Competing predictions have been made concerning the motivation for CSA survivors to participate in retrospective research. It has been suggested that CSA survivors may be unwilling or reluctant to participate because painful information must be disclosed, thus lowering prevalence rates; alternatively, it is theorized that CSA survivors are more motivated to “tell their story,” thus raising prevalence rates. Using data from the Adverse Childhood Experiences (ACE) study, the researchers were able to assess the relation between self-reported history of CSA and participation in retrospective research. Questionnaires requesting sensitive information on childhood experiences were sent to 13,494 adult HMO members who had completed a standardized health history from August through November 1995 and January through March 1996. Of the total, 9,508 (70.5 percent) returned the questionnaire, while 3,986 did not. Multiple logistic regression was used to determine whether self-reported CSA influenced the probability of response to the questionnaire. Analysis of respondents and nonrespondents yielded some support for the notion that CSA survivors are likely to cooperate with requests for information on these experiences. In addition, the strength of the associations between CSA and health or psychosocial problems in adulthood was remarkably similar for respondents and nonrespondents to the questionnaire. While research about the long-term effects of CSA that depends upon retrospective reports from CSA survivors may suggest an upward bias, the researchers found no evidence of this type of bias in the data from the ACE study. Rather, the data suggest that if any bias due to nonresponse exists, it would likely result in estimates of the effects of CSA that are slightly downwardly biased. References, tables and figure