The effect of chlorpromazine upon psychophysiological, endocrine and information processing measures in schizophrenia

Abstract

schizophrenic patients provided evidence of electrodermal hyper- or hypo-responding to simple stimuli.l-3 Also bilateral asymmetries in electrodermal orienting responses were found with reduced activity on the left hand and increased activity on the right hand.z-4 Neurophysiological evidence shows important modulatory influences on the electrodermal orienting response from the limbic forebrain. 5-7 Systems associated with the amygdala determine whether or not the response occurs, and systems associated with the hippocampus influence the habituation of the orienting response. AS efferent influences from the amygdala are mediated ipsilaterally and hippocampal influences contralaterally,+I the psychophysiological evidence supports the neurophysiological model of central disturbance in schizophrenia. The hyper- and hypo-responsive autonomic arousal patterns were found in approximately equal numbers and some patients changed from one extreme to the other. The following evidence appears to indicate two unitary arousal states in schizophrenia.8 Patients with orienting responses (responders) showed evidence of higher levels of psychophysiological activity and behavioural arousal than those without orienting responses (non-responders). Psychophysiological measures included spontaneous fluctuations and resting or tonic levels of skin conductance, heart rate levels and variability, systolic blood pressure and finger skin temperature.‘-3*9,10 Differences between responders and non-responders were also f0ur.d with a perceptual measure (the two-flash threshold) which correlated positively with electrographic measures of cortical arousal. Responders had keener perceptual resolution than nonresponders.11,‘~ Clinical differences were revealed with nurses’ ratings of psychotic belligerence, manic state, assaultive behaviour, anxiety and attention demanding behaviour. 13 Careful analysis of the heart rate orienting response showed changes which parallelled those in skin conductance. The form of the second component of the heart rate response was either acceleration or deceleration in responders, and essentially no change in non-responders.10 ln a multivariate analysis of psychophysiological variables levels of activity were sufficient in themselves to predict responding status.*,14 The evidence of two bipolar states of arousal in schizophrenic patients was important in view of evidence of LACEY and colleagues that in the normally functioning organism such