Postimperative negative variation and skin conductance response in chronic DSM-III-R schizophrenia.

The hypothesis was tested that there are relationships between schizophrenic negative or deficit symptoms, the skin conductance nonresponding and an elevated amplitude of the postimperative negative variation (PINV). These variables were recorded in 16 chronic schizophrenics and 10 healthy controls. Clinical symptoms were assessed by the Brief Psychiatric Rating Scale, Scale for the Assessment of Negative Symptoms, Frankfurt Complaint Questionnaire 3 and Chapman Questionnaire. In the patient group we found a significantly elevated PINV at Fz. Surprisingly, only one patient was a skin conductance nonresponder. PINV amplitude at Fz and the number of skin conductance responses to habituation were not correlated with negative or deficit symptoms inclding anhedonia. The hypothesis thus had to be rejected.