title: Seasonal variation of suicide in the city of São Paulo, Brazil, 1996-2010.
abstract: BACKGROUND
  In light of the few reports from intertropical latitudes and their conflicting results, we aimed to replicate and update the investigation of seasonal patterns of suicide occurrences in the city of São Paulo, Brazil.
  
  
  METHODS
  Data relating to male and female suicides were extracted from the Mortality Information Enhancement Program (PRO-AIM), the official health statistics of the municipality of São Paulo. Seasonality was assessed by studying distribution of suicides over time using cosinor analyses.
  
  
  RESULTS
  There were 6,916 registered suicides (76.7% men), with an average of 39.0 ± 7.0 observed suicides per month. For the total sample and for both sexes, cosinor analysis estimated a significant seasonal pattern. For the total sample and for males suicide peaked in November (late spring) with a trough in May-June (late autumn). For females, the estimated peak occurred in January, and the trough in June-July.
  
  
  CONCLUSIONS
  A seasonal pattern of suicides was found for both males and females, peaking in spring/summer and dipping in fall/winter. The scarcity of reports from intertropical latitudes warrants promoting more studies in this area.
authors.affiliation: Health Department of the city of Guarulhos, <location>State of São Paulo, Brazil</location>
authors.forename: Daniel Hideki
authors.initials: DH
authors.lastname: Bando
authors.affiliation: Fundação Hospitalar de Minas Gerais (FHEMIG), <location>State of Minas Gerais, Brazil</location>
authors.forename: Fernando Madalena
authors.initials: FM
authors.lastname: Volpe
mesh_terms: D001938:Brazil / Q000453:epidemiology; D002947:Cities / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D012621:Seasons; D012737:Sex Factors; D013405:Suicide / Q000706:statistics & numerical data*
keywords: Brazil; cosinor analysis; latitude; seasonality; suicide