Clinical Studies and Case Reports

“Mrs. L” was a 38-year-old woman who was admitted with recurrent major depression and OCD (Yale-Brown Obsessive Compulsive Scale score: 20) after outpatient treatment with paroxetine (60 mg) for 8 months and cognitive behavioral therapy (CBT) were not efficacious. Switching to clomipramine (300 mg) resulted in partial response after 12 weeks of treatment. Based on the patient’s report that smoking marijuana usually relieved her symptoms, an augmentation with dronabinol (2.5%; 10 mg t.i.d.) was started. The prior medication was continued. While undergoing treatment with dronabinol (2.5%), the patient’s OCD symptoms decreased significantly within 10 days (Yale-Brown Obsessive Compulsive Scale score: 10).

“Mr. K” was a 36-year-old man with schizophrenia and OCD who was admitted for deterioration of psychotic and obsessive symptoms (Yale-Brown Obsessive Compulsive Scale score: 23). During his course of illness, Mr. K had been treated with antipsychotics (including haloperidol, olanzapine, risperidone, quetiapine, and aripiprazole), both in monotherapy and in combination with selective serotonin reuptake inhibitors. His OCD symptoms in particular remained predominately treatment resistant. Treatment with clozapine (400 mg), which he had already received for more than 1 year (in combination with paroxetine [60 mg] for 13 weeks) resulted only in partial response of his psychotic and OCD symptoms. Switching paroxetine to clomipramine (for another 10 weeks), followed by an additional course of 18 electroconvulsive therapy treatments (right unilateral high dose), did not improve the patient’s psychotic or OCD symptoms significantly. After the addition of dronabinol to ongoing treatment with clomipramine (150 mg) and clozapine (400 mg), a significant reduction of OCD symptoms was observed within 2 weeks (Yale-Brown Obsessive Compulsive Scale score: 15). In order to prevent psychotic deterioration, dronabinol (2.5%) was carefully increased to 10 mg b.i.d.

Apart from anticholinergic symptoms that preceded the addition of dronabinol (patient 1: dry mouth, constipation; patient 2: constipation, hypotension), both patients reported no side effects. In particular, there was no deterioration of psychotic or mood disorder symptoms.