title: Seasonal patterns of birth for subjects with bulimia nervosa, binge eating, and purging: results from the National Women's Study.
abstract: OBJECTIVE
  Studies of birth patterns in anorexia nervosa have shown relative increases between March and August, while studies in Bulimia Nervosa (BN) have been negative. Since there are no studies using representative, nonclinical samples, we looked for seasonal birth patterns in women with BN and in those who ever endorsed bingeing or purging.
  
  
  METHODS
  A national, representative sample of 3,006 adult women completed structured telephone interviews including screenings for bulimia nervosa (BN) and questions about month, date, and year of birth. Season of birth was calculated using traditional definitions. Differences across season of birth between subjects with (n = 85) and without BN (n = 2,898), those with (n = 749) and without bingeing (n = 2,229), and those with (n = 267) and without any purging (n = 2,715) were compared using chi-square analyses.
  
  
  RESULTS
  There were significant differences across season of birth between subjects: (1) with and without BN (p = 0.033); (2) with and without bingeing (p = 0.034), and; (3) with and without purging (p = 0.001). Fall had the highest relative number of births for all categories, while spring had the lowest.
  
  
  CONCLUSIONS
  In a national representative study of nontreatment seeking subjects significant differences in season of birth were found for subjects with lifetime histories of BN, binge eating and purging. © 2011 by Wiley Periodicals, Inc. (Int J Eat Disord 2012).
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, USA. tbrewerton1@comcast.net
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Brewerton
authors.forename: Bonnie S
authors.initials: BS
authors.lastname: Dansky
authors.forename: Patrick M
authors.initials: PM
authors.lastname: O'Neil
authors.forename: Dean G
authors.initials: DG
authors.lastname: Kilpatrick
mesh_terms: D000328:Adult; D002032:Bulimia / Q000175:diagnosis*; D052018:Bulimia Nervosa / Q000175:diagnosis*; D005260:Female; D006306:Health Surveys; D006801:Humans; D036801:Parturition; D012621:Seasons; D014839:Vomiting / Q000175:diagnosis*; D014930:Women