Good M I
Am J Psychiatry. 1981 Aug;138(8):1112-3. doi: 10.1176/ajp.138.8.1112.
The author describes the case of a patient who received neuroleptics and antiparkinsonian medications for more than 7 years and whose tardive dyskinesia symptoms disappeared after trihexyphenidyl was discontinued. The case appears to support the hypothesis that there is a threshold effect of antiparkinsonian agents on tardive dyskinesia.