PROJECT SUMMARY Parental support represents the strongest predictor of sexual and gender minority youth's (SGMY) mental health. However, over half of parents react to their SGMY's disclosure with rejection. Even relatively accepting parents can experience discomfort, while SGMY often report lingering unmet needs from their parents into adulthood. Few interventions exist to help parents support their SGMY child and none has been tested in a randomized trial with efficacy for decreasing parental rejection and increasing support of their SGMY. This proposal will develop and test the efficacy of two theory-based interventions that aim to address this gap. These interventions respectively address two mechanisms shown to underlie parental rejection of SGMY – parents' unresolved negative emotions toward their SGMY and lack of empathy toward their SGMY. The first intervention – expressive writing (EW) – reduces negative emotions by helping people make sense of stressful events. In our adapted EW, we will ask non-accepting parents to write about the stressful impact that their child's SGM identity has on them across three 20-min sessions. The second intervention – attachment-based writing (ABW) – will be based on the only known intervention (called attachment-based family therapy) that builds empathy among parents of SGMY. However, the parent-focused tasks of attachment-based family therapy currently require 2-3 sessions with a trained therapist, preventing broad access. We will thus create a writing-based version of this therapy in a parallel format to EW (i.e., 3 20-min writing sessions). This adaptation will ask parents to engage with the core components of attachment-based family therapy in writing (i.e., writing about one's impact on their child, one's own attachment needs, and their child's needs). Across three aims, we will develop and test the preliminary efficacy of these two brief interventions for non-accepting parents in the Southeast US – a region with the highest anti-SGM stigma and highest SGMY mental health needs in the US. Aim 1 will engage community stakeholders, non-accepting parents, and SGMY in the Southeast to inform the writing prompts and look-and-feel of the online platform. Aim 2 will test the preliminary efficacy of EW and ABW. We will randomize 129 non-accepting parents to EW, ABW, or control. Parents will report primary outcomes (i.e., rejecting and supporting behaviors), target mediators (i.e., negative emotions, empathy), and secondary outcomes (e.g., parent and youth depression/anxiety) at baseline, post-intervention, and 3-month follow-up. We will also explore the feasibility of asking parents to enroll their child so that we can study the interventions' impact on SGMY themselves. Aim 3 will determine intervention acceptability and implementation facilitators in parent support organizations in the Southeast US. Results to mental will identify mechanisms contributing parental rejection and develop scalable approaches to re...