1. Objectifs

Intentions :
In this study, the authors « [...] tes[t] the independence of liability to depression and suicide using a three-group family-study design. Specifically, rates of recurrence of suicidal behavior in relatives of suicide probands who died during an episode of major depressive disorder were compared with recurrence rates of suicidal behavior in relatives of 1) living depressed probands with major depressive disorder but no history of suicidal behavior and 2) living comparison probands without major depressive disorder or suicidal behavior.» (p. 1125)

Questions/Hypothèses :
The authors’ hypothesis is « [...] that cluster B disorders and impulsive-aggressive behavior are intermediate phenotypes of suicide. » (p. 1125)

2. Méthode

Échantillon/Matériau :
« Participants were 718 first-degree relatives from 120 families: 296 relatives of 51 depressed probands who committed suicide, 185 relatives of 34 nonsuicidal depressed probands, and 237 relatives of 35 community comparison subjects. » (p. 1124)

Instruments :
« For proband comparability, we used proxy-based interviews to characterize living probands. DSM-IV (37) psychiatric diagnoses were obtained using the SCID-I (38) and SCID-II (39) interviews. » (p. 1126)

Type de traitement des données :
Analyse statistique

3. Résumé

« The present study investigated, by design, the extent of overlap between familial liability to major depressive disorder and suicide. We found that the liability to suicide is overlapping with, yet distinct from, liability to major depressive disorder. A marked gradient emerged consistent with this distinct and overlapping liability. Moreover, our analyses indicate that cluster B traits are endophenotypes of suicide and account for, in part, familial aggregation of suicidal behavior. » (p. 1132)