ABSTRACT: Psychosocial problems such as depression, anxiety, and substance abuse are common and burdensome in young people, particularly those with long-term physical conditions such as asthma and diabetes. In New Zealand, "screening" for such problems is undertaken routinely only with Year 9 students in low-decile schools and opportunistically in pediatric settings using a nonvalidated and time-consuming clinician-administered Home, Education/employment, Eating, Activity, Drugs, Sexuality, Suicide/depression, Safety (HEEADSSS) interview. The Youth version, Case-finding and Help Assessment Tool (YouthCHAT) is a relatively new, locally developed, eTablet-based composite screener for identifying similar psychosocial issues to HEEADSSS. Based on individually validated screening instruments, it is self-administered within minutes. Preliminary testing has revealed its acceptability to young people, but further research is required to expand its modules to cover all HEEADSSS domains, to evaluate its acceptability for young people with and without long-term physical conditions, and to compare its effectiveness against HEEADSSS.Our aim is to (1) ascertain acceptability and utility of YouthCHAT for children with long-term physical illness and high school students, (2) validate three additional YouthCHAT domains against comparable HEEADSSS domains, and (3) compare the performance of YouthCHAT and HEEADSSS in the high school setting.During the first phase of the study, three additional YouthCHAT domains were codesigned with high school students. During the second phase of the study, the updated version of YouthCHAT will be administered to 30 young people with long-term physical conditions, and to 150 high school students either before or after HEEADSSS in the form of a randomized trial with counter-balanced design. Primary outcomes include comparability between HEEADSSS and YouthCHAT in detecting psychosocial issues, and time to administer; acceptability of YouthCHAT as an acceptable alternative or companion to HEEADSSS assessment; and the utility of YouthCHAT in helping streamline assessment processes.Recruitment for the first phase of this project commenced in November 2016, and the phase will run from February to November 2017.If YouthCHAT is found to be acceptable to study participants and as effective as a HEEADSSS assessment, it could be an innovative and more efficient means of routine screening for common psychosocial health issues in young people with and without long-term physical conditions.Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12616001243404p; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371422 (Archived by WebCite at http://www.webcitation.org/ 6rmlEiM1L).