title: The effect of 5-hydroxytryptophan on cholecystokinin-4-induced panic attacks in healthy volunteers.
abstract: Previous studies suggest a modulatory role of serotonin (5-HT) in experimentally-induced panic attacks. In the current study, we investigated the acute effects of 5-HT precursor l-5-hydroxytryptophan (5-HTP) on the response to panicogenic challenge with cholecystokinin-tetrapeptide (CCK-4) in healthy volunteers. Thirty-two subjects were randomized to receive either 200 mg of 5-HTP or placebo with the CCK-4 challenge following in 90 min in a double-blind, parallel-group design. The results showed a nonsignificant difference between the groups in panic rate (19% after 5-HTP and 44% after placebo, p = 0.13) with a trend for lower intensity of symptoms after 5-HTP (p = 0.08). Further analysis by gender revealed that females in the 5-HTP group had a significantly lower panic rate and intensity of cognitive symptoms whereas, in males, the effect of 5-HTP was limited to lowering the intensity of somatic panic symptoms. Thus, an increased availability of 5-HT may have a gender-dependent protective effect in CCK-4-induced panic.
authors.affiliation: Department of Psychiatry, University of Tartu, Raja, Estonia. eduard.maron@kliinikum.ee
authors.forename: Eduard
authors.initials: E
authors.lastname: Maron
authors.forename: Innar
authors.initials: I
authors.lastname: Tõru
authors.forename: Veiko
authors.initials: V
authors.lastname: Vasar
authors.forename: Jakov
authors.initials: J
authors.lastname: Shlik
mesh_terms: D006916:5-Hydroxytryptophan / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D002214:Capsules; D003072:Cognition Disorders / Q000139:chemically induced / Q000188:drug therapy / Q000517:prevention & control; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006973:Hypertension / Q000139:chemically induced; D007275:Injections, Intravenous; D008297:Male; D016584:Panic Disorder / Q000139:chemically induced* / Q000188:drug therapy / Q000517:prevention & control*; D011569:Psychiatric Status Rating Scales; D012727:Sex Characteristics; D013610:Tachycardia / Q000139:chemically induced; D013758:Tetragastrin / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D013997:Time Factors
chemical_list: D002214:Capsules; D013758:Tetragastrin; D006916:5-Hydroxytryptophan