Blink rate is associated with drug-induced parkinsonism in patients with severe mental illness, but does not meet requirements to serve as a clinical test: the Curacao extrapyramidal syndromes study XIII.
Charlotte L MentzelP Roberto BakkerJim van OsMarjan DrukkerGlenn E MatroosMarina A J TijssenPeter N van HartenPublished in: Journal of negative results in biomedicine (2017)
The study was started over 20 years ago in 1992, at the time registering a trial was not common practice, therefore the study was never registered.