1. Abstract Project 1 will examine the impact of increasing availability of coordinated specialty care (CSC) for patients in their first episode of psychosis (FEP). The growing clinical evidence base supporting CSC, combined with recent federal/state policy changes, has led to increased financing and availability of CSC care in the United States. There is, however, limited information on the impact of these changes on patients or clinical care, and limited data to guide future policy decisions. Moreover, these changes are occurring within a highly fragmented and under-resourced delivery system for mental health care. For example, in many parts of the United States, there are few or no psychiatrists in the area, much less mental health clinics that could implement CSC. Recent federal increases in FEP financing help address these needs, but the funds are limited and future investment decisions will need to be judicious. To address these gaps, we propose to use population level information from multiple sources, starting with the Massachusetts All Payer Claims Database (APCD), supplemented with state data on FEP clinics, and other area-level information. We will apply state-of-the-art statistical approaches for making causal inferences about the growth in CSC availability and our study outcomes. We have three study aims: 1) Differential access ? we will compare the characteristics and history of patients receiving care in clinics offering CSC versus elsewhere; 2) Outpatient care ? estimation of the effect of receiving care in a clinic offering CSC on outpatient process measures, e.g., time to follow-up care, assessment of lipid status, and adherence to antipsychotic drug therapy; and 3) Unfavorable clinical events ? examination of the effects on emergency department visits or hospitalizations. Our approach addresses several major gaps in the literature by including as much as ten years of follow-up after diagnosis, leveraging data on tens of thousands of newly diagnosed patients (thereby having adequate power to estimate changes precisely), and having near complete follow-up on all subjects (through the state APCD). This information will supplement existing knowledge from prior clinical trials, support the other projects in this NIMH P50 LEAP Center, and help frame the potential generalizability of information gained from advanced mental health clinics. This information could help inform federal and state policy as well as decisions by patients, clinicians, and organizational decision-makers.