aggravated assault in 1996—a rate that is almost two times higher than the adult rate (Snyder and Sickmund, 1999). Victimization rates are highest for American Indians and roughly equivalent for Whites and African Americans. Most of these crimes are perpetrated by friends and acquaintances rather than by relatives (11 percent of the total). Bearing witness to community violence is very common in inner city neighborhoods, with estimates of one-third or more of children and adolescents being exposed (for review, see Margolin and Gordis, 2000).
Altogether, these disparate statistics on the prevalence of various forms of trauma indicate that, by adulthood, past traumatic exposure is widespread. In one large study, about 52 percent of adults report having ever been exposed to at least one type of childhood trauma covered in this chapter (Felitti et al., 1998).
The study of childhood trauma is beset by methodological limitations (NRC, 1993). These limitations have implications for efforts to understand the relationship between early childhood trauma and later suicidal behavior. The first area of limitation concerns estimates of the incidence and prevalence of childhood trauma. There are two general sources of information about the magnitude of the problem and the relationship of child trauma to other health outcomes: official records; and self-report by victims/survivors and/or their caregivers and parents. Official report statistics are compiled annually from mandated reporters, most commonly social service, education, law enforcement, and medical personnel as well as non-mandated categories of persons including neighbors, kin, and friends. Official statistics cover several types of reportable trauma: neglect, physical and sexual abuse, psychological maltreatment, medical neglect, and miscellaneous types of abuse. Official records are thought to underreport and underestimate the magnitude of child maltreatment because generally only the more severe and “substantiated”6 cases are reported to local and state authorities, which in turn report their findings to the federal government. Some states include cases that are “indicated,” or those cases about which there is a high level of suspicion but insufficient evidence for adjudication by child protection professionals.
The other source of information about the magnitude of child maltreatment—self-reports by victims/survivors—is essential because of underestimation by official records. In a large national sample of more than