Drs. Maryann Davis of the Transitions to Adulthood Center for Research at the University of Massachusetts Medical School and Ashli Sheidow and Michael McCart of the Oregon Social Learning have previously demonstrated that Multisystemic Therapy for Emerging Adults (MST-EA) is an intervention that successfully engages and retains young adults with serious mental health conditions in treatment. This Research in the Works is about a new trial awarded by NIMH called Effectiveness Trial of Treatment to Reduce Serious Antisocial Behavior in Emerging Adults with Mental Illness. This study builds on Drs. Davis and Sheidow’s previous work and is a randomized controlled trial comparing outcomes of 240 participants assigned to either the MST-EA intervention or enhanced treatment as usual. This study will determine if MST-EA is a more effective treatment than the enhanced usual treatment for this population. Currently, there is no intervention with proven efficacy to reduce criminal behavior for emerging adults with serious mental health conditions and this study is an important step in developing one.