There are many factors that influence the manifestation and course of child psychiatric disorders. Such influences are: genetic factors and temperament, natural course of the disorder, developmental factors, age and sex, socio-familiar influences, systematic influences and accidental influences, risk factors and protective factors. With regard to the course of child psychiatric disorders, three types can be distinguished: disorders which continue into adulthood (continuity type), disorder with strong dependence on developmental factors, diminishing from childhood to adulthood, and newly manifested disorders starting during adolescence and following the same rules as psychiatric disorders in adulthood. In this regard the continuity hypothesis applies only to some child psychiatric disorders and not to others. Besides the three types concerning the course of child psychiatric disorders, it should be mentioned that some disorders change their symptomatology on the way to adulthood. For example, hyperkinetic children frequently develop antisocial behaviour, delinquency and alcoholism during adult age.