Growing Interest in Cannabinoids for PTSD Yields Mixed Results

In recent years, exogenous cannabinoids – such as tetrahydrocannabinol (THC) and cannabidiol (CBD) – have generated growing buzz for their potential as a treatment for post-traumatic stress disorder (PTSD).

This growing focus on the endogenous cannabinoid system (eCS) stems from research that suggests this system plays a bigger role in the pathophysiology of PTSD than we originally thought. That’s because of its role in managing one’s stress response while maintaining emotional memory and fear extinction.

So far, animal studies have revealed that triggering cannabinoid 1 (CB1) receptors can help manage these fear-related behaviors, tamp down aversive memory retrieval, and boost memory extinction. All of these could help PTSD patients living with dysregulated fear and stress responses.

The World Health Organization’s (WHO) latest estimates suggest that roughly 3.9 of the world’s population “have experienced PTSD at some point in their lives.” Since that works out to nearly 320 million, its no wonder that these people have embraced less conventional promises of relief – such as cannabis. Consider that:

• Roughly 28 percent of lifetime PTSD patients reported cannabis use at some point in the previous year.
• And more than 9 percent of them meet the criteria for cannabis use disorder (CUD).

As more of these individuals turn to cannabis, it’s incumbent on researchers to reevaluate the benefits and risks involved.

Studies Produce Mixed Results

One group of researchers tried to do just that with a systematic review that examined experimental and observational studies on cannabis and cannabinoid use in PTSD patients. The analysis attempted to assess the effects of cannabinoids on overall PTSD symptoms in addition to symptoms within specific PTSD clusters: re-experiencing traumatic events (Cluster B) and hyperarousal (Cluster E).

The investigation covered 14 studies and more than 5,100 participants. Most of these inquiries relied on either longitudinal or retrospective designs. And while some of the research found positive effects of cannabis use on PTSD symptoms, others reported less encouraging outcomes. 

Specifically, five studies found that cannabinoids notably improved PTSD symptoms. For example, one 12-month study discovered that cannabis-using PTSD patients experienced greater reductions in symptom severity.

In another, the oral administration of nabilone, a synthetic cannabinoid, showed significant PTSD symptom reductions in male inmates with mental health conditions.

On the other hand, another pair of studies reported more discouraging results. In one, military personnel with high baseline PTSD symptoms who used cannabis more often saw their symptoms accelerate.

Another found that veterans who started using cannabis boasted higher PTSD symptom severity at follow-up than those who hadn’t.

Three other studies revealed no consequential link between cannabinoids and PTSD symptom severity. This included a randomized controlled trial (RCT) that compared different cannabis strains with diverse THC and CBD levels.

Cannabinoids and Cluster Symptoms

The review also analyzed the cannabinoids’ influence on specific PTSD symptom clusters, including re-experiencing, avoidance, cognition, and hyperarousal.

For re-experiencing symptoms, such as nightmares, two studies suggested that cannabinoid use could tamp them down. Preclinical research suggests that tripping the CB1 receptor can block the recall of negative memories, which could help explain the nightmare relief.

But the evidence on avoidance symptoms (Cluster C) appeared to be inconclusive. The authors conceded that differences in measurement tools across studies might have clouded the results.

The researchers also stumbled onto mixed results in the papers that examined mood and cognition symptoms (Cluster D). Some of the research suggested a possible link between cannabis use and increased suicidal ideation. Other studies failed to find any noteworthy connections.

Finally, for hyperarousal symptoms (Cluster E), the research team uncovered more consistent evidence that cannabis might help patients sleep better. Previous research has shown that cannabinoid activation of CB1 receptors can reduce wakefulness and promote sleep, which could explain these findings.

But this review also found that cannabis use might be tied to increased aggression and violence. And that could be because of the emotional regulation issues found in most PTSD patients.

Cannabis Use Disorder Complicates Things

The review found that people struggling with both PTSD and CUD endured worse outcomes associated with cannabis use. Patients with a CUD diagnosis experienced slower rates of symptom improvement compared to those without CUD. These findings suggest that while cannabis might offer some symptom relief, it still poses risks for some, especially those already predisposed to substance use disorders.

The systematic review underscores the conflicting evidence surrounding the use of cannabinoids in PTSD treatment. That’s why the researchers conclude their review by insisting on a more robust analysis.

The authors added that future researchers might consider different cannabis strains, dosages, and administration methods to provide clearer guidance for clinicians and patients.

Further Reading

Study Finds Brain Network That Could Protect Against PTSD

Psychiatric Disorders and Comorbid Cannabis Use

Can Emotional Dysregulation Help Explain Adolescent PTSD?