Increased blink rates in schizophrenics. Influences of neuroleptics and psychopathology

During a standardized visuomotor task, eye blinking, a possible parameter of central dopaminergic activity, was studied in 18 previously medicated and eight drug-naive schizophrenic in-patients in the acute state and during remission. Whereas schizophrenics executed the visuomotor task with the same precision as age- and sex-matched normal control subjects did, the mean blink rate was increased in both schizophrenic groups. During neuroleptic treatment, the mean blink rate was reduced only in the group of drug-naive patients, but not in the previously neuroleptic treated schizophrenics. This varying blinking activity is discussed with respect to the development of neuroleptic tolerance and influence of psychopathology.