NEW YORK (Reuters Health) – The difficult problem of tardive dyskinesia related to antipsychotic therapy responds to treatment with an extract of Ginkgo biloba, according to a Chinese study reported in the Journal of Clinical Psychiatry online September 21.

Dr. Dong-Feng Zhou at Peking University, Beijing, and colleagues point out that tardive dyskinesia remains a serious adverse effect of neuroleptics, even with newer atypical antipsychotic drugs, in susceptible individuals. On the basis of evidence that free radicals may be involved in the pathogenesis of the disorder, the researchers tested the effects of treatment with a standardized extract of Ginkgo biloba leaves, EGb-17, “a potent antioxidant possessing free radical-scavenging activities.”

They randomly assigned 157 patients with schizophrenia and tardive dyskinesia to EGb-17 240 mg/d or placebo and assessed changes in AIMS (Abnormal Involuntary Movement Scale) score after 12 weeks.

The AIMS total score dropped from a mean of 7.03 to 4.90 in the EGb-17 group but remained almost the same in the placebo group, changing from 6.86 to 6.96. The between-group difference was significant at p<0.0001, the team reports. “At the end of treatment, improvement of 30% or more in the AIMS total score was noted in 40 (51.3%) of the 78 patients treated with EGB-17 and 4 (5.1%) of the 79 patients given placebo,” Dr. Zhou and colleagues found. The authors say the results are encouraging and warrant further study. They add, “The potential usefulness of the extract in the treatment of tardive dyskinesia has clinical importance, as it has only rare and transitory side effects in relatively high doses.” Reference:
Extract of Ginkgo biloba Treatment for Tardive Dyskinesia in Schizophrenia: A Randomized, Double-Blind, Placebo-Controlled Trial

J Clin Psychiatry 2010.