Prevalence of Mental Disorders in the Juvenile Justice System

Despite increasing interest in the mental health needs of children involved in the juvenile justice system, relatively little is known about the base rates of specific mental disorders in this population due to the absence of any national prevalence data. In 1992, two reviews of the existing empirical literature (Otto, Greenstein, Johnson, Friedman, 1992; Wierson, Forehand, & Frame, 1992) both concluded that relatively few well-controlled epidemiological studies had been conducted that could inform our knowledge of the prevalence of mental disorders in the juvenile justice system. Factors commonly cited that limited the generalizability of much of the existing research included: (a) failure to use random or comprehensive sampling procedures, (b) use of differing assessment instruments across studies or reliance on file information rather than structured diagnostic interviews, (c) assignment of only one diagnosis and failure to assess for multiple diagnoses/comorbidity, (d) samples being drawn from only one site or state, and (e) failure to consider how diagnostic rates might be affected by relevant demographic and historical variables such as age, gender, and length of detainment. Since the publication of these two reviews, few studies have been conducted that have significantly improved our knowledge of the prevalence of mental disorders in juvenile justice populations and national prevalence estimates of mental disorder still have not been established. Despite the limitations of existing research on the prevalence of mental disorders in the juvenile justice system, some tentative estimates can be provided for specific diagnostic categories, as well as for other clinically significant issues such as a history of child abuse, suicidal behavior, and prior mental health treatment. The following base rates are distilled from the Otto et al. (1992) and Wierson et al. (1992) reviews, as well as from more recent research, and include only those studies that used comprehensive or random sampling procedures. Given the methodological limitations already mentioned, particularly regarding the common failure to assess for co-occurring disorders, these rates should be considered as conservative estimates of the prevalence of these disorders. As well, none of the rates recited here are from studies that employed DSM-IV (American Psychiatric Association; APA, 1994) diagnostic criteria. Most of the rates reported are based on earlier versions of the DSM and used what are now outdated criteria for most diagnostic categories