The prevalence of mental illness in young people in custody over time: a comparison of three surveys in New South Wales.

Few studies have examined the prevalence of mental illness in young people over time within the same jurisdiction. In the current study, we compared data from three large surveys of youth in custody in New South Wales, conducted in 2003, 2009 and 2015. We examined rates of mental illness, self-harm and suicidal behaviours, substance use and childhood trauma and found little consistent change over time, though some fluctuations were observed regarding certain mental illnesses and substance use. We also descriptively compared findings with observed rates for the general population and found that young people in custody showed higher levels of all examined variables. In sum, these data suggest little improvement in the well-being of young people in custody in New South Wales over time. Better identification and treatment of these issues are vital if young people are to be prevented from becoming enmeshed in the criminal justice system.