Sexual minority Veterans (e.g., gay, lesbian, bisexual) are one of the highest risk populations for psychiatric disorders due in part to the experience of discrimination and stigma-based stressors (sexual minority stressors). These stressors and the associated stress responses contribute to greater severity of depression and anxiety, which confer risk for negative health outcomes (hazardous substance use and suicide). However, very few interventions target distress related to sexual minority stressors, and even fewer have been tested in Veteran Health Administration (VHA). Brief, easy to implement interventions that target distress related to sexual minority stressors are needed to address the unique mental health concerns of this high risk community of Veterans. Expressive writing is a brief, well-developed paradigm that involves writing about thoughts and emotions related to a stressful experience for at least 15 minutes, 3-5 times based on a structured writing prompt. Over 30 years of research supports expressive writing's effectiveness in reducing stress, depression, and anxiety related to a stressor. Expressive writing on a minority stressor (EWMS) has been shown to reduce depression and anxiety among sexual minority non-Veterans but has never been tested among sexual minority Veterans. The aim of the proposed study is to examine the feasibility, acceptability, and preliminary effectiveness of EWMS, a promising intervention for sexual minority Veterans. Based on consultation with experts in expressive writing and sexual minority Veteran health, EWMS will be adapted for sexual minority Veterans and a VHA clinic setting. EWMS will be implemented as a 3 session, one-on-one intervention with a therapist. The proposed EWMS protocol will be iteratively refined in a case series (n = 10), and then tested in a pilot randomized control trial (RCT; n = 54) comparing EWMS to a neutral writing control condition. Aims of the pilot RCT are: 1) demonstrate feasibility and acceptability of study procedures and EWMS using quantitative and qualitative data; and 2) examine the preliminary effectiveness of EWMS relative to control in reducing depressive and anxiety symptom severity. The proposed research aims are in direct alignment with the applicant's short term and long term training goals. The proposed research and complimentary mentorship and training plans will enable the applicant to: 1) gain expertise in intervention adaptation and clinical trial research; 2) gain expertise in sexual minority health; 3) develop aptitude in implementation theory and processes to inform future implementation of the proposed intervention and other interventions; and 4) achieve career independence. The results of the pilot RCT along with the training and mentorship of this project will inform a Merit award submission comparing EWMS with an active control in a hybrid I implementation-effectiveness trial to test the efficacy of the intervention while collecting information on barriers and facilitators to implementation of the intervention. This proposed research, training, and mentorship plan will provide the applicant with the necessary skills and experience to transition into an independent clinical researcher in VA focused on the development, enhancement, and implementation of interventions for minority related stress among sexual minority Veterans. The research and training will take place at the National Center for Posttraumatic Stress Disorder at the VA Boston Healthcare System under the supportive, collaborative, and accomplished mentorship team, including Drs. Brian Marx (primary mentor), Katherine Iverson (co-mentor), and Nicholas Livingston (co-mentor). These mentors have unique, yet complimentary, areas of expertise and have an established and successful history working together and with the applicant. The research, mentorship, and training proposed will facilitate the applicant's transition into a successful and productive independent VA investigator conducting research that directly aligns with VA's priority to provide equitable, patient-centered services to Veterans.