PROJECT SUMMARY / ABSTRACT Psychotic disorders are characterized by high rates of suicidal ideation and behavior, and the risk for suicide appears to be greatest during the earliest stages of psychosis. A recent meta-analysis showed that the majority of youth at clinical high-risk (CHR) for psychosis experience suicidal ideation, and that approximately one in five make at least one suicide attempt. There are, however, no suicide prevention interventions specifically tailored to the needs of transition-aged youth at CHR, and no current best practice guidelines for how to respond to suicide risk in this population. The Youth-Nominated Support Team (YST) intervention has recently been shown to reduce mortality among adolescents and is potentially highly adaptable within the context of existing CHR services. YST is intended as an adjunctive treatment and is primarily delivered towards support persons rather than the youth themselves, and therefore would not interfere or overlap with the already extensive direct services provided in CHR treatment settings. The proposed project intends to adapt the YST intervention for CHR populations and to provide pilot efficacy data for a larger subsequent randomized trial. Specifically, we aim to: (1) adapt YST for CHR based on stakeholder input (i.e., clients, family/friends, clinicians) and to develop a new treatment manual; (2) to implement YST in a single CHR clinic and to revise the intervention based on input from clients, providers, and support persons, and (3) to conduct a pilot randomized clinical trial at four SAMHSA funded CHR sites. For the first stage of this study, we intend to conduct six focus groups (two of clients, two of family members, and two of clinicians) to gather input on needs and preferences regarding suicide prevention. This information will be incorporated into the YST protocol through expert consensus meetings (i.e., study investigators, clinicians, and consultants) and used to develop a treatment manual. During the second stage of the project, we will conduct a small feasibility study using this intervention manual at the primary study site (N=8), and will again gather input from clients, providers, and support persons to further revise the treatment manual. In the final stage, we will conduct a pilot randomized clinical trial of the adapted YST intervention at four CHR clinics (N=70), comparing the adapted YST intervention to an active control condition consisting of safety planning, crisis resources, and means restriction. The proximal targets will be social connectedness, hope, and treatment engagement, and the distal targets suicidal ideation and behavior (e.g., attempts, preparatory actions). This study will provide the first clinical trial data for targeted suicide prevention among the CHR population. Findings will inform best practices for addressing suicide risk in the CHR phase of illness and facilitate the development of a subsequent larger randomized clinical trial incorpor...