Am J Psychiatry 1992; 149:202-206
Copyright © 1992 by American Psychiatric Association
Controlled investigation of the amobarbital interview for catatonic mutism [published erratum appears in Am J Psychiatry 1992 May;149(5):720]
WV McCall, FE Shelp and WM McDonald
Department of Psychiatry, Duke University School of Medicine, Durham, N.C.
OBJECTIVE: Clinical reports over the last 60 years suggest that the
amobarbital interview is effective in relieving catatonic symptoms. This
has never been substantiated with methodologically sound trials. The
authors postulated that a randomized blind comparison of intravenous
amobarbital and saline would demonstrate the superiority of amobarbital in
relieving catatonic mutism. METHOD: The subjects were 20 inpatients with
catatonic mutism. They were randomly assigned to either saline (N = 10) or
a 5% amobarbital solution (N = 10), and the infusions were administered
intravenously at a rate of 1 cc/min or less over 10 minutes by a blinded
physician. A second blinded physician administered a semistructured
interview during the infusion to control for the effect of suggestion. A
third blinded physician rated patient responsiveness, reactivity, and
arousal. Any patient who was unresponsive to the initial infusion was
crossed over to the other infusion. Interviews were videotaped for
determination of interrater reliability. RESULTS: In the initial infusions,
six of 10 patients responded to amobarbital and zero of 10 responded to
saline. Four of the saline nonresponders responded when given amobarbital.
Response was evident by the 4th minute of the amobarbital infusion.
Interrater reliability was high. The responders and nonresponders differed
significantly in the variance of the weight-adjusted amobarbital dose, and
the responders tended to be older and female. CONCLUSIONS: Intravenous
amobarbital is superior to saline in relieving catatonic mutism, although
only 50% of these patients responded. The nonresponders were distinguished
from the responders by a greater variance in the weight-adjusted dose of
amobarbital.
