There are at least 113 active chemical compounds in cannabis, the most famous of which is tetrahydrocannabinol, more popularly known as THC. This component is what causes the euphoric, sometimes hallucinogenic high that comes with smoking — and in some cases, it’s been linked to the development of psychosis.

However, a different chemical compound in cannabis has been found to have the opposite effect: cannabidiol, or CBD. In the first placebo-controlled trial of using CBD to treat patients with psychosis, CBD was found to significantly reduce psychotic symptoms. The results were published in early December in the American Journal of Psychiatry and are a hopeful result for the three percent of the world’s population diagnosed with psychotic disorders, many of whom are reluctant to take antipsychotic drugs because of the nasty side effects.

In the study, 88 patients diagnosed with schizophrenia were divided into two groups. One group was treated with 1,000 milligrams of CBD, and the control group received a placebo drug. During the six-week trial, all patients continued to take whatever antipsychotic medication they were already prescribed, and the study’s researchers and the patient’s psychiatrists assessed their symptoms and overall condition over the study period.

CBD does not have the same intoxicating effects as THC.

At the end of the trial, the researchers, led by Philip McGuire, Ph.D., a professor of psychiatry at King’s College London, found that patients in the CBD group were more likely to be rated as improved by their psychiatrists, and they reported lower levels of positive psychotic symptoms to the researchers.

“While it is still unclear exactly how CBD works, we know that it acts in a different way to antipsychotic medication, so it could represent a new class of treatment,” McGuire wrote in an article for the Conversation. “The absence of side effects is also potentially important, as a key problem in caring for patients with psychosis is that they are often reluctant to take antipsychotic drugs because of concerns about side effects.”

McGuire says the next step for this research is to carry out another trial with a larger group of people, including patients who have psychiatric disorders other than schizophrenia.

This study adds to the growing body of work which has found that CBD may be a helpful health aide, especially as a treatment for paranoia and anxiety.