A field of developmental psychology that studies the features of the psychosocial development of children and adolescents due to organic, functional or social factors that slow down or modify normal developmental processes. These features can complicate social adaptation, successful education and further professional self-determination. The object of special psychology is a person with developmental disorders who are in a state of mental or social deprivation. The subject of science is the forms, mechanisms and features of the psyche that arise and manifest themselves in unfavorable conditions.