​The administration of oral synthetic THC is associated with improved symptoms of psychosis in patients with refractory schizophrenia, according to the findings of four case reports published in the November issue of the Journal of Clinical Psychiatry.

Investigators at the Rockland Psychiatric Center in Orangeburg, New York, the Columbia University Medical Center, and the New York University School of Medicine assessed the efficacy of oral THC (Dronabinol) on eight patients with refractory psychosis, reports the National Organization for the Reform of Marijuana Laws ( NORML ). The subjects in the trial had a history of symptomatic improvement when using cannabis and had been unresponsive to conventional medical treatments.

Researchers reported significant improvement in four of the eight patients after oral THC treatment. In particular, cannabinoid administration resulted in a significant reduction in subjects’ aggressive tendencies, authors reported.

No patients in the study experienced any significant side effects from THC.

“It appears that a predisposed subset of patients with schizophrenia may actually improve with cannabinoid stimulation,” investigators concluded.

The team had previously reported positive results with oral cannabinoid therapy in four of six patients with chronic refractory schizophrenia.

In March, investigators at Edmundston Regional Hospital in New Brunswick, Canada reported that male patients diagnosed with schizophrenia obtained subjective benefits from inhaling cannabis.