title: Liability indicators aggregate many years before transition to illness in offspring descending from kindreds affected by schizophrenia or bipolar disorder.
abstract: Offspring born to patients with affective and non-affective psychoses display indicators of brain dysfunctions that affected parents carry. Such indicators may help understand the risk trajectory.
  
  
  
  We followed up the clinical/developmental trajectories of 84 young offspring born to affected parents descending from the Quebec kindreds affected by schizophrenia or bipolar disorder. We longitudinally characterized childhood trajectories using 5 established risk indicators: cognitive impairments, psychotic-like experiences, non-psychotic DSM diagnosis and episodes of poor functioning, trauma and drug use.
  
  
  
  Overall, offspring individually presented a high rate of risk indicators with 39% having 3 or more indicators. Thirty-three offspring progressed to an axis 1 DSM-IV disorder, 15 of whom transitioned to a major affective or non-affective disorder. The relative risks for each risk indicator were low in these vulnerable offspring (RR = 1.92 to 2.99). Remarkably, transitioners accumulated more risk indicators in childhood-adolescence than non-transitioners (Wilcoxon rank test; Z = 2.64, p = 0.008). Heterogeneity in the risk trajectories was observed. Outcome was not specific to parent's diagnosis.
  
  
  
  Young offspring descending from kindreds affected by major psychoses would accumulate risk indicators many years before transition. A clustering of risk factors has also been observed in children at risk of metabolic-cardiovascular disorders and influences practice guidelines in this field. Our findings may be significant for the primary care surveillance of millions of children born to affected parents in the G7 nations. Future longitudinal risk research of children at genetic risk should explore concurrently several intrinsic and environmental risk modalities to increase predictivity.
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada; Université du Québec à Trois-Rivières, Département des Sciences infirmières, QC, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Paccalet
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada; Université Laval, École de Psychologie, QC, Canada.
authors.forename: Elsa
authors.initials: E
authors.lastname: Gilbert
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada; Université du Québec à Trois-Rivières, Département des Sciences infirmières, QC, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Berthelot
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada; Université Laval, Faculté de Médecine, QC, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Marquet
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada.
authors.forename: Valérie
authors.initials: V
authors.lastname: Jomphe
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada.
authors.forename: Daphné
authors.initials: D
authors.lastname: Lussier
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada; Université Laval, Faculté de Médecine, QC, Canada.
authors.forename: Roch-Hugo
authors.initials: RH
authors.lastname: Bouchard
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada; Université Laval, Faculté de Médecine, QC, Canada.
authors.forename: Denis
authors.initials: D
authors.lastname: Cliche
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada; Université Laval, Faculté de Médecine, QC, Canada.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Gingras
authors.affiliation: Centre de recherche, Centre intégré universitaire de santé et des services sociaux de la Capitale-Nationale, QC, Canada; Université Laval, Faculté de Médecine, QC, Canada. Electronic address: michel.maziade@fmed.ulaval.ca.
authors.forename: Michel
authors.initials: M
authors.lastname: Maziade
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000235:genetics*; D002648:Child; D016241:Child of Impaired Parents; D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D011618:Psychotic Disorders; D011792:Quebec; D012307:Risk Factors; D012559:Schizophrenia / Q000235:genetics*; D055815:Young Adult
keywords: Bipolar disorder; Children at risk; Developmental trajectories; Protective mechanisms; Risk endophenotypes; Schizophrenia