4 weeks, the experimental group was administered a 300-mg dose of CBD hemp oil, whereas the control group was given a placebo. At the end of the 4 weeks, scores of patients in the experimental group were lower compared to baseline on the Fear and Liebowitz scales, indicating that the CBD helped to lower their feelings of anxiety. No negative health outcomes were reported.

Averse Memories – CBD may help to reduce averse memories in people with PTSD. Functional neuroimaging studies in patients with PTSD suggest that the amygdala and dorsal anterior cingulate are hyper-reactive, whereas the ventral medial prefrontal cortex is hyporeactive; abnormalities in brain functioning that may underlie the attentional bias toward threat, impaired emotional regulation, and persistence of fear memories.7

Disordered Sleep – CBD may help a person to fall asleep and to stay asleep, both commonly reported problems in individuals with PTSD.5,18

Additional Clinical Considerations: How Might Medicinal Marijuana Help or Harm a Patient with PTSD?

Peter Pressman, MD, MS, FACN, is director of medical operations at The Daedalus Foundation, a nonprofit that focuses on humanitarian, poverty, and disaster recovery. He is also a US Veteran. Dr. Pressman describes the difficult paradox of recommending medicinal marijuana to patients as follows: “You have to remember the Hippocratic Oath, ‘Do no harm,’ but also, as Paracelsus said, ‘Medicine is not only a science; it is also an art.’”

Dr. Pressman clarified that if medicinal marijuana can help someone to engage in other therapies with a trained professional, it could be a good thing. At the same time, “There’s a real hazard because of the variability of the product. These compounds can actually precipitate psychiatric breakdown in patients with vulnerabilities.”

First, let’s tackle the potential for precipitating a psychiatric event. We spoke with Rachna Patel, MD, who runs CBD consultations in the Bay area and has studied CBD for several years, to better understand the risks and rewards of CBD for PTSD.

“When discussing medicinal marijuana, we are really talking about the two major compounds, CBD and THC,” said Dr. Patel. “Too much THC can cause psychosis because of its interaction with CB1 receptors in the central nervous system.” What equates to “too much” depends on the patient, but is roughly 10 to 15 milligrams. People who already suffer from or have a history of psychoses are considered to be more vulnerable to a negative reaction. “CBD, on the other hand, can help to mitigate the psychosis effects of THC.” (More on the use of medical marijuana in patients with schizophrenia.)

Remember, when recommending medicinal marijuana for the relief of PTSD symptoms, it is the CBD that is beneficial and the THC that can be potentially harmful. Dr. Patel never recommends medicinal marijuana with a high concentration of THC because it has the potential to exacerbate a patient’s anxiety and can induce paranoia.

Second, clinicians are urged to take caution when treating patients with comorbid depression and/or substance abuse history. Dr. Patel does not recommend CBD for the treatment of depression and emphasizes that medicinal marijuana should not be used in place of a person’s current medications for depression. (See also, the use of botulinum toxin for depression.)

Although data to date has shown that CBD is not physically addictive – the jury is still out. Patients who are exhibiting signs of substance abuse or have a history of substance abuse should be monitored carefully, as there may be a higher likelihood to develop a habitual dependence on medicinal marijuana that may become recreational.

You’re Ready to Recommend CBD for your PTSD Patient: But How, What, and How Much?

Dr. Patel works with a variety of patients and products. She recommends that clinicians keep the following in mind when making specific treatment decisions.

 Decide on hemp-based or marijuana-based CBD – Hemp is a species of the marijuana sativa plant that legally has no greater than a 0.3% THC concentration. Many patients who are concerned with a THC profile prefer hemp-based products. There is, however, a caveat. Hemp-based CBD products (while federally legal) are unregulated and may contain higher amounts of THC than listed, lower amounts of CBD, heavy metals, microbial contaminants, and pesticides. For this reason, Dr. Patel advises that clinicians recommend marijuana-based CBD – if they reside in a state where medicinal marijuana is legal. The product is likely to be more reliable, higher quality, and can still have an extremely low THC concentration. She recommends that there is at least 20 to 30 times the amount of CBD to THC in any given ratio of a product.

Ask for third-party testing –  If recommending a hemp-based CBD product, it is always best to insist on third-party testing. To get these test results, you can ask the company providing the product, or use a company that publishes these results online. You can also enlist your own third-party testing by consulting a laboratory (the USDA provides a searchable hemp testing laboratory list).

CBD is fat-soluble – so many people will not need to take it every day.

 Be clear on what you are treating – CBD will not “cure” PTSD but it may help to relieve symptoms and make it easier for a person to continue with therapy and engage in relationships and activities. CBD can also likely help a patient who is suffering from anxiety, panic episodes, and disordered sleep as a result of their PTSD.

Patient administration of the CBD – How a person takes CBD will modulate its effects. If the product is being used preventatively, a tincture may be used. “Tinctures are more measurable and typically take 1 to 2 hours to take effect,” said Dr. Patel. “If the product is being used abortively, patients might do better with a sublingual spray, because it will have an immediate effect. Some patients may be able to take CBD only as needed, rather than relying on a daily dose as they might with an SSRI.”

Are there contraindications? Take caution when working with patients on blood-thinners (eg, heparin, warfarin, ibuprofen) as CBD can ramp up the blood-thinning effect.


Overall, medicinal marijuana can be a useful adjunct for some patients with post-traumatic stress disorder, particularly when anxiety is a key symptom and the patient wants help without the side effects of traditional pharmaceuticals. If medicinal marijuana allows an individual to engage in other meaningful therapies such as CBT, talk therapy, or group counseling, it can be a beneficial part of their individualized yet comprehensive treatment plan.

Update: See new research from Bonn-Miller et al in PLOS ONE, on cannabis and PTSD symptoms from a randomized cross-over trial

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Last Updated: Jun 16, 2021