title: Sex-sensitive cognitive performance in untreated patients with early onset gender identity disorder.
abstract: BACKGROUND
  We explored whether the cognitive performance of gender identity disorder patients (GID) was comparable to that of their biological sex or skewed towards that of their gender identity.
  
  
  METHODS
  We tested four potentially sex-sensitive cognitive factors (rotation, visualization, perception, and verbalization) as well as two neutral factors (logic and arithmetic) in GID patients from Norway (GID-N, n = 33) or the USA (GID-US, n = 19) and in a control group (C, n = 29). The testing was undertaken prior to cross sex hormone treatment. Four-way ANOVA was applied in the final analysis of the cognitive performance and its dependency on different predictors (age, biological sex, education, group).
  
  
  RESULTS
  In both GID groups as well as in the control group (C) males excelled in visualization and rotation, also when controlling for potential confounders (biological sex, group, age and education). No female advantage was detected. Furthermore, no interaction between biological sex and group assignment was revealed in the samples.
  
  
  CONCLUSIONS
  In this study the cognitive pattern of GID patients is consistent with that of their biological sex and not that of their gender identity.
authors.affiliation: Department of Psychiatry, University of Oslo, Ullevål Hospital, 0407 Oslo, Norway. i.h.haraldsen@psykiatri.uio.no
authors.forename: I R
authors.initials: IR
authors.lastname: Haraldsen
authors.forename: S
authors.initials: S
authors.lastname: Opjordsmoen
authors.forename: T
authors.initials: T
authors.lastname: Egeland
authors.forename: A
authors.initials: A
authors.lastname: Finset
mesh_terms: D000328:Adult; D003071:Cognition; D005260:Female; D005783:Gender Identity; D006801:Humans; D008128:Logic; D008297:Male; D010465:Perception; D012399:Rotation; D012727:Sex Characteristics; D014705:Verbal Behavior; D014796:Visual Perception