title: Familial Liability for Eating Disorders and Suicide Attempts: Evidence From a Population Registry in Sweden.
abstract: OBJECTIVE
  Suicide attempts are common in individuals with eating disorders. More precise understanding of the mechanisms underlying their concomitant occurrence is needed.
  
  
  OBJECTIVE
  To examine the association between eating disorders and suicide attempts and whether familial risk factors contribute to the association.
  
  
  METHODS
  A Swedish birth cohort including individuals born in Sweden between January 1, 1979, and December 31, 2001, was followed up from age 6 years to December 31, 2009 (N = 2,268,786). Information was acquired from Swedish national registers. All individuals were linked to their biological full siblings, maternal half siblings, paternal half siblings, full cousins, and half cousins. Data analysis was conducted from October 5, 2014, to April 28, 2015.
  
  
  METHODS
  Eating disorders were captured by 3 variables (any eating disorder, anorexia nervosa, and bulimia nervosa) identified by any lifetime diagnoses recorded in the registers. Suicide attempts were defined as any suicide attempts, including death by suicide, recorded in the registers. We examined the association between eating disorders and death by suicide separately, but the study was underpowered to explore familial liability for this association.
  
  
  RESULTS
  Of 2,268,786 individuals, 15,457 females (1.40% of all females) and 991 males (0.09% of all males) had any eating disorder, 7680 females (0.70%) and 453 males (0.04%) had anorexia nervosa, and 3349 females (0.30%), and 61 males (0.01%) had bulimia nervosa. Individuals with any eating disorder had an increased risk (reported as odds ratio [95% CI]) of suicide attempts (5.28 [5.04-5.54]) and death by suicide (5.39 [4.00-7.25]). The risks were attenuated but remained significant after adjusting for comorbid major depressive disorder, anxiety disorder, and substance use disorder (suicide attempts: 1.82 [1.72-1.93]; death by suicide: 2.04 [1.49-2.80]). Similar results were found for anorexia nervosa (suicide attempts: crude, 4.42 [4.12-4.74] vs adjusted, 1.70 [1.56-1.85]; death by suicide: crude, 6.46 [4.38-9.54] vs adjusted, 2.67 [1.78-4.01]) and bulimia nervosa (suicide attempts: crude, 6.26 [5.73-6.85] vs adjusted, 1.88 [1.68-2.10]; death by suicide: crude, 4.45 [2.44-8.11] vs adjusted, 1.48 [0.81-2.72]). Individuals (index) who had a full sibling with any eating disorder had an increased risk of suicide attempts (1.41 [1.29-1.53]). The risk was attenuated for any eating disorder in more-distant relatives (maternal half siblings, 1.10 [0.90-1.34]; paternal half siblings, 1.21 [0.98-1.49]; full cousins, 1.11 [1.06-1.18]; half cousins, 0.90 [0.78-1.03]). This familial pattern remained stable after adjusting for the index individuals' eating disorders. Similar patterns were found for anorexia nervosa and bulimia nervosa.
  
  
  CONCLUSIONS
  These results suggest an increased risk of suicide attempts in individuals with lifetime eating disorders and their relatives. The pattern of familial coaggregation suggests familial liability for the association between eating disorders and suicide. Psychiatric comorbidities partially explain this association, suggesting particularly high-risk presentations.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Shuyang
authors.initials: S
authors.lastname: Yao
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Ralf
authors.initials: R
authors.lastname: Kuja-Halkola
authors.affiliation: Department of Psychiatry, University of North Carolina at Chapel Hill.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Thornton
authors.affiliation: Department of Psychiatry, University of North Carolina at Chapel Hill.
authors.forename: Cristin D
authors.initials: CD
authors.lastname: Runfola
authors.affiliation: Department of Psychological and Brain Science, Indiana University, Bloomington.
authors.forename: Brian M
authors.initials: BM
authors.lastname: D'Onofrio
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden4Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Catarina
authors.initials: C
authors.lastname: Almqvist
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Paul
authors.initials: P
authors.lastname: Lichtenstein
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Arvid
authors.initials: A
authors.lastname: Sjölander
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Larsson
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden2Department of Psychiatry, University of North Carolina at Chapel Hill5Department of Nutrition, University of North Carolina at Chapel Hill.
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Bulik
mesh_terms: D000328:Adult; D000856:Anorexia Nervosa / Q000453:epidemiology*; D001008:Anxiety Disorders / Q000453:epidemiology; D052018:Bulimia Nervosa / Q000453:epidemiology*; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000453:epidemiology; D005190:Family; D001068:Feeding and Eating Disorders / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000453:epidemiology; D013406:Suicide, Attempted / Q000523:psychology / Q000706:statistics & numerical data*; D013548:Sweden / Q000453:epidemiology