Related Experiment Video
Updated: May 2, 2026

Intracerebroventricular Treatment with Resiniferatoxin and Pain Tests in Mice
Published on: September 2, 2020
A multicenter, double-blind, randomized, controlled study of patients with treatment-resistant schizophrenia treated
Jun Horiguchi1, Rei Wake1, Kenta Murotani2
1Department of Psychiatry Shimane University School of Medicine Izumo Japan.
Aim:
We conducted a 12-week double-blind, placebo-controlled, multicenter study to evaluate the efficacy and safety of yokukansan in patients with schizophrenia.
Methods:
Patients with schizophrenia resistant to antipsychotics whose Positive and Negative Syndrome Scale (PANSS) scores were stable within five points were enrolled and assigned to the yokukansan or placebo group. Fifty-three of the 61 consenting patients were allocated to the yokukansan (n = 27) and placebo (n = 26) groups.
Results:
The changes in total and positive PANSS scores at 12 weeks were significantly greater in the yokukansan group than in the placebo group. There were no significant changes in other psychiatric symptom rating scores in either group. Adverse reactions were reported in six of 27 patients (22.2%) in the yokukansan group and five of 26 patients (19.2%) in the placebo group, all of which were nonserious.
Conclusion:
Yokukansan is very safe and has clinical potential as a treatment for schizophrenia in combination with Western medicine.
Related Concept Videos
Psychosis: Goals of Pharmacotherapy
Bioavailability Study Design: Single Versus Multiple Dose Studies
Bioavailability Study Design: Healthy Subjects Versus Patients
Drug Therapy
Antianxiety Medications

