Three New Studies on Cannabis and PTSD, Nate Seltenrich, 2022

Growing numbers of trauma sufferers are medicating with cannabis and finding it helpful.
31 décembre 2022

In recent years, psilocybin and MDMA have been explored as potential treatments for post-traumatic stress disorder, but somewhat more quietly so has cannabis. In fact, according to a few quick searches of PubMed, cannabis has a longer and richer association with PTSD in the scientific literature than any psychedelic. Though you wouldn’t know that by reading the headlines.

Setting aside for a minute how effective psychedelics may or may not be as breakthrough treatments for PTSD, there’s no doubt that cannabis is still much easier for most patients to access.

Recent research – including three new studies (from three different countries) – suggests that growing numbers of PTSD sufferers are medicating with cannabis, and truly finding it helpful.


First, a paper in the journal BMC Psychiatry from researchers based in Ontario, Canada, provides some insight into cannabis use among PTSD patients during the first wave of the coronavirus pandemic. Between April 3 and June 24 of 2020, 462 individuals with self-reported PTSD completed an online questionnaire that assessed mental health symptoms and cannabis intake both before the pandemic and in the seven days prior to filling out the survey.

Stress, anxiety, and depression worsened across the board, but by categorizing participants according to cannabis use patterns – not using, using less, using the same, or using more – the researchers discovered something interesting. PTSD sufferers who increased their cannabis use during the pandemic were more likely to also experience “meaningful perceived worsening of depression symptoms,” the authors write.

Does this mean that cannabis exacerbated depression? It’s theoretically possible, given that the study does not address causality. However, much more likely given what previous research has shown about the relationship between cannabis and depression is that it went the other way: worsening depression led to greater cannabis use. In other words, these individuals were likely suffering during the pandemic and using cannabis to make themselves feel better.

The extent to which cannabis actually helped, if at all, is beyond the scope of this research – but another recent study with a slightly different design tackles that question more directly.


In the UK, individuals diagnosed with PTSD can be prescribed medical cannabis. Yet a paucity of clinical evidence limits its use, write the London-based authors of a December 2022 paper in the journal Expert Review of Neurotherapeutics.

So they designed a study that would use patient responses to validated questionnaires to measure changes in sleep quality, anxiety, and PTSD-specific symptoms (intrusions, avoidance, and hyperarousal) over time.By comparing scores from 144 PTSD patients at baseline and one, three, and six months after initiating medical cannabis use, the researchers observed significant improvements in all three categories across all follow-up periods. Adverse events related to cannabis use were predominately mild or moderate, with insomnia and fatigue being most common at 20 incidents each.

This study also has numerous limitations. It is observational in nature, leaving many variables uncontrolled and others, including dose size and frequency, reliant on participant reporting. In addition, all outcome measures are subjective.

“Nevertheless, this study can serve to inform future randomized placebo-controlled trials with the aim of confirming these promising effects, whilst informing current clinical practice,” the authors write. “Future work should also focus on including objective measures, determining optimal dosages, and conducting comparisons to existing treatments to better inform prescribing of add-on or sole [medical cannabis] therapy.”



Improved sleep quality may be an important mechanism through which cannabis reduces PTSD symptoms during daytime and nighttime alike, posit the Israel-based authors of a paper published in the December 2022 issue of the Journal of Anxiety Disorders.

To learn more about how cannabis use affects sleep, they asked 77 licensed medical cannabis patients suffering from PTSD to report each morning on the timing of cannabis use the previous evening and subsequent sleep disturbances during the night.

Interestingly, the closer to bedtime an individual used cannabis, the less likely they were to experience nightmares – which may in turn translate to reduced daytime stress.

The authors’ analysis also revealed that those who used products with higher CBD concentrations (primarily smoked flower, but not exclusively) reported fewer early awakenings, and thus longer sleep. Number of nightly awakenings, the third outcome variable measured, was not associated with any aspect of cannabis use – though the researchers did find that those who went to bed later reported fewer awakenings.

This is a small study that again lacks controls and relies on self-reporting, yet it adds to a growing body of clinical and preclinical research suggesting beneficial effects of cannabis for post-traumatic stress disorder – in this case via improved sleep. As the authors put it in concluding their own paper, “Given the high comorbidity of PTSD symptoms and sleep disturbances and the potential for medical cannabis to have effects on both, a greater understanding of how patients experience the effects of medical cannabis on overall PTSD symptoms and sleep disturbances is warranted.”

Nate Seltenrich, an independent science journalist based in the San Francisco Bay Area, covers a wide range of subjects including environmental health, neuroscience, and pharmacology. Copyright, Project CBD. May not be reprinted without permission.


  1. Sznitman, Sharon R et al. “Posttraumatic stress disorder, sleep and medical cannabis treatment: A daily diary study.” Journal of anxiety disorders vol. 92 (2022): 102632. doi:10.1016/j.janxdis.2022.102632
  2. Pillai, Manaswini et al. “Assessment of clinical outcomes in patients with post-traumatic stress disorder: analysis from the UK Medical Cannabis Registry.” Expert review of neurotherapeutics, 1-10. 12 Dec. 2022, doi:10.1080/14737175.2022.2155139
  3. Feingold, Daniel, and Aviv Weinstein. “Cannabis and Depression.” Advances in experimental medicine and biology vol. 1264 (2021): 67-80. doi:10.1007/978-3-030-57369-0_5
  4. Murkar, A et al. “Increased cannabis intake during the COVID-19 pandemic is associated with worsening of depression symptoms in people with PTSD.” BMC psychiatry vol. 22,1 554. 17 Aug. 2022, doi:10.1186/s12888-022-04185-7