Obsessive-compulsive disorder (OCD) is a mental disorder in which patients suffer from obsessive-compulsive thoughts or actions. Although patients are aware that this compulsion is excessive, they have to give in to the urge. Depending on the severity of the disorder, the patient’s daily life may be considerably impaired.
The causes have not been definitively clarified. Psychological explanatory models are being discussed, as well as disorders involving neurotransmitter metabolism as risk factors. There is also evidence of the involvement of various other signalling pathways, such as the glutamatergic, dopaminergic or GABAergic system.
OCD: involvement of the endocannabinoid system
Various studies, in particular a small number of animal experiments, suggest that the endocannabinoid system may be involved in the pathophysiology of OCD.
In 2019, researchers from Columbia University published a review on whether the endocannabinoid system could be a new treatment target for OCD. In addition to a comprehensive review of endocannabinoids and phytocannabinoids, the researchers also presented data from different trials.
In two case reports, the researchers said that treatment with dronabinol had positive results in two patients with OCD who were refractory to treatment. Data from a small open-label, uncontrolled trial also showed that the combination of nabilone and psychotherapy was more effective than any treatment on its own.
In summary, the researchers stated the following:
“Is there a place in psychiatry for cannabinoid-based drugs? Studies in animals and humans have shown that the endocannabinoid system is an important emotional regulator. But how can we use this knowledge for therapy? This review article offers a critical evaluation of the evidence focusing on obsessive-compulsive disorders and provides pointers for future research.”
Medical cannabis in the treatment of Tourette’s syndrome
Patients with Tourette’s syndrome suffer from chronic vocal and/or motor tics, often associated with comorbid obsessive-compulsive behaviour. Various studies and clinical trials have shown in the past that patients with Tourette’s syndrome can benefit from treatment with medical cannabis. After taking various cannabis-based medicines (Sativex, medical cannabis flowers), patients reported an improvement in tics.
Recent case report of a patient with OCD
In a case report, a 22-year-old patient was presented suffering from a severe obsessive-compulsive disorder since childhood. The treatment with medical cannabis significantly reduced the symptoms of OCD. His depression also improved, leading to a significant improvement in his quality of life.