One of the difficulties described in epidemiological studies about psychopathology in children 0-3 years of age appears during the assessment phase. In fact, the assessment of indicators of particular difficulties in children is hampered by the rapid processes of transformation of behavior that cross all areas of child development. The aim of this article was to provide an overview as complete as possible of all instruments used in the assessment phase of children 0-3 years. The literature shows a number of tools for evaluation and diagnosis of psychopathology that have been divided into four categories: mental development tests, interviews with parents, questionnaires and rating scales, evaluation of the parent-child assessment of specific diagnostic entities. The main features of each instrument are described.
