Reduced benzodiazepine sensitivity in patients with panic disorder: comparison with patients with obsessive-compulsive disorder and normal subjects.
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.


METHODS
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.
Department of Psychiatry, Tufts University, Boston, USA. roybyrne@u.Washington.edu
P
P
Roy-Byrne
D K
DK
Wingerson
A
A
Radant
D J
DJ
Greenblatt
D S
DS
Cowley
D000328:Adult; D014151:Anti-Anxiety Agents / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use*; D001143:Arousal / Q000187:drug effects; D003975:Diazepam / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D009771:Obsessive-Compulsive Disorder / Q000188:drug therapy* / Q000523:psychology; D016584:Panic Disorder / Q000188:drug therapy* / Q000523:psychology; D012438:Saccades / Q000187:drug effects*; D012890:Sleep / Q000187:drug effects; D016896:Treatment Outcome
D014151:Anti-Anxiety Agents; D003975:Diazepam