title: Seasonal variations in prolactin levels in schizophrenia.
abstract: As part of an ongoing longitudinal study of drug-free schizophrenic patients, we serially sampled resting early morning prolactin levels in 10 subjects. In a preliminary analysis, these levels were compared to those found in matched normal control subjects over a 4-year period. Both control and schizophrenic subjects showed a marked annual variation in prolactin levels. Six schizophrenic patients sampled in each quarter of the year showed a significant annual rhythm, with prolactin highest in the spring (March-May). In seven schizophrenic patients and nine controls sampled at two seasons in the year, prolactin was significantly higher in spring-summer (March-August) than in fall-winter (September-February), with no difference between patients and control subjects.
authors.affiliation: Department of Psychiatry, University of Toronto, Mount Sinai Hospital, Ontario, Canada.
authors.forename: P J
authors.initials: PJ
authors.lastname: Brown
authors.forename: J M
authors.initials: JM
authors.lastname: Cleghorn
authors.forename: G M
authors.initials: GM
authors.lastname: Brown
authors.forename: R D
authors.initials: RD
authors.lastname: Kaplan
authors.forename: J
authors.initials: J
authors.lastname: Mitton
authors.forename: H
authors.initials: H
authors.lastname: Szechtman
authors.forename: B
authors.initials: B
authors.lastname: Szechtman
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D011388:Prolactin / Q000097:blood*; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000097:blood*; D012565:Schizophrenic Psychology; D012621:Seasons
chemical_list: D011388:Prolactin