Project Summary Parental acceptance after youth come out as gay or bisexual is a protective factor for the health of this youth group; however, parents lack support in initiating and sustaining sexuality discussions inclusive of their teens’ attractions, behaviors and identities. Thus, in the absence of skills and supports, adolescents’ and parents’ mental health, health behaviors and overall family functioning tend to be negatively impacted after sons come out as gay or bisexual. The overall objective of this application is to test the efficacy of Parents ASSIST (Advancing Supportive and Sexuality Inclusive Sex Talks), a sexuality communication intervention for parents, after youth disclose gay or bisexual identities. We will conduct a randomized controlled trial with parent and gay or bisexual youth dyads (N=476) to establish the efficacy of Parents ASSIST as a hybrid 5-session online intervention that educates parents about germane sexuality-specific topics and provide communication skills for family discussions. Our Specific Aims are to (1) determine whether Parents ASSIST enhances parent-adolescent sexuality communication quality (e.g. parent- and child-reported comfort) and quantity (e.g. frequency and range of topics discussed) compared to the control group, (2) establish whether Parents ASSIST results in decreases in mental health symptomology (e.g. depressive and anxiety symptoms) among parents and gay or bisexual youth, increases dyadic health behavior (e.g. accessing preventive health services, health screening behaviors), and improves family functioning (e.g. affective response, communication, general functioning) over 12 months of follow-up, and (3) examine how theory-based variables (e.g. attitudes and norms, self-efficacy and intentions to discuss sexuality with gay or bisexual child) mediate the intervention effects on adolescent and parent mental health, parent-adolescent health behavior and family functioning over time. This proposal is innovative because it is one of few studies that investigate the role of parent-adolescent sexuality communication with gay or bisexual youth and examines both individual and dyadic health outcomes. Ultimately, fortifying the capacity of parents to initiate and broach sexuality-sensitive communication with gay or bisexual sons offers new opportunities for families to be protective of all youth.