Serotonin function in panic disorder: effect of 1-5-hydroxytryptophan in patients and controls

The responsivity of the serotonergic system to 5-hydroxytryptophan (5-HTP) administration was investigated in seven patients with panic disorder and seven healthy controls. Using cortisol and beta-endorphin as hormonal probes, no evidence was obtained for a dysfunction of the serotonin system in patients. Behaviorally, controls responded differently from patients, in that controls seemed to be more sensitive to 5-HTP. None of the subjects reported an increase in anxiety.