1. Objectifs

Intentions :
« In this paper, we focus on 3 critical issues raised by current family studies:
1. We attempt to confirm that schizophrenia and psychotic symptoms aggregate in families of BD [Bipolar disorder] probands recruited from community sources rather than treatment facilities, especially in a sample of known genetic homogeneity.
2. We explore the hypothesis raised in family studies that the first-degree relatives of female BD probands have elevated rates of schizophrenia and psychotic symptoms.
3. We also examine whether there is evidence for a clinical subtype of BD associated with familial aggregation for psychotic symptoms. » (p. 190)

2. Méthode

Échantillon/Matériau :
- « The final sample included 49 BD and 99 NMD [No mental disorder] probands. » (p. 190)
- « All probands reported on their own family. As well, we recruited and interviewed 168 first-degree relatives who knew the family well and agreed to participate. » (p. 190)

Instruments :
Family Interview for Genetic Studies (FIGS)

Type de traitement des données :
Analyse statistique

3. Résumé

« Although they were once considered separate nosologic entities, there is current interest in the etiologic overlap between bipolar disorder (BD) and schizophrenia. A critical issue concerns the familial basis of the overlap, specifically, the possibility of a distinct familial subtype of BD with psychotic features. [...] We recruited individuals with BD from the community and compared them with a matched group diagnosed with no mental disorder to confirm familial aggregation for BD, schizophrenia, and psychotic symptoms. We then compared BD probands both with and without first-degree relatives with psychotic symptoms on several clinical indicators to determine the specificity of the familial aggregation. [...] As expected, there was evidence for familial aggregation of schizophrenia and psychotic symptoms in families having probands with BD. Familial loading for schizophrenia and psychotic symptoms was especially notable in male relatives of female probands with BD. We found no difference in the clinical profile of probands with BD stratified for familial loading for psychotic symptoms. [...] Findings from this sample support etiologic theories arguing for a shared but nonspecific genetic etiology for BD and schizophrenia, with psychotic symptoms being a potential key indicator for genetic studies. » (p. 189)