ships. The NCS-R includes a sample of over 10,000 adolescents ages 13 and older, but the findings are not yet available.
MEB disorders in young people are a public health concern for several reasons: (1) they cause suffering to individuals and their families; (2) they limit the ability to reach normal goals for social and educational achievement; (3) they increase the risk of further psychopathology, functional impairment, and suboptimal functioning throughout life; and (4) they impose heavy costs to society because of the resultant need for extra care, the social disruption that they can cause, and the risk that affected young people will underperform as adults. The significant economic costs of treating disorders warrant an increased focus on preventing them (Smit, Cuijpers, et al., 2006). However, support for prevention programs depends on knowing the size of the problem and its societal burden and on being able to monitor reductions in that burden when prevention programs are put in place. The United States is significantly behind other countries in supporting the necessary information-gathering programs.
In this chapter, we review the evidence available from epidemiological studies to answer the following questions:
What kind of research methods and data are needed to answer questions about areas of high priority for prevention?
How prevalent are MEB disorders of major public health concern?
Is prevalence increasing or decreasing?
How many new cases are there (incidence)?
Is incidence increasing or decreasing?
At what age do diagnosable disorders first occur (onset)?
What is known about factors affecting prevalence, incidence, and age of onset?
Are rates of these factors increasing or decreasing?
Are some groups at particularly high risk for specific disorders?
Chapters 4 and 5 provide additional information related to the factors that affect the prevalence of disorders and define high-risk groups. A closely related set of questions deals with the cost to society of the harm caused by MEB disorders and the cost-effectiveness of prevention. These are addressed in Chapter 9.
The prevention of disease is a challenge for the whole community, not just for clinicians and their patients. Prevention is, by definition, an intervention that occurs before it is known who will develop a disorder and who will not. It follows that epidemiological information about whole