Pupillary constriction during haloperidol treatment as a predictor of relapse following drug withdrawal in schizophrenic patients.

It has been proposed that the autonomic nervous system is dysregulated in schizophrenia. We hypothesized that measures of autonomic function, even during neuroleptic stabilization, might predict relapse following withdrawal of medication. Previously, shorter latencies to maximum pupillary constriction have been reported to differentiate acutely hospitalized schizophrenic patients from control subjects. Pupillary light reactions were recorded weekly from 19 chronic schizophrenic inpatients who were initially maintained on haloperidol and subsequently were withdrawn from medication under double-blind, placebo-controlled conditions. Patients were then classified as either relapsed or nonrelapsed (clinically stable) during the drug-free period. During the treatment phase, a shorter latency to maximum pupillary constriction significantly distinguished patients who were later to relapse from the nonrelapsers. The potential use of autonomic activity as an indicator of prodromal sensitivity was supported. In addition, these findings emphasize the need for classification of drug-free patients according to clinical status.