"Individuals with co-occurring disorders experience substance use and another mental health disorder simultaneously. The conditions may precipitate or exacerbate one another, or they may exist independently … In youth with co-occurring disorders, the complexity of this interaction is heightened. Unique combinations of symptom patterns and behaviors can prevent youth from functioning adequately. Furthermore, co-occurring disorders in youth can impact brain development, making sustained recovery even more difficult … Overcoming these challenges can be particularly difficult for youth involved in the juvenile justice system, who often have little access to appropriate services and support." This website provides an excellent resource regarding issues related to justice-involved juveniles with co-occurring disorders. Sections of this website cover: prevalence of disorders among youth in the juvenile justice system; poor outcomes linked to co-occurring disorders; identification—screening (Massachusetts Youth Screening Instrument Version 2 (MAYSI-2), and Global Appraisal of Individual Needs Short Screener (GAIN-SS)), and assessment (Practical Adolescent Dual Diagnostic Interview-5 (PADDI-5), Diagnostic Interview Schedule for Children (DISC), and World Mental Composite International Diagnostic Interview (WMH-CIDI)); treatment—history, effective treatment, integrated co-occurring treatment (ICT) model, multisystemic therapy (MST) for juvenile offenders, and family integrated transitions (FIT); addressing youth with co-occurring disorders in court—advancing juvenile treatment courts—developing effective policies, new directions, and providing effective treatment; key websites; and critical resources.