Journal Issue: Juvenile Justice Volume 18 Number 2 Fall 2008
The Prevalence of Mental Disorders among Adolescent Offenders
Two kinds of studies address questions about the social consequences of the links between mental disorders and delinquency. One type examines the degree of "overlap" between a community's population of youth with mental disorders and its population of youthful offenders. Knowing this overlap gives some notion of the risk of official delinquency for youth with mental disorders and the degree to which mental disorders of youth contribute to a community's overall delinquency. The second type of study examines the proportion of youth with mental disorders within juvenile justice facilities or programs. These studies provide information with which to formulate policy about treating and managing youth with mental disorders in juvenile justice custody.
It is important to recognize that these two types of research begin with very different populations, even though they both address the relation between mental disorder and delinquency. The first typically focuses on all delinquent youth in the community, while the second examines only delinquent youth placed in juvenile pretrial detention centers when they are arrested or in juvenile correctional facilities when they are adjudicated. This distinction is further complicated, as discussed later, by the fact that not all youth in juvenile justice facilities are necessarily delinquent.
Epidemiologic Studies of Mental Disorder and Delinquency
Some studies have identified a significant overlap between the populations of youth served by community mental health agencies and youth in contact with the community's juvenile court.23 These studies are few in number, but they have found that the risk of juvenile court involvement among a community's young mental health clients is substantial. For example, a study in one city found that adolescents in contact with the community's mental health system during a nine-month period were two to three times more likely to have a referral to the juvenile justice system during that period than were youth in the city's general population.24 Youth in contact with a mental health system's services, however, are not the sum of a community's youth with mental health needs because many receive no services. The results of the study above probably represent the proportion of more seriously disturbed youth who have juvenile justice contact. Even so, merely knowing that youth "have contact" with the juvenile justice system tells us little about their offenses or even whether they offended at all.
Very few studies have used samples that make it possible to identify both the proportion of delinquent youth in a community who have mental disorders and the proportion of youth with mental disorders who have been delinquent. The few that have, however, are large studies with careful designs.
One examined a community population (drawn from several cities) that identified youth with persistent serious delinquency (repeat offending) and youth with persistent mental health problems (manifested multiple times).25 About 30 percent of youth with persistent mental health problems were persistently delinquent. But among all persistently delinquent youth, only about 15 percent had persistent mental health problems.
Another recent study examined the relation between mental disorders during adolescence and criminal behavior when those youth became adults.26 Delinquencies and adult criminal arrests were recorded for a sample of youth in a large geographic region aged nine through twenty-one. The youth were also assessed for mental disorders three times between the ages of nine and sixteen. A diagnosis at any one of these three points identified the youth as having a mental disorder "sometime during childhood or adolescence."
In this study, youth who were arrested between the ages of sixteen and twenty-one included a considerably greater share of youth who had had mental disorders in adolescence than those who were not arrested—for males, 51 percent as against 33 percent. This finding does not mean that 51 percent of the arrested group had mental disorders at the time of their arrest, but that they had had a mental disorder sometime in adolescence. It also does not mean that the majority of youth who had mental disorders in adolescence were arrested in adulthood. A different statistical procedure in this study, called "population attributable risk," addressed that question. It showed that the risk of adult arrest among individuals who had mental disorders at some time during adolescence was about 21 percent for women and 15 percent for men.
These few studies suggest the following conclusions, all of which need further confirmation. First, consistent with the clinical research reviewed earlier, youth who have mental disorders are at greater risk of engaging in offenses than youth without mental disorders. It is possible that treating their disorders would reduce that risk. But most youth with mental disorders do not engage in offenses that involve them in juvenile or criminal justice systems. Second, youth with mental disorders represent only a minority of all youth who engage in delinquent behavior, although the share is somewhat disproportionately greater than their prevalence in the general community. If those youth received treatment that reduced their delinquency, it is possible that overall rates of delinquency in the community would fall somewhat, but the majority of delinquencies are not related to mental disorders.
Third, rates of delinquency are higher among youth with certain types of emotional disorders— for example, depression or anxiety co-morbid with substance use disorders— and among youth with chronic and multiple disorders (seriously emotionally disturbed youth). Finally, a few studies have suggested that youth with mental disorders make up a somewhat greater proportion (although still a minority) of youth who were arrested for more serious and violent delinquencies or crimes.27
Mental Disorder in Juvenile Justice Settings
Research on the subset of delinquent youth who enter juvenile pretrial detention centers and correctional programs cannot tell us the relation between mental disorder and delinquency, because most youth who engage in delinquencies are not placed in secure juvenile justice programs. Such studies, however, are extremely important for public policy, because they identify the scope and nature of mental disorder among youth for whom the juvenile justice system has custodial responsibility.
Until recently the precise prevalence of mental disorders among youth in juvenile justice custody was unknown. Estimates varied widely from study to study, largely because of inadequate research methods or differences from one study site to another.28 In the past decade, however, well-designed studies executed in a variety of sites have provided a reliable and consistent picture. Those studies have found that among youth in various types of juvenile justice settings—for example, pretrial detention centers where youth are taken soon after arrest—about one-half to two-thirds meet criteria for one or more mental disorders.29 The prevalence of mental disorders is much higher in juvenile justice settings than it is among youth in the U.S. general population, which is about 15 to 25 percent.30
Across these studies, the rate is higher for girls than for boys.31 The overall prevalence rate does not vary greatly between younger and older adolescents or for youth with various ethnic and racial characteristics, although age and race differences are sometimes found for specific types of disorders and symptoms.32 As described in the earlier clinical review, about two-thirds of youth in juvenile justice custody who meet criteria for a mental disorder (that is, about one-third to one-half of youth in custody) meet criteria for more than one disorder.33
I will focus later on the implications of these statistics for the juvenile justice system's best response to mental disorders among youth in its custody. The high prevalence of mental disorder in juvenile justice facilities does not necessarily define the need for treatment. Some youth who meet criteria for mental disorders are experiencing their disorders temporarily and need only emergency services, while a smaller share—about one in ten—represents a core group of youth with chronic mental illness who can be expected to continue to need clinical services into adulthood.34 Some are functioning fairly well despite their symptoms, while others are barely able to function at all. And some have mental health needs, such as learning disabilities, that were not even included in the recent studies of prevalence among youth in juvenile justice settings.
Reasons for the High Prevalence of Mental Disorders in Juvenile Justice Programs
Why are mental disorders so prevalent among adolescent offenders in juvenile justice settings? Three perspectives—clinical, socio-legal, and inter-systemic—help to explain. They are not competing explanations. All probably play a role, and no evidence suggests that one is more important than the others.
From a clinical perspective, it is likely that the same symptoms of mental disorder that increase the risk of aggression also increase the likelihood that youth will be placed in secure juvenile justice facilities for any significant period of time. When police officers arrest youth, usually those youth are not placed in pretrial detention. Nor is detention reserved for the most serious offenders—in fact, youth arrested for very violent offenses typically do not make up the majority of youth in detention. Those youth who are detained more than a few hours are those who have been more unruly or unmanageable at the time of their arrest, which satisfies detention criteria regarding a risk that they will be endangered, or might endanger others, if not detained.
Youth with mental disorders frequently have symptoms involving impulsiveness, anger, and cognitive confusion that can make them less manageable and a greater risk to themselves or others, especially under the stress associated with their offense and arrest. Thus, among youth who are detained, a significant share is likely to have mental disorders that create unmanageable behavior—more so than for youth without mental disorders and more so than their peers with less severe mental disorders. This likelihood makes it no surprise that youth with mental disorders contribute disproportionately to detention populations.
From a socio-legal perspective, recent changes in laws applied to youths' delinquencies may have increased the likelihood that youth with mental disorders will enter the juvenile justice system. Before the 1990s, law enforcement officers, juvenile probation departments, prosecutors, and judges typically had some discretion regarding whether they would arrest or prosecute youth with mental disorders when they engaged in illegal behaviors, especially if those behaviors involved minor offenses committed by younger adolescents without offense histories. But a wave of serious juvenile violence during the late 1980s caused virtually all states to revise their juvenile justice statutes during the 1990s to rein in this discretion.35 Under the new laws, certain charges or offenses required legal responses based on the nature of the offense alone, not the characteristics or needs of the individual youth. Penalties more often involved custody in secure juvenile facilities, thus reducing the likelihood that youth could receive mental health services in the community after their adjudication. An unintended consequence of these changes in law, therefore, was an increase in the share of youth with mental disorders coming into the system rather than being diverted on the basis of the juvenile court's discretion.
A final, inter-systemic, explanation involves the dynamic relation between systems that serve youth. During the 1990s, most states saw a reduction in the availability of public mental health services for children, especially inpatient services.36 It is possible that less adequate treatment contributed to increased delinquencies among youth with mental disorders. But it is certain that many communities began using the juvenile justice system to try to fill the gap caused by decreased availability of mental health services.
This phenomenon was documented in media articles, the observations of juvenile justice personnel, and government reports beginning in the mid-1990s and continuing into the early 2000s.37 Some parents of children with serious mental disorders began urging police to arrest their children, knowing that courts could "order" mental health services that were becoming nearly impossible for parents to get on their own. Soon the local juvenile pretrial detention center was becoming the community's de facto mental health center that provided emergency mental health services or simply acted as a holding place for seriously disturbed youth who had nowhere to go.
In summary, these three factors—clinical, socio-legal, and inter-systemic—may together produce a prevalence of mental disorder in juvenile justice settings that does not represent the actual relation between adolescent mental disorder and delinquency. That high prevalence does, however, represent a demand on the juvenile justice system to respond to youth in custody who have mental disorders, and the demand is almost overwhelming. Some of those youth are in secure custody because they have committed serious crimes, others because the legal system has widened the door to juvenile justice processing, and many because their symptoms make them difficult to handle and they have no place else to go.
The problem requires a solution, and the multiple causes of the problem as well as the various types of youth involved suggest that the solution will be complex. What have clinicians and researchers learned that can help us determine the appropriate response?38



