SEROTONIN FUNCTION IN PANIC DISORDER - INTRAVENOUS ADMINISTRATION OF META-CHLOROPHENYLPIPERAZINE

A placebo-controlled study of the direct serotonin receptor agonist me ta-chlorophenylpiperazine (MCPP), intravenously infused over 90 s in a 0.06 mg/kg dose, was conducted in 10 patients with panic disorder and 9 normal control subjects. Cortisol, MCPP serum levels, and behaviora l responses were measured over a 180-min period. MCPP induced equivale nt cortisol release and behavioral responses in both groups. Differenc es between intravenous and oral administration of MCPP are discussed, and the present findings are related to the serotonergic hypothesis of panic disorder.