[Severe depression : environmental factors of severe depression : depression in parents].

Depression in parents is a significant risk factor for depression in the offspring at all ages, and also modulates depression severity. Depression severity increases with the number of parents affected, but the presence of grandparents without depression may be protective. Most studies have focused on the transmission of maternal depression, however, the few studies examining paternal depression observe that it impacts more on behavioral than emotional disorders. The genetic component of inter-generational transmission increases with the severity of depression. The interaction between parental depression, environment and onset of depression in children is complex due to the secondary effects of depression which range from in utero disturbances of cortisol secretion via the placenta, to poor parenting skills and high rates of family conflict and co-morbidity. While pharmaceutical treatment of depression in parents reduces the risk in children, it is also necessary to modify secondary factors as these may persist in the face of treatment and continue to increase risk. A number of questions remain to be explored ; the effect of the age of the child when the parent becomes depressed, the differential impact according to the child's sex, and the effect of duration of exposure.