Introduction

The epidemiological study of anxiety disorders in children involves individuals with anxiety disorders who receive treatment as well as individuals who do not receive treatment. (For brevity ‘child’ is used to include adolescent.) In this way it is possible to study relatively unselected samples. This is an advantage of epidemiological over clinical samples. Because there may be factors other than the psychopathological manifestation in itself that bring children into contact with mental health services, clinical samples may be highly selected. For example, we assessed the association between a large number of factors and mental health services use in a community sample (Verhulst & van der Ende, 1997). It was found that adverse family factors such as living in a one-parent family, changes in the family composition and problems in family functioning were strongly associated with mental health services use in addition to the level of psychopathology in the child. It was concluded that among referred children, those living under problematic family circumstances were overrepresented, irrespective of the level of psychopathology.

Because epidemiological studies focus on the whole spectrum of problem behaviours, they provide information on quantitative and qualitative aspects of anxiety manifestations that are associated with maladaptive functioning. It may well be that certain anxiety phenomena that many children in the general population show to some degree are associated with rather undisturbed daily functioning, whereas other anxiety manifestations can be quite handicapping.

One of the first true epidemiological studies was the study by Lapouse & Monk (1958) who assessed the prevalence of parent-reported problems in a representative sample of 6–12-year-old children in Buffalo, New York.