title: Evidence of a latitudinal gradient in the age at onset of schizophrenia.
abstract: Variation in the age at onset of a multifactorial disease often reflects variation in cause. Here we show a linear latitudinal gradient in the mean age at onset of schizophrenia in 13 northern hemisphere cities, ranging from 25 years old in Cali, Columbia (at 4 degrees north) to 35 years old in Moscow, Russia (at 56 degrees north). To our knowledge, this striking association has not been previously reported. We consider several explanations, including the effects of pathogen stress, natural selection, sexual selection, migration, life-history profiles, or some combination of these factors, and we propose a test of competing causal hypotheses.
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles and the Veterans Affairs Greater Los Angeles Healthcare System, 11301 Wilshire Blvd., Los Angeles, CA 90073, USA. Andrew.Shaner@med.va.gov
authors.forename: Andrew
authors.initials: A
authors.lastname: Shaner
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Miller
authors.forename: Jim
authors.initials: J
authors.lastname: Mintz
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002980:Climate; D004777:Environment; D005260:Female; D005843:Geography; D006801:Humans; D008297:Male; D012559:Schizophrenia / Q000453:epidemiology*