A retrospective study was carried out on 44 patients with major depression to study familial characteristics and to determine whether this patient population could be prospectively characterized. Two groups were differentiated: the first consisted of suicidal depressive patients, and the second consisted of non-suicidal depressive patients. A discriminant analysis was then made on two variables: health locus of control for the depressive patient, and the adaptability and cohesion factors for the existing couple, the original family and the nuclear family. This analysis provided a psychological profile of the suicidal patient and his family based on the individual's health locus of control, and indicated certain psychological and familial predisposing factors. The results showed that the family has a considerable influence on the health of a suicidal depressive subject compared to that of a non-suicidal depressive individual. The capacity for adaptability is less and the attitudes are more rigid in the former subject's family than in the latter individual's family. These results have been discussed. (C) 2000 Editions scientifiques et medicales Elsevier SAS.