Epidemiologists have used impact fractions (e.g., attributable
fractions) to study the influence of various risk factors on the rates
of physical diseases within the community. In this study, impact
fractions are applied to a psychiatric epidemiologic problem in order
to examine the impact of childhood sexual abuse (CSA) on the mental
health status of a community. Analysis of the Los Angeles
Epidemiologic Catchment Area (LAECA) data indicate that a history of
CSA significantly increases an individual's odds of developing eight
psychiatric disorders in adulthood. On the community level, however,
it is estimated that 74% of the exposed psychiatric cases (i.e., those
with a history of CSA), and 3.9% of all psychiatric cases within the
population can be attributed to childhood sexual abuse. Intervention
implications are discussed.