In a new review study, researchers examined evidence that suggests the endocannabinoid system (ECS) may play a role in helping relieve symptoms of obsessive-compulsive disorder (OCD) and other similar conditions.
OCD is a complex psychological condition in which patients have uncontrollable, recurring thoughts (obsessions) and behaviors (compulsions) and the urge to repeat actions over and over. In the United States, 2% to 3% of the adult population and according to a study published in May 2015 in the Archives of Disease in Childhood, up to an estimated 4% of children and adolescents have OCD.
The condition is difficult to treat. According to the International OCD Foundation, the most effective treatment is cognitive behavior therapy (CBT) combined with psychiatric medications such as antidepressants and anti-anxiety remedies. Only about 10% recover completely from OCD and just half improve with treatment, noted a Harvard Medical School publication in March 2009.
The study, “The Endocannabinoid System: A New Treatment Target for Obsessive Compulsive Disorder?” noted that there is a growing body of research showing the ECS plays a role in anxiety, fear, and repetitive behaviors.
The ECS is involved in regulating our neurotransmitters, the chemical messengers that carry signals between our nerve cells and other cells in the body, and affects just about all of our physical and psychological functions.
“The research we reviewed in our article indicates that cannabinoids could one day play a role in the treatment of OCD and related disorders,” said lead author and psychiatrist Dr. Reilly Kayser of Columbia University/New York State Psychiatric Institute (NYSPI).
“We examined the complex workings of the ECS and found evidence from animal and human studies supporting a link between OCD symptoms and the ECS,” Kayser said.
NYSPI and Weill Cornell Medical College in New York performed the study, which noted: “[S]ome patients with OCD who smoke cannabis anecdotally report that it relieves their symptoms and mitigates anxiety, and several case reports describe patients whose OCD symptoms improved after they were treated with cannabinoids.”
In a pilot study analyzed by the team, 16 severe OCD patients who underwent therapy and received nabilone — a synthetic form of THC that acts on the brain's ECS -- had nearly twice the reduction in symptoms after four weeks compared with their counterparts who received nabilone alone, or those who received cognitive therapy alone.
Kayser explained that nabilone works similarly to THC but does not have all of the chemical components of cannabis.
He noted that animal models and human imaging studies have suggested that cannabinoids can also enhance fear extinction learning, which involves creating a response that counters the fear response.
“People who have fears — like flying, PTSD [post-traumatic stress disorder], or OCD — have problems with fear extinction learning,” Kayser told Weedmaps News. “We know that CB1 receptor can boost that form of learning and help alleviate those fears.”
As the cannabinoid-1 receptor (CB1) is found throughout the body's entire central nervous system, Kayser explained that there are high concentrations in regions of the brain that are implicated in OCD.
“This is not direct evidence that the endocannabinoid system (ECS) is involved in the pathology that underlies OCD, but is one clue which suggests that such a link may exist,” he said.
Research so Far
Kayser reiterated that there is an urgent need for new treatments as current medications are ineffective for many people.
“Fortunately, there have recently been a number of promising developments that researchers are actively pursuing,” Kayser said, “but at our site, we are continuing to study how cannabinoids impact OCD symptoms.”
Because research has shown that medical cannabis oil is effective in treating other neurological conditions, including reducing epileptic seizures and treating autism symptoms, scientists are broadening their look into the role of the ECS in a variety of conditions.
“OCD is a complex condition that shares features with other illnesses,” Kayser said. “Thus, we looked into studies that explored the role of the ECS in these related conditions as well.”
Dr. Daniele Piomelli, Ph.D., director of the University of California, Irvine, Center for the Study of Cannabis, said the ECS may help regulate psychiatric conditions and provide therapeutic benefits — and his institute aims to prove it.
“Our growing understanding of the ECS confirms the extraordinary interest of this signaling system in the control of many brain functions and in the regulation of human behavior in health and disease,” Piomelli said in an email.
“After a long absence, we are seeing a rebirth of pharmaceutical interest in the therapeutic potential of this system,” said Piomelli, who is the Editor in Chief of Cannabis and Cannabinoid Research in which the review article was published on June 14, 2019.
“This review article offers a critical assessment of the evidence, focused on obsessive-compulsive disorder, and clues to future research,” Piomelli added. “I am optimistic that important advances will take place in the near future.”
The Bottom Line
Which cannabinoid agents to test and how to measure their effects will be among the important questions to consider in designing future studies.
“We need to do well-designed, placebo-controlled studies in humans to help us understand more about how cannabis and related substances impact symptoms of OCD and other psychiatric conditions,” Kayser said.
“At the moment, we have the results from two studies that are currently under review and will hopefully be published in the next few months, so stay tuned.”