Skin conductance responding in schizophrenic patients with abnormal involuntary movements

The present study tested the hypothesis that neuroleptic treatment modifies the skin conductance response (SCR) to loud tones. Schizophrenic patients with and without drug-induced abnormal involuntary movements were tested before and after drug withdrawal. During the on-drugs session, habituation of SCR correlated with the daily neuroleptic dose, and patients with tardive dyskinesia (TD) showed the fastest habituation of SCR. These findings were interpreted as indicating that SCR is attenuated by neuroleptics present during the examination and that TD patients demonstrate a preferential susceptibility to this effect. Withdrawal of medication resulted in slowing of SCR habituation only in TD patients, following which the entire sample showed a similar rate of habituation. These findings suggest that accelerated SCR habituation is not a stable trait of TD patients.