title: Cocaine craving, euphoria, and self-administration: a preliminary study of the effect of catecholamine precursor depletion.
abstract: The authors used the acute phenylalanine-tyrosine depletion (APTD) method to test the effect of transient catecholamine precursor depletion on cocaine craving, euphoria, and self-administration. Eight nondependent, nontreatment-seeking cocaine users self-administered 3 doses of cocaine (0.6, 1.5, 3.0 mg/kg, taken intranasally) following ingestion of (a) a nutritionally balanced amino acid mixture, (b) APTD, and (c) APTD followed by L-dopa/carbidopa (2x100 mg/25 mg). APTD decreased both cue and cocaine-induced drug craving but not euphoria or self-administration. APTD+L-dopa also decreased drug craving, possibly reflecting the ability of L-dopa to transiently decrease dopamine cell firing. Together, these preliminary results suggest that the craving elicited by cocaine and cocaine cues is related to changes in catecholamine neurotransmission. Euphoria and the self-administration of freely available drugs by regular users, in comparison, might be better accounted for by other mechanisms.
authors.affiliation: McGill University, Department of Psychiatry, Montreal, PQ, Canada. marco.leyton@mcgill.ca
authors.forename: Marco
authors.initials: M
authors.lastname: Leyton
authors.forename: Kevin F
authors.initials: KF
authors.lastname: Casey
authors.forename: J Scott
authors.initials: JS
authors.lastname: Delaney
authors.forename: Theodore
authors.initials: T
authors.lastname: Kolivakis
authors.forename: Chawki
authors.initials: C
authors.lastname: Benkelfat
mesh_terms: D000328:Adult; D002395:Catecholamines / Q000172:deficiency* / Q000378:metabolism; D002940:Circadian Rhythm / Q000187:drug effects; D003042:Cocaine / Q000008:administration & dosage* / Q000097:blood; D019970:Cocaine-Related Disorders / Q000188:drug therapy / Q000523:psychology*; D018753:Diet, Protein-Restricted; D015259:Dopamine Agents / Q000627:therapeutic use; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage* / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005059:Euphoria / Q000187:drug effects*; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D010649:Phenylalanine / Q000172:deficiency / Q000378:metabolism; D012646:Self Administration; D013997:Time Factors; D014443:Tyrosine / Q000172:deficiency / Q000378:metabolism
chemical_list: D002395:Catecholamines; D015259:Dopamine Agents; D018765:Dopamine Uptake Inhibitors; D014443:Tyrosine; D007980:Levodopa; D010649:Phenylalanine; D003042:Cocaine