title: Premorbid functioning in a national population of male twins discordant for psychoses.
abstract: OBJECTIVE
  The goal of the current study was to compare premorbid behavioral and cognitive functioning between co-twins discordant for psychotic disorder and between these pairs of twins and pairs of twins with no psychotic disorders.
  
  
  METHODS
  The authors linked data from the Israeli Draft Board Registry, which contains cognitive and behavioral assessments of all 16-17-year-old male Israeli twins, with data from the National Psychiatric Hospitalization Case Registry. Pairs of male twins who were healthy at the time of testing but discordant for psychoses later on were compared with one another and with pairs of healthy male twins.
  
  
  RESULTS
  The affected twins performed significantly worse than healthy twins on measures of individual autonomy, social functioning, and physical activity and nonsignificantly worse on measures of abstract reasoning. There were no significant differences in cognitive or behavioral scores between the co-twins who did or did not develop psychotic disorders.
  
  
  CONCLUSIONS
  The authors conclude that these findings underscore the familial nature of behavioral and cognitive deficits antecedent to psychoses.
authors.affiliation: Chaim Sheba Medical Center, Bar Ilan University, Ramat Gan, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Reichenberg
authors.forename: J
authors.initials: J
authors.lastname: Rabinowitz
authors.forename: M
authors.initials: M
authors.lastname: Weiser
authors.forename: M
authors.initials: M
authors.lastname: Mark
authors.forename: Z
authors.initials: Z
authors.lastname: Kaplan
authors.forename: M
authors.initials: M
authors.lastname: Davidson
mesh_terms: D000293:Adolescent; D004200:Diseases in Twins / Q000175:diagnosis / Q000235:genetics*; D005190:Family; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data; D006778:Hospitals, Psychiatric / Q000706:statistics & numerical data; D006801:Humans; D007361:Intelligence Tests / Q000706:statistics & numerical data; D007557:Israel / Q000453:epidemiology; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011581:Psychological Tests / Q000706:statistics & numerical data*; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D012042:Registries / Q000706:statistics & numerical data; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D012917:Social Adjustment; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics