Affiliation:
1. Delta-Ziekenhuis (Rotterdam Mental Hospital), Poortugaal, The Netherlands.
Abstract
This study is concerned with the relationship between sedation threshold and autonomic measures in two groups — depressive patients and those suffering from chronic schizophrenia. The sedation threshold was determined according to Shagass' method. In addition, autonomic activity (heart rate, palmar conductance and respiration rate) was simultaneously recorded. There was no evidence of a significant relationship between sedation threshold and autonomic measures. No significant difference in autonomic activity was found between the two groups. Individual differences were shown by each subject having his own idiosyncratic pattern of autonomic activity, regardless of the diagnosis. Consistency of this pattern was found in a substantial proportion of each group. The overall autonomic effect of sodium amytal was insignificant. In particular, the three autonomic measures failed to differentiate between the conditions of rest and sedation, and it was concluded that the sedative influence of sodium amytal is not exerted through a direct action on the autonomic centres. It was suggested that the experimental design would be suitable for comparing the action of sedative and anxiolytic drugs.