Research on the use of cannabidiol for psychotic symptoms in people with schizophrenia is conflicting. Some early research suggests that taking cannabidiol four times daily for 4 weeks improves psychotic symptoms and might be as effective as the antipsychotic medication amisulpride. Herbal Wiz CBD Oil The researchers also found that subjects were not likely to build up a tolerance to the effects of CBD, so they would not need to increase their dose continually. A separate study in the Journal of Experimental Medicine supports these results.