Judicial Initiative Mental Health and Substance Abuse Treatment Improvement Act of 2007

Judicial Initiative Mental Health and Substance Abuse Treatment Improvement Act of 2007 - Amends the Juvenile Justice and Delinquency Prevention Act of 1974 to direct the Administrator of the Office of Juvenile Justice and Delinquency Prevention to make grants to train state juvenile justice system officers and employees regarding appropriate access to mental health and substance abuse treatment services for juveniles.

Directs the Attorney General to make grants to partnerships between state and local juvenile justice and mental health agencies for programs to divert juveniles from incarceration and for mental health and substance abuse screening and treatment.

Establishes a Federal Coordinating Council on Criminalization of Juveniles to study and coordinate federal criminal and juvenile justice and mental health and substance abuse activities.

Amends the Violent Crime Control and Law Enforcement Act of 1994 to require states seeking eligibility for violent offender incarceration grants to implement (or begin to implement), not later than January 1, 2008, a program of mental health screening and treatment for juvenile and other offenders during periods of incarceration and supervision.