Behavioural effects of rapid intravenous administration of meta-chlorophenylpiperazine in patients with panic disorder and controls.

Oral and intravenous challenge paradigms with the direct 5-HT agonist meta-chlorophenylpiperazine (m-CPP) in panic disorder (PD) have shown only moderate sensitivity or selectivity of the panicogenic effects in PD. However, the results of a study examining the effects of rapid intravenous administration of 0.1 mg/kg of m-CPP in healthy volunteers suggested that this approach may be a more selective and sensitive panicogenic paradigm in PD. We therefore compared the behavioural, neuroendocrine and physiological effects of rapid intravenous administration of 0.1 mg/kg of m-CPP in 10 patients with PD and 10 healthy controls. Panic attacks were significantly more provoked in patients with PD (90%) compared to healthy controls (0%). Effects on the behavioural, but not on the neuroendocrine and physiological parameters, were significantly greater in patients. Our data suggests that the behavioural effects of rapid intravenous administration of 0.1 mg/kg of m-CPP in patients with PD indeed show a unique combination of high sensitivity and selectivity.