Am J Psychiatry 1996; 153:1444-1449
Copyright © 1996 by American Psychiatric Association
Reduced benzodiazepine sensitivity in patients with panic disorder: comparison with patients with obsessive-compulsive disorder and normal subjects
P Roy-Byrne, DK Wingerson, A Radant, DJ Greenblatt and DS Cowley
Department of Psychiatry, Tufts University, Boston, USA. roybyrne@u.Washington.edu
OBJECTIVE: The authors sought to replicate their previous finding of
reduced response to diazepam in patients with panic disorder, to test
whether this effect was specific for panic disorder, and to determine
whether this reduced response was merely an artifact of resistance to
sedation from anxiety-related overarousal. METHOD: The effects of four
increasing intravenous doses of diazepam on saccadic eye movement velocity
and accuracy (the latter being a saccadic variable that is unaffected by
sedation), short-term memory, and self- and observer- rated sedation were
assessed in 18 patients with panic disorder, 15 patients with
obsessive-compulsive disorder, and 14 normal comparison subjects. The
ratios of effect to blood level areas under the curve for both ascending
and descending limbs of the effect/blood level curves were compared for
each variable. RESULTS: Patients with panic disorder showed significantly
less diazepam effect on saccadic velocity and accuracy for the ascending
limb of the blood level curve than comparison subjects. Patients with
obsessive-compulsive disorder showed similar differences from comparison
subjects but only for saccadic velocity. There were no group differences in
diazepam effects on memory and sedation. CONCLUSIONS: Patients with panic
disorder are less sensitive than comparison subjects to diazepam. Although
this difference is not an artifact of resistance to sedation, it may not be
specific for panic disorder but rather may reflect a more nonspecific
aspect of anxiety disorders.
