The results of experimental study of interaction and attachment between mother and infant in risk groups are reviewed. Complicated relation to mother is usually formed in prematurely born, having "difficult temperament", genetically threatened by development retardation children. Mothers suffering depression and those with unsteady parental behavior were examined. The breach of interaction with the nearest person is considered to be social and sensoric deprivation for an infant and disturbance of individual development as well as a threat for psychic health.