[The role of family studies in research of neurobiological basis of depressive disorders].

Depression belongs to a large class of multifactorial diseases and genetic factors play a significant role in its formation, development and clinical manifestations. The authors present an overview of current studies of recurrent depressive disorder (RDD), a heterogeneous group of disorders with phenotypically similar psychopathological symptoms. A study of families with a high risk for RDD using clinical and biological (including genetic) approaches can greatly help in understanding of the neurobiological basis of depressive disorders, as well as in the identification of endophenotypes of depression. The most important criterion of the endophenotype is its heritability, which can be proved only within the framework of family design research. Comprehensive clinical and molecular genetic studies based on family design have the best prospects.