title: Psychiatric morbidity associated with same-sex sexual behaviour: influence of minority stress and familial factors.
abstract: BACKGROUND
  Increased psychiatric morbidity has been widely reported among non-heterosexual individuals (defined as reporting a homosexual/bisexual identity and/or same-sex sexual partners). However, the causes of this psychiatric ill-health are mostly unknown.
  
  
  METHODS
  We attempted to estimate the influence of minority stress and familial factors on psychiatric disorder among adults with same-sex sexual partners. Self-report data from a 2005 survey of adults (age 20-47 years, n=17,379) in the population-based Swedish Twin Registry were analysed with regression modelling and co-twin control methodology.
  
  
  RESULTS
  Rates of depression, generalized anxiety disorder (GAD), eating disorders, alcohol dependence and attention deficit hyperactivity disorder (ADHD) were increased among men and women with same-sex sexual experiences. Adjusting for perceived discrimination and hate crime victimization lowered this risk whereas controlling for familial (genetic or environmental) factors in within-twin pair comparisons further reduced or eliminated it.
  
  
  CONCLUSIONS
  Components of minority stress influence the risk of psychiatric ill-health among individuals with any same-sex sexual partner. However, substantial confounding by familial factors suggests a common genetic and/or environmental liability for same-sex sexual behaviour and psychiatric morbidity.
authors.affiliation: Centre for Violence Prevention, Karolinska Institutet, Stockholm, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Frisell
authors.forename: P
authors.initials: P
authors.lastname: Lichtenstein
authors.forename: Q
authors.initials: Q
authors.lastname: Rahman
authors.forename: N
authors.initials: N
authors.lastname: Långström
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology / Q000523:psychology; D001727:Bisexuality / Q000523:psychology* / Q000706:statistics & numerical data; D003866:Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D006716:Homosexuality / Q000523:psychology* / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D012042:Registries; D012725:Sexual Behavior / Q000523:psychology; D012931:Social Environment; D014427:Twins / Q000523:psychology*; D006113:United Kingdom / Q000453:epidemiology