reflect an awareness that persistent behavioral changes are very hard to maintain.
Although all modes of injury need further investigation, one that is especially demanding—and perplexing—is violence, now recognized as a major national public health problem. Violence is linked with mental health in several ways. First, of course, violence begets mental health problems: victims of violence often experience severe emotional and psychological disturbances. Second, achieving a better understanding of mental disorders can help inform efforts to prevent such violent acts as homicide and suicide. Intertwined in this issue as well is the frequent association of alcohol and drugs with violent or abusive behavior.
Researchers have addressed the problem of violence in a number of studies. For example, there is evidence from studies conducted across societies and within societies that exposure, especially among some impressionable children and youths, to scenes of aggression and violence on television and in other media fosters our acceptance and expectation of violence in America and probably contributes to the frequency of aggressive acts themselves (Rosenberg, O'Carroll, and Powell, 1992). Studies also indicate that children who witness violence directly —an increasingly frequent situation in many urban areas—often develop symptoms associated with post-traumatic stress disorder, including diminished ability to concentrate in school, persistent sleep disturbances, disordered attachment behaviors with parents or significant caregivers, and changes in orientation toward the future that lead to increased risk-taking behaviors (Groves, Zuckerman, Marans, and Cohen, 1993). Children who witness domestic violence may be particularly vulnerable to emotional and developmental problems. Many aspects of the causes of violence and how violence can be prevented remain to be empirically tested, however, and the problem is presented here primarily to illustrate a broad-scale beginning in tackling one of the most destructive and powerful problems in society today, and one with important implications for prevention of mental disorders.
The Centers for Disease Control and Prevention (CDC) is now conducting a multifaceted community-based research effort devoted to youth violence prevention (Rosenberg et al., 1992). Multifaceted programs are needed because of the complex web of factors that cause violence and violence-related injuries, and community-based programs are needed to ensure community residents' involvement in, ownership of, and responsibility for the activities. Six key strategies have been identified, representing an orderly progression of research and implementation. The strategies are (1) developing prevention materials; (2) establishing community demonstration programs; (3) rigorously evalu-