Reduced benzodiazepine sensitivity in panic disorder.

We evaluated the functional sensitivity of the gamma-aminobutyric acid-benzodiazepine supramolecular complex in 9 patients with panic disorder and 10 psychiatrically healthy control subjects by comparing the effects of four logarithmically increasing doses of intravenous diazepam on saccadic eye movement velocity, memory, and self-rated sedation. Patients with panic disorder were less sensitive than controls to diazepam using eye velocity as the dependent measure. Sedation and memory effects did not distinguish the two groups. These findings suggest that panic disorder is associated with functional subsensitivity of the gamma-aminobutyric acid-benzodiazepine supramolecular complex in brain-stem areas controlling saccadic eye movements.