• We studied the action of cholecystokinin tetrapeptide (CCK-4) in patients with panic disorder and normal controls. Subjects received, in random order, one injection of CCK-4 and one injection of placebo (saline) on two separate days in a double-blind crossover design. Two doses of CCK-4, 50 and 25 μg, were administered to two different samples of subjects. The panic rate with 50 μg of CCK-4 was 100% (12/12) for patients and 47% (7/15) for controls. The panic rate with 25 μg of CCK-4 was 91% (10/11) for patients and 17% (2/12) for controls. Nine percent of patients compared with 0% of controls panicked with placebo. These findings concur with previous reports of a panicogenic effect of CCK-4 and suggest that patients with panic disorder are more sensitive to the panicogenic effect of the peptide than are normal controls.
Bradwejn J, Koszycki D, Shriqui C. Enhanced Sensitivity to Cholecystokinin Tetrapeptide in Panic DisorderClinical and Behavioral Findings. Arch Gen Psychiatry. 1991;48(7):603-610. doi:10.1001/archpsyc.1991.01810310021005