One of the essential ingredients for mental health is that the infant and young child should experience a warm, intimate, and continuing relationship with his mother or permanent mother substitute, such that both find satisfaction and enjoyment in the relationship. Maternal deprivation can thus be considered as an insufficiency of interaction between the child and a mother-figure, to the degree that identification with the maternal figure is not made and with the result that personality development is impaired.
Deprivation occurs when an infant or young child lives in an institution or hospital where he has no major substitute mother and where he receives insufficient maternal care, or when a young child lives with his mother or permanent substitute mother, from whom he receives insufficient care and with whom he has insufficient interaction. Deprivation may also come about through the child's own inability to interact with a mother-figure despite the fact that one is present and ready to give sufficient care – this inability to interact being consequent on and presumably caused by previous deprivation experiences.
Maternal deprivation can result in the growth pattern of a failure to thrive, a decline from a previously established growth pattern, despite an adequate caloric intake.