title: Dose-response relationship of levodopa with mood and anxiety in fluctuating Parkinson's disease: a double-blind, placebo-controlled study.
abstract: We investigated the effect of levodopa on mood and anxiety in eight Parkinson's disease patients with motor fluctuations. Each patient received 0.0-, 0.5-, and 1.0-mg/kg/hr levodopa infusions in randomly assigned order under double-blind conditions on consecutive days. Mood elevation and anxiety reduction based on half-hourly patient rating and a corresponding increase in tapping speed occurred with active drug infusion but not placebo infusion. The effects were dose related. The higher-dose infusion rate produced more rapid onset, greater magnitude, and longer duration of response. We conclude that mood and anxiety fluctuations related to levodopa dosing are robust pharmacologic, and not placebo, effects.
authors.affiliation: Department of Psychiatry, Oregon Health Sciences University, Portland 97201, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Maricle
authors.forename: J G
authors.initials: JG
authors.lastname: Nutt
authors.forename: R J
authors.initials: RJ
authors.lastname: Valentine
authors.forename: J H
authors.initials: JH
authors.lastname: Carter
mesh_terms: D000339:Affect / Q000187:drug effects*; D000368:Aged; D001007:Anxiety / Q000503:physiopathology* / Q000523:psychology; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology / Q000523:psychology
chemical_list: D007980:Levodopa