The physiological and psychological effects of intravenously administered epinephrine and its metabolism in normal and schizophrenic men—II.: Psychiatric observations

Abstract

Twelve “normal control” volunteers and twelve chronic schizophrenic patients received intravenous of isotopically labelled epinephrine in a complex experimental situation permitting simultaneous study of multiple biological and psychological variables. The major psychological changes accompanying epinephrine infusion were: (a) increased arousal, (b) narrowing of the field of attention, (c) change of direction of attention toward inner body experience, (d) resultant difficulty in communication and concentration and (e) subjective feelings of anxiety. Some “normal control” volunteer subjects distinguished these anxiety feelings from actual life-situation anxiety. There was no qualitative difference in the psychological response of the schizophrenic and the “normal control” groups to epinephrine infusion. In neither “normal control” volunteers, nor schizophrenic patients, did epinephrine cause the appearance or exacerbation of psychotic symptoms. There were two instances of increase of psychotic behavior during or after the epinephrine infusion in schizophrenic patients, but these could not be attributed to the epinephine per se; and seemed more clearly related to situational variables. This result fails to support hypotheses which attribute the origin of schizophrenic symptoms to an abnormality in the metabolism of epinephrine. Quantitative differences between the schizophrenic and “normal control” subjects showed that, as a group, the schizophrenic subjects were much less able to cope with the experimental situation (p = <0·002), showed more anxiety in response to the situation (p = <0·02) but less in response to epinephrine (p = <0·02), and ranked lower on involvement-communication (p = <0·02). It is believed that a major factor in the smaller anxiety response during epinephrine infusion in the schizophrenic patient group, compared to the “normal control” group, was its higher situational anxiety baseline. Differences between schizophrenic and “normal control” subjects in their ability to cope with an experimental situation, and in their resultant situational anxiety, are judged to be widely prevalent in research studies comparing schizophrenic and “normal control” subjects. Such differences must be given careful consideration before concluding that a particular hypothesis being investigated has or has not been validated.